[Code of Federal Regulations]
[Title 49, Volume 6]
[Revised as of October 1, 2005]
From the U.S. Government Printing Office via GPO Access
[CITE: 49CFR571.106]
[Page 253-289]
TITLE 49--TRANSPORTATION
OF TRANSPORTATION
PART 571_FEDERAL MOTOR VEHICLE SAFETY STANDARDS--Table of Contents
Subpart B_Federal Motor Vehicle Safety Standards
Sec. 571.106 Standard No. 106; Brake hoses.
S1. Scope. This standard specifies labeling and performance
requirements for motor vehicle brake hose, brake hose assemblies, and
brake hose end fittings.
S2. Purpose. The purpose of this standard is to reduce deaths and
injuries occurring as a result of brake system failure from pressure or
vacuum loss due to hose or hose assembly rupture.
S3. Application. This standard applies to passenger cars,
multipurpose passenger vehicles, trucks, buses, trailers, and
motorcycles, and to hydraulic, air, and vacuum brake hose, brake hose
assemblies, and brake hose end fittings for use in those vehicles.
S4. Definitions.
Armor means protective material installed on a brake hose to
increase the resistance of the hose or hose assembly to abrasion or
impact damage.
Brake hose means a flexible conduit, other than a vacuum tubing
connector, manufactured for use in a brake system to transmit or contain
the fluid pressure or vacuum used to apply force to a vehicle's brakes.
For hose, a dimensional description such as ``\1/4\-inch hose'' refers
to the nominal inside diameter. For tubing, a dimensional description
such as ``\1/4\-in tubing'' refers to the nominal outside diameter.
Brake hose assembly means a brake hose, with or without armor,
equipped with end fittings for use in a brake system, but does not
include an air or vacuum assembly prepared by the owner or operator of a
used vehicle, by his employee, or by a repair facility, for installation
in that used vehicle.
Brake hose end fitting means a coupler, other than a clamp, designed
for attachment to the end of a brake hose.
Free length means the linear measurement of hose exposed between the
end fittings of a hose assembly in a straight position.
Permanently attached end fitting means an end fitting that is
attached by deformation of the fitting about the hose by crimping or
swaging, or an end fitting that is attached by use of a sacrificial
sleeve or ferrule that requires replacement each time a hose assembly is
rebuilt.
Rupture means any failure that results in separation of a brake hose
from its end fitting or in leakage.
Vacuum tubing connector means a flexible conduit of vacuum that (i)
connects metal tubing to metal tubing in a brake system, (ii) is
attached without end fittings, and (iii) when installed, has an
unsupported length less than the total length of those portions that
cover the metal tubing.
S5. Requirements--hydraulic brake hose, brake hose assemblies, and
brake hose end fittings.
S5.1 Construction. (a) Each hydraulic brake hose assembly shall have
permanently attached brake hose end fittings which are attached by
deformation of the fitting about the hose by crimping or swaging.
(b) Each hydraulic brake hose assembly that is equipped with a
permanent supplemental support integrally attached to the assembly and
is manufactured as a replacement for use on a vehicle not equipped, as
an integral part of the vehicle's original design, with a means of
attaching the support to the vehicle shall be equipped with a bracket
that is integrally attached to the supplemental support and that adapts
the vehicle to properly accept this type of brake hose assembly.
S5.2 Labeling.
S5.2.1 Each hydraulic brake hose, except hose sold as part of a
motor vehicle, shall have at least two clearly identifiable stripes of
at least one-sixteenth of an inch in width, placed on opposite sides of
the brake hose parallel to its longitudinal axis. One stripe may be
interrupted by the information required by S5.2.2, and the other stripe
may be interrupted by additional information at the manufacturer's
option. However, hydraulic brake hose manufactured for use only in an
assembly whose end fittings prevent its installation in a twisted
orientation in either side of the vehicle, need not meet the
requirements of S5.2.1.
S5.2.2 Each hydraulic brake hose shall be labeled, or cut from bulk
hose that is labeled, at intervals of not more than 6 inches, measured
from the end of one legend to the beginning of the next, in block
capital letters and numerals at least one-eighth of an inch high, with
the information listed in
[[Page 254]]
paragraphs (a) through (e) of this section. The information need not be
present on hose that is sold as part of a brake hose assembly or a motor
vehicle.
(a) The symbol DOT, constituting a certification by the hose
manufacturer that the hose conforms to all applicable motor vehicle
safety standards.
(b) A designation that identifies the manufacturer of the hose,
which shall be filed in writing with: Office of Crash Avoidance
Standards, Vehicle Dynamics Division, National Highway Traffic Safety
Administration, 400 Seventh Street, SW., Washington, DC 20590. The
marking may consist of a designation other than block capital letters
required by S5.2.2.
(c) The month, day, and year, or the month and year, of manufacture,
expressed in numerals. For example, 10/1/96 means October 1, 1996.
(d) The nominal inside diameter of the hose expressed in inches or
fractions of inches, or in millimeters followed by the abbreviation
``mm.''
(e) Either ``HR'' to indicate that the hose is regular expansion
hydraulic hose or ``HL'' to indicate that the hose is low expansion
hydraulic hose.
S5.2.3 Package labeling for brake hose assemblies designed to be
used with a supplemental support. (a) Each hydraulic brake hose assembly
that is equipped with a permanent supplemental support integrally
attached to the assembly and is manufactured as a replacement assembly
for a vehicle equipped, as an integral part of the vehicle's original
design, with a means of attaching the support to the vehicle shall be
sold in a package that is marked or labeled as follows: ``FOR USE ON
[insert Manufacturer, Model Name] ONLY'';
(b) Each hydraulic brake hose assembly that is equipped with a
permanent supplemental support integrally attached to the assembly and
is manufactured as a replacement for use on a vehicle not equipped, as
an integral part of the vehicle's original design, with a means of
attaching the support to the vehicle shall comply with paragraphs (a)
(1) and (2) of this section:
(1) Be sold in a package that is marked or labeled as follows: ``FOR
USE ONLY WITH A SUPPLEMENTAL SUPPORT.''
(2) Be accompanied by clear, detailed instructions explaining the
proper installation of the brake hose and the supplemental support
bracket to the vehicle and the consequences of not attaching the
supplemental support bracket to the vehicle. The instructions shall be
printed on or included in the package specified in paragraph (a)(1) of
this section.
S5.2.4 Each hydraulic brake hose assembly, except those sold as part
of a motor vehicle, shall be labeled by means of a band around the brake
hose assembly as specified in this paragraph or, at the option of the
manufacturer, by means of labeling as specified in S5.2.4.1. The band
may at the manufacturer's option be attached so as to move freely along
the length of the assembly, as long as it is retained by the end
fittings. The band shall be etched, embossed, or stamped in block
capital letters, numerals or symbols at least one-eighth of an inch
high, with the following information:
(a) The symbol DOT constituting certification by the hose assembler
that the hose assembly conforms to all applicable motor vehicle safety
standards.
(b) A designation that identifies the manufacturer of the hose
assembly, which shall be filed in writing with: Office of Crash
Avoidance Standards, Vehicle Dynamics Division, National Highway Traffic
Safety Administration, 400 Seventh Street SW., Washington, DC 20590. The
designation may consist of block capital letters, numerals or a symbol.
S5.2.4.1 At least one end fitting of a hydraulic brake hose assembly
shall be etched, stamped or embossed with a designation at least one-
sixteenth of an inch high that identifies the manufacturer of the hose
assembly and is filed in accordance with S5.2.4(b).
S5.3 Test requirements. A hydraulic brake hose assembly or
appropriate part thereof shall be capable of meeting any of the
requirements set forth under this heading, when tested under the
conditions of S11 and the applicable procedures of S6. However, a
particular hose assembly or appropriate part
[[Page 255]]
thereof need not meet further requirements after having been subjected
to and having met the constriction requirement (S5.3.1) and any one of
the requirements specified in S5.3.2 through S5.3.11.
S5.3.1 Constriction. Except for that part of an end fitting which
does not contain hose, every inside diameter of any section of a
hydraulic brake hose assembly shall be not less than 64 percent of the
nominal inside diameter of the brake hose.
S5.3.2 Expansion and burst strength. The maximum expansion of a
hydraulic brake hose assembly at 1,000 psi and 1,500 psi shall not
exceed the values specified in Table I (S6.1). The hydraulic brake hose
assembly shall then withstand water pressure of 4,000 psi for 2 minutes
without rupture, and shall not rupture at less than 5,000 psi (S6.2).
Table 1--Maximum Expansion of Free Length Brake Hose, cc/ft.
------------------------------------------------------------------------
Test Pressure
-------------------------------------------
1,000 psi 1,500 psi
Hydraulic brake hose, inside -------------------------------------------
diameter Regular Low Regular Low
expansion expansion expansion expansion
hose hose hose hose
------------------------------------------------------------------------
\1/8\ inch or 3 mm or less.. 0.66 0.33 0.79 0.42
\3/16\ inch or 4 to 5 mm.... .86 .55 1.02 .72
\1/4\ inch or 6 mm or more.. 1.04 .82 1.30 1.17
------------------------------------------------------------------------
S5.3.3 Whip resistance. A hydraulic brake hose assembly shall not
rupture when run continuously on a flexing machine for 35 hours (S6.3).
S5.3.4 Tensile strength. A hydraulic brake hose assembly shall
withstand a pull of 325 pounds without separation of the hose from its
end fittings (S6.4).
S5.3.5 Water absorption and burst strength. A hydraulic brake hose
assembly, after immersion in water for 70 hours (S6.5), shall withstand
water pressure of 4,000 psi for 2 minutes, and then shall not rupture at
less than 5,000 psi (S6.2).
S5.3.6 Water absorption and tensile strength. A hydraulic brake hose
assembly, after immersion in water for 70 hours (S6.5), shall withstand
a pull of 325 pounds without separation of the hose from its end
fittings (S6.4).
S5.3.7 Water absorption and whip resistance. A hydraulic brake hose
assembly, after immersion in water for 70 hours (S6.5), shall not
rupture when run continuously on a flexing machine for 35 hours (S6.3).
S.5.3.8 Low-temperature resistance. A hydraulic brake hose
conditioned at minus 40 [deg]F. for 70 hours shall not show cracks
visible without magnification when bent around a cylinder as specified
in S6.6. (S6.6)
S5.3.9 Brake fluid compatibility, constriction, and burst strength.
Except for brake hose assemblies designed for use with mineral or
petroleum-based brake fluids, a hydraulic brake hose assembly shall meet
the constriction requirement of S5.3.1 after having been subjected to a
temperature of 200 [deg]F for 70 hours while filled with SAE RM-66-04
Compatibility Fluid, as described in appendix B of SAE Standard J1703
JAN 1995, ``Motor Vehicle Brake Fluid.'' It shall then withstand water
pressure of 4,000 psi for 2 minutes and thereafter shall not rupture at
less than 5,000 psi (S6.2). (SAE RM-66-03 Compatibility Fluid, as
described in appendix A of SAE Standard J1703 NOV83, ``Motor Vehicle
Brake Fluid,'' November 1983, may be used in place of SAE RM-66-04 until
January 1, 1995.)
S5.3.10 Ozone resistance. A hydraulic brake hose shall not show
cracks visible under 7-power magnification after exposure to ozone for
70 hours at 104 [deg]F. (S6.8).
S5.3.11 End fitting corrosion resistance. After 24 hours of exposure
to salt spray, a hydraulic brake hose end fitting shall show no base
metal corrosion on the end fitting surface except where crimping or the
application of labeling information has caused displacement of the
protective coating. (S6.9)
S6. Test procedures--Hydraulic brake hose, brake hose assemblies,
and brake hose end fittings.
S6.1. Expansion test.
S6.1.1 Apparatus. Utilize a test apparatus (as shown in Figure 1)
which consists of:
(a) Source for required fluid pressure;
(b) Test fluid of water without any additives and free of gases;
(c) Reservoir for test fluid;
(d) Pressure gauges;
[[Page 256]]
(e) Brake hose end fittings in which to mount the hose vertically;
and
(f) Graduate burette with 0.05 cc increments.
[GRAPHIC] [TIFF OMITTED] TC01AU91.006
Fig. 1--Expansion Test Apparatus
S6.1.2 Preparation. (a) Measure the free length of the hose
assembly.
(b) Mount the hose so that it is in a vertical straight position
without tension when pressure is applied.
(c) Fill the hose with test fluid and bleed all gases from the
system.
(d) Close the valve to the burette and apply 1,500 psi for 10
seconds; then release pressure.
S6.1.3 Calculation of expansion at 1,000 and 1,500 psi. (a) Adjust
the fluid level in the burette to zero.
(b) Close the valve to the burette, apply pressure at the rate of
15,000 psi per minute, and seal 1,000 psi in the hose (1,500 psi in
second series).
(c) After 3 seconds open the valve to the burette for 10 seconds and
allow the fluid in the expanded hose to rise into the burette.
(d) Repeat the procedure in steps (b) and (c) twice. Measure the
amount of test fluid which has accumulated in the burette as a result of
the three applications of pressure.
(e) Calculate the volumetric expansion per foot by dividing the
total accumulated test fluid by 3 and further dividing by the free
length of the hose in feet.
S6.2 Burst strength test. (a) Connect the brake hose to a pressure
system and fill it completely with water, allowing all gases to escape.
(b) Apply water pressure of 4,000 psi at a rate of 15,000 psi per
minute.
(c) After 2 minutes at 4,000 psi, increase the pressure at the rate
of 15,000 psi per minute until the pressure exceeds 5,000 psi.
S6.3 Whip resistance test.
S6.3.1 Apparatus. Utilize test apparatus that is dynamically
balanced and includes:
(a) A movable header consisting of a horizontal bar equipped with
capped end fittings and mounted through bearings at each end to points 4
inches from the center of two vertically rotating disks whose edges are
in the same vertical plane;
(b) An adjustable stationary header parallel to the movable header
in the same horizontal plane as the centers of the disks, and fitted
with open end fittings;
(c) An elapsed time indicator; and
(d) A source of water pressure connected to the open end fittings.
S6.3.2 Preparation. (a) Except for the supplemental support
specified in S6.3.2(d), remove all external appendages including, but
not limited to, hose armor, chafing collars, mounting brackets, date
band and spring guards.
(b) Measure the hose free length.
(c) Mount the hose in the whip test machine, introducing slack as
specified in Table II for the size hose tested, measuring the projected
length parallel to the axis of the rotating disks. The manufacturer may,
at his option, adapt the fitting attachment points to permit mounting
hose assemblies equipped with angled or other special fittings in the
same orientation as hose assemblies equipped with straight fittings.
(d) In the case of a brake hose assembly equipped with a permanent
supplemental support integrally attached to the assembly, the assembly
may be mounted using the supplemental support and associated means of
simulating its attachment to the vehicle. Mount the supplemental support
in the same vertical and horizontal planes as the stationary header end
of the whip test fixture described in S6.3.1(b).
[[Page 257]]
Mount or attach the supplemental support so that it is positioned in
accordance with the recommendation of the assembly manufacturer for
attaching the supplemental support on a vehicle.
Table II--Hose Lengths
------------------------------------------------------------------------
Slack, inches
-----------------------
\1/8\ inch More than
Free length between end fittings, inches or 3 mm \1/8\ inch
hose or or 3 mm
less hose
------------------------------------------------------------------------
8 to 15\1/2\, inclusive......................... 1.750 ..........
10 to 15\1/2\, inclusive........................ .......... 1,000
Over 15\1/2\ to 19 inclusive.................... 1.250 ..........
Over 19 to 24, inclusive........................ 0.750 ..........
------------------------------------------------------------------------
S6.3.3 Operation. (a) Apply 235 psi water pressure and bleed all
gases from the system.
(b) Drive the movable head at 800 rpm.
S6.4 Tensile strength test. Utilize a tension testing machine
conforming to the requirements of the methods of Verification of Testing
Machines (1964 American Society for Testing and Materials, Designation
E4), and provided with a recording device to give the total pull in
pounds.
S6.4.1 Preparation. Mount the hose assembly to ensure straight,
evenly distributed machine pull.
S6.4.2 Operation. Apply tension at a rate of 1 inch per minute
travel of the moving head until separation occurs.
S6.5 Water absorption sequence tests.
S6.5.1 Preparation. Prepare three hose assemblies as follows:
(a) Remove 1\1/8\ inches of hose cover, if any, from the center of
the hose assemblies without injury to any reinforcing material or
elongation of the hose assemblies.
(b) Measure the free length of the hose assemblies.
S.6.5.2 Immersion and sequence testing. (a) Immerse the hose
assemblies in distilled water for 70 hours.
(b) Thirty minutes after removal from water, conduct tests S6.2,
S6.3, and S6.4, using a different hose for each sequence.
S6.6 Low temperature resistance test.
S6.6.1 Preparation. (a) Remove hose armor, if any, and condition a
hose in a straight position in air at minus 40 [deg]F. for 70 hours.
(b) Condition a cylinder in air at minus 40 [deg]F for 70 hours,
using a cylinder of 2\1/2\ inches diameter for test of hose less than
\1/8\ inch or 3 mm 3 inches for tests of \1/8\ inch or 3mm hose, 3\1/2\
inches for tests of \3/16\ and \1/4\ inch hose or of 4 to 6 mm hose, and
4 inches for tests of hose greater than \1/4\ inch or 6 mm in diameter.
S6.6.2 Flexibility testing. Bend the conditioned hose 180 degrees
around the conditioned cylinder at a steady rate in a period of 3 to 5
seconds. Examine without magnification for cracks.
S6.7 Brake fluid compatibility test.
S6.7.1 Preparation. (a) Attach a hose assembly below a 1-pint
reservoir filled with 100 ml. of SAE RM-66-04 Compatibility Fluid as
shown in Figure 2. (SAE RM-66-03 Compatibility Fluid, as described in
appendix A of SAE Standard J1703 NOV83, ``Motor Vehicle Brake Fluid,''
November 1983, may be used in place of SAE RM-66-04 until January 1,
1995.)
(b) Fill the hose assembly with brake fluid, seal the lower end, and
place the test assembly in an oven in a vertical position.
[GRAPHIC] [TIFF OMITTED] TC01AU91.007
S6.7.2 Oven treatment. (a) Condition the hose assembly at 200
[deg]F. for 70 hours.
(b) Cool the hose assembly at room temperature for 30 minutes.
[[Page 258]]
(c) Drain the brake hose assembly, immediately determine that every
inside diameter of any section of the hose assembly, except for that
part of an end fitting which does not contain hose, is not less than 64
percent of the nominal inside diameter of the hose, and conduct the test
specified in S6.2.
S6.8 Ozone resistance test. Utilize a cylinder with a diameter eight
times the nominal outside diameter of the brake hose excluding armor.
S6.8.1 Preparation. After removing any armor, bind a hydraulic brake
hose 360[deg] around the cylinder. In the case of hose shorter than the
circumference of the cylinder, bend the hose so that as much of its
length as possible is in contact.
S6.8.2 Exposure to ozone. (a) Condition the hose on the cylinder in
air at room temperature for 24 hours.
(b) Immediately thereafter, condition the hose on the cylinder for
70 hours in an exposure chamber having an ambient air temperature of 104
[deg]F. during the test and containing air mixed with ozone in the
proportion of 50 parts of ozone per 100 million parts of air by volume.
(c) Examine the hose for cracks under 7-power magnification,
ignoring areas immediately adjacent to or within the area covered by
binding.
S6.9 End fitting corrosion resistance test. Utilize the apparatus
described in ASTM B117-64, ``Salt Spray (Fog) Testing''.
S6.9.1 Construction. Construct the salt spray chamber so that:
(a) The construction material does not affect the corrosiveness of
the fog.
(b) The hose assembly is supported or suspended 30[deg] from the
vertical and parallel to the principal direction of the horizontal flow
of fog through the chamber.
(c) The hose assembly does not contact any metallic material or any
material capable of acting as a wick.
(d) Condensation which falls from the assembly does not return to
the solution reservoir for respraying.
(e) Condensation from any source does not fall on the brake hose
assemblies or the solution collectors.
(f) Spray from the nozzles is not directed onto the hose assembly.
S6.9.2 Preparation. (a) Plug each end of the hose assembly.
(b) Mix a salt solution five parts by weight of sodium chloride to
95 parts of distilled water, using sodium chloride substantially free of
nickel and copper, and containing on a dry basis not more than 0.1
percent of sodium iodide and not more than 0.3 percent total impurities.
Ensure that the solution is free of suspended solids before the solution
is atomized.
(c) After atomization at 95 [deg]F. ensure that the collected
solution is in the PH range of 6.5 to 7.2. Make the PH measurements at
77 [deg]F.
(d) Maintain a compressed air supply to the nozzle or nozzles free
of oil and dirt and between 10 and 25 psi.
S6.9.3 Operation. Subject the brake hose assembly to the salt spray
continuously for 24 hours.
(a) Regulate the mixture so that each collector will collect from 1
to 2 ml. of solution per hour for each 80 square centimeters of
horizontal collecting area.
(b) Maintain exposure zone temperature at 95 [deg]F.
(c) Upon completion, remove the salt deposit from the surface of the
hoses by washing gently or dipping in clean running water not warmer
than 100 [deg]F. and then drying immediately.
S7. Requirements--Air brake hose, brake hose assemblies, and brake
hose end fittings.
S7.1 Construction. Each air brake hose assembly shall be equipped
with permanently attached brake hose end fittings or reusable brake hose
end fittings. Each air brake hose constructed of synthetic or natural
elastomeric rubber intended for use with reusable end fittings shall
conform to the dimensional requirements specified in Table III.
[[Page 259]]
Table III--Air Brake Hose Dimensions for Reusable Assemblies
----------------------------------------------------------------------------------------------------------------
Type I outside diameter, Type II outside
Inside diameter inches diameter, inches
Size, inches tolerance, inches ---------------------------------------------------
Minimum Maximum Minimum Maximum
----------------------------------------------------------------------------------------------------------------
\3/16\................................... +0.026 0.472 0.510 0.500 0.539
-0.000
\1/4\.................................... +0.031 0.535 0.573 0.562 0.602
-0.000
\5/16\................................... +0.031 0.598 0.636 0.656 0.695
-0.000
\3/8\.................................... 0.023
\13/32\.................................. +0.031 0.714 0.760 0.742 0.789
-0.000
\1/2\.................................... +0.039 0.808 0.854 0.898 0.945
-0.000
\5/8\.................................... +0.042 0.933 0.979 1.054 1.101
-0.000
\1/2\ special............................ .031
----------------------------------------------------------------------------------------------------------------
S7.2 Labeling
S7.2.1 Hose. Each air brake hose shall be labeled, or cut from bulk
hose that is labeled, at intervals of not more than 6 inches, measured
from the end of one legend to the beginning of the next, in block
capital letters and numerals at least one-eighth of an inch high, with
the information listed in paragraphs (a) through (e) of this section.
The information need not be present on hose that is sold as part of a
brake hose assembly or a motor vehicle.
(a) The symbol DOT, constituting a certification by the hose
manufacturer that the hose conforms to all applicable motor vehicle
safety standards.
(b) A designation that identifies the manufacturer of the hose,
which shall be filed in writing with: Office of Crash Avoidance
Standards, Vehicle Dynamics Division, National Highway Traffic Safety
Administration, 400 Seventh Street SW., Washington, DC 20590. The
designation may consist of block capital letters, numerals, or a symbol.
(c) The month, day, and year, or the month and year, of manufacture,
expressed in numerals. For example, 10/1/96 means October 1, 1996.
(d) The nominal inside diameter of the hose expressed in inches or
fractions of inches or in millimeters, or the nominal outside diameter
of plastic tubing expressed in inches or fractions of inches or in
millimeters followed by the letters OD. The abbreviation ``mm'' shall
follow hose sizes that are expressed in millimeters. (Examples of inside
diameter: \1/8\, \1/2\ (\1/2\SP in the case of \1/2\ inch special air
brake hose), 4 mm, 6 mm. Examples of outside diameter: \1/4\ OD, 12 mm
OD.)
(e) The letter ``A'' shall indicate intended use in air brake
systems. In the case of a hose constructed of synthetic or natural
elastomeric rubber intended for use in a reusable assembly, ``AI'' or
``AII'' shall indicate Type I or Type II dimensional characteristics of
the hose as described in Table III.
S7.2.2 End fittings. Except for an end fitting that is attached by
deformation of the fitting about a hose by crimping or swaging, at least
one component of each air brake hose fitting shall be etched, embossed,
or stamped in block capital letters and numerals at least one-sixteenth
of an inch high with the following information:
(a) The symbol DOT, constituting a certification by the manufacturer
of that component that the component conforms to all applicable motor
vehicle safety standards.
(b) A designation that identifies the manufacturer of that component
of the fitting, which shall be filed in writing with: Office of Crash
Avoidance Standards, Vehicle Dynamics Division, National Highway Traffic
Safety Administration, 400 Seventh Street SW., Washington, DC 20590. The
designation may consist of block capital letters, numerals, or a symbol.
(c) The letter ``A'' shall indicate intended use in air brake
systems. In the case of an end fitting intended for use in a reusable
assembly with brake hose
[[Page 260]]
subject to Table III, ``AI'' or ``AII'' shall indicate use with Type I
or Type II hose, respectively.
(d) The nominal inside diameter of the hose to which the fitting is
properly attached expressed in inches or fractions of inches or in
millimeters, or the outside diameter of the plastic tubing to which the
fitting is properly attached expressed in inches or fractions of inches
or in millimeters followed by the letters OD (See examples in
S7.2.1(d)). The abbreviations ``mm'' shall follow hose sizes that are
expressed in millimeters.
S7.2.3 Assemblies. Each air brake hose assembly made with end
fittings that are attached by crimping or swaging, except those sold as
part of a motor vehicle, shall be labeled by means of a band around the
brake hose assembly as specified in this paragraph or, at the option of
the manufacturer, by means of labeling as specified in S7.2.3.1. The
band may at the manufacturer's option be attached so as to move freely
along the length of the assembly, as long as it is retained by the end
fittings. The band shall be etched, embossed, or stamped in block
capital letters, numerals or symbols at least one-eighth of an inch
high, with the following information:
(a) The symbol DOT, constituting certification by the hose assembler
that the hose assembly conforms to all applicable motor vehicle safety
standards.
(b) A designation that identifies the manufacturer of the hose
assembly, which shall be filed in writing with: Office of Crash
Avoidance Standards, Vehicle Dynamics Division, National Highway Traffic
Safety Administration, 400 Seventh Street SW., Washington, DC 20590. The
designation may consist of block capital letters, numerals or a symbol.
S7.2.3.1 At least one end fitting of an air brake hose assembly made
with end fittings that are attached by crimping or swaging shall be
etched, stamped or embossed with a designation at least one-sixteenth of
an inch high that identifies the manufacturer of the hose assembly and
is filed in accordance with S7.2.3(b).
S7.3 Test requirements. Each air brake hose assembly or appropriate
part thereof shall be capable of meeting any of the requirements set
forth under this heading, when tested under the conditions of S11 and
the applicable procedures of S8. However, a particular hose assembly or
appropriate part thereof need not meet further requirements after having
met the constriction requirement (S7.3.1) and then having been subjected
to any one of the requirements specified in S7.3.2 through S7.3.13.
S7.3.1 Construction. Except for that part of an end fitting which
does not contain hose, every inside diameter of any section of an air
brake hose assembly shall be not less than 66 percent of the nominal
inside diameter of the brake hose.
S7.3.2 High temperature resistance. An air brake hose shall not show
external or internal cracks, charring, or disintegration visible without
magnification when straightened after being bent for 70 hours at 212
[deg]F. over a cylinder having the radius specified in Table IV for the
size of hose tested (S8.1).
S7.3.3 Low temperature resistance. The outer cover of an air brake
hose shall not show cracks visible without magnification as a result of
conditioning at minus 40 [deg]F. for 70 hours when bent around a
cylinder having the radius specified in Table IV for the size of hose
tested (S8.2).
Table IV--Air Brake Hose Diameters and Test Cylinder Radii
----------------------------------------------------------------------------------------------------------------
Nominal hose diameter, in.*.................... \1/8\ \3/16\ \1/4\ \5/16\ \3/8\, \13/ \7/16\, \1/ \5/8\
32\ 2\
mm.*........................................... 3 4, 5 6 8 10 12 16
Radius of test cylinder in inches.............. 1\1/2\ 2 2\1/2\ 3 3\1/2\ 4 4\1/2\
----------------------------------------------------------------------------------------------------------------
*These sizes are listed to provide test values for brake hoses manufactured in these sizes. They do not
represent conversions.
S7.3.4 Oil resistance. After immersion in ASTM No. 3 oil for 70
hours at 212 [deg]F. the volume of a specimen prepared from the inner
tube and cover of an air brake hose shall not increase more than 100
percent (S8.3).
[[Page 261]]
S7.3.5 Ozone resistance. The outer cover of an air brake hose shall
not show cracks visible under 7-power magnification after exposure to
ozone for 70 hours at 104 [deg]F. (S8.4).
S7.3.6 Length change. An airbrake hose (other than a coiled nylon
tube for use in an assembly that meets the requirements of Sec. 393.45
of this title) shall not contract in length more than 7 percent nor
elongate more than 5 percent when subjected to air pressure of 200 psi
(S8.5).
S7.3.7 Adhesion. Except for hose reinforced by wire, an airbrake
hose shall withstand a tensile force of 8 pounds per inch of length
before separation of adjacent layers (S8.6).
S7.3.8 Air pressure. An air brake hose assembly shall contain air
pressure of 200 psi for 5 minutes without loss of more than 5 psi
(S8.7).
S7.3.9 Burst strength. An air brake hose assembly shall not rupture
when exposed to hydrostatic pressure of 800 psi (S8.8).
S7.3.10 Tensile strength. An air brake hose assembly (other than a
coiled nylon tube assembly which meets the requirements of Sec. 393.45
of this title) designed for use between frame and axle or between a
towed and a towing vehicle shall withstand, without separation of the
hose from its end fittings, a pull of 250 pounds if it is \1/4\ inch or
less or 6 mm or less in nominal internal diameter, or a pull of 325
pounds if it is larger than \1/4\ inch or 6 mm in nominal internal
diameter. An air brake hose assembly designed for use in any other
application shall withstand, without separation of the hose from its end
fitting, a pull of 50 pounds if it is \1/4\ inch or 6 mm or less in
nominal internal diameter, 150 pounds if it is \3/8\ or \1/2\ inch or 10
mm to 12 mm in nominal internal diameter, or 325 pounds if it is larger
than \1/2\ inch or 12 mm in nominal internal diameter (S8.9).
S7.3.11 Water absorption and tensile strength. After immersion in
distilled water for 70 hours (S8.10), an air brake hose assembly (other
than a coiled tube assembly which meets the requirements of Sec. 393.45
of this title) designed for use between frame and axle or between a
towed and a towing vehicle shall withstand without separation of the
hose from its end fittings a pull of 250 pounds if it is \1/4\ inch or 6
mm or less in nominal internal diameter, or a pull of 325 pounds if it
is larger than \1/4\ inch or 6 mm in nominal internal diameter. After
immersion in distilled water for 70 hours (S8.10), an air brake hose
assembly designed for use in any other application shall withstand
without separation of the hose from its end fitting a pull of 50 pounds
if it is \1/4\ inch or 6 mm or less in nominal internal diameter, 150
pounds if it is \3/8\ inch or \1/2\ inch or 10 to 12 mm in nominal
internal diameter, or 325 pounds if it is larger than \1/2\ inch or 12
mm in nominal internal diameter (S8.9).
S7.3.12 Zinc chloride resistance. The outer cover of an air brake
hose shall not show cracks visible under 7-power magnification after
immersion in a 50 percent zinc chloride aqueous solution for 200 hours
(S8.11).
S7.3.13 End fitting corrosion resistance. After 24 hours of exposure
to salt spray, air brake hose end fittings shall show no base metal
corrosion on the end fitting surface except where crimping or the
application of labeling information causes a displacement of the
protective coating.
S8. Test procedures--Air brake hose, brake hose assemblies, and
brake hose end fittings.
S8.1 High temperature resistance test. (a) Utilize a cylinder having
the radius indicated in Table IV for the size of hose tested.
(b) Bind the hose around the cylinder and condition it in an air
oven for 70 hours at 212 [deg]F.
(c) Cool the hose to room temperature, remove it from the cylinder
and straighten it.
(d) Without magnification, examine the hose externally and cut the
hose lengthwise and examine the inner tube.
S8.2 Low temperature resistance test. (a) Utilize a cylinder having
the radius indicated in Table IV for the size of hose tested.
(b) Condition the cylinder and the brake hose, in a straight
position, in a cold box at minus 40 [deg]F. for 70 hours.
(c) With the hose and cylinder at minus 40 [deg]F., bend the hose
180 degrees around the cylinder at a steady rate in a period of 3 to 5
seconds.
S8.3 Oil resistance test. Utilize three test specimens and average
the results.
[[Page 262]]
S8.3.1 Preparation. Fashion a test specimen by cutting a rectangular
block 2 inches long and not less than one-third of an inch in width,
having a thickness of not more than one-sixteenth inch, from the brake
hose and buff the specimen on both faces to ensure smooth surfaces.
S8.3.2 Measurement. (a) Weigh each specimen to the nearest milligram
in air (W1) and in distilled water (W2) at room temperature. If wetting
is necessary to remove air bubbles, dip the specimen in acetone and
thoroughly rinse it with distilled water.
(b) Immerse each specimen in ASTM No. 3 oil for 70 hours at 212
[deg]F. and then cool in ASTM No. 3 oil at room temperature for 30 to 60
minutes.
(c) Dip the specimen quickly in acetone and blot it lightly with
filter paper.
(d) Weigh each specimen in a tared weighing bottle (W3) and in
distilled water (W4) within five minutes of removal from the cooling
liquid.
(e) Calculate the percentage increase in volume follows:
Percent of increase=
[(W3-W4)-(W1-W2)]/
(W1-W2)x100
S8.4 Ozone resistance test. Conduct the test specified in S6.8 using
air brake hose.
S8.5 Length change test. (a) Position a test hose in a straight,
horizontal position, and apply air pressure of 10 psi thereto.
(b) Measure the hose to determine original free length.
(c) Without releasing the 10 psi, raise the air pressure to the test
hose to 200 psi.
(d) Measure the hose under 200 psi to determine final free length.
An elongation or contraction is an increase or decrease, respectively,
in the final free length from the original free length of the hose.
S8.6 Adhesion test.
S8.6.1 Apparatus. A tension testing machine that is power-driven and
that applies a constant rate of extension is used for measuring the
force required to separate the layers of the test specimen. The
apparatus is constructed so that:
(a) The recording head includes a freely rotating form with an
outside diameter substantially the same as the inside diameter of the
hose specimen to be placed on it.
(b) The freely rotating form is mounted so that its axis of rotation
is in the plane of the ply being separated from the specimen and so that
the applied force is perpendicular to the tangent of the specimen
circumference at the line of separation.
(c) The rate of travel of the power-actuated grip is a uniform one
inch per minute and the capacity of the machine is such that maximum
applied tension during the test is not more than 85 percent nor less
than 15 percent of the machine's rated capacity.
(d) The machine produces a chart with separation as one coordinate
and applied tension as the other.
S8.6.2 Preparation. (a) Cut a test specimen of 1 inch or more in
length from the hose to be tested and cut the layer to be tested of that
test specimen longitudinally along its entire length to the level of
contact with the adjacent layer.
(b) Peel the layer to be tested from the adjacent layer to create a
flap large enough to permit attachment of the power-actuated clamp of
the apparatus.
(c) Mount the test specimen on the freely rotating form with the
separated layer attached to the power-actuated clamp.
S8.6.3 [Reserved]
S8.6.4 Calculations. (a) The adhesion value shall be the minimum
force recorded on the chart excluding that portion of the chart which
corresponds to the initial and final 20 percent portion along the
displacement axis.
(b) Express the force in pounds per inch of length.
S8.7 Air pressure test. (a) Connect the air brake hose assembly to a
source of air pressure.
(b) Apply 200 psi air pressure to the hose and seal the hose from
the source of air pressure.
(c) After 5 minutes, determine the air pressure remaining in the
test specimen.
S8.8 Burst strength test. (a) Utilize an air brake hose assembly.
(b) Fill the hose assembly with water, allowing all gases to escape.
Apply water pressure at a uniform rate
[[Page 263]]
of increase of approximately 1,000 psi per minute until the hose
ruptures.
S8.9 Tensile strength test. Utilize a tension testing machine
conforming to the requirements of the Methods of Verification of Testing
Machines (1964 American Society for Testing and Materials, Designation
E4), and provided with a recording device to register total pull in
pounds.
(a) Attach an air brake hose assembly to the testing machine to
permit straight, even, machine-pull on the hose.
(b) Apply tension at a rate of 1 inch per minute travel of the
moving head until separation occurs.
S8.10 Water Absorption and tensile strength test. Immerse an air
brake hose assembly in distilled water at room temperature for 70 hours.
Thirty minutes after removal from the water, conduct the test specified
in S8.9.
S8.11 Zinc chloride resistance test. Immerse an air brake hose in a
50 percent zinc chloride aqueous solution at room temperature for 200
hours. Remove it from the solution and examine it under 7-power
magnification for cracks.
S8.12 End fitting corrosion resistance test. Conduct the test
specified in S6.9 using an air brake hose assembly.
S9. Requirements--vacuum brake hose, brake hose assemblies, and
brake hose end fittings.
S9.1 Labeling.
S9.1.1 Hose. Each vacuum brake hose shall be labeled, or cut from
bulk hose that is labeled, at intervals of not more than 6 inches,
measured from the end of one legend to the beginning of the next, in
block capital letters and numerals at least one-eighth of an inch high,
with the information listed in paragraphs (a) through (e) of this
section. The information need not be present on hose that is sold as
part of a brake hose assembly or a motor vehicle. (a) The symbol DOT,
constituting a certification by the hose manufacturer that the hose
conforms to all applicable motor vehicle safety standards.
(b) A designation that identifies the manufacturer of the hose,
which shall be filed in writing with: Office of Crash Avoidance
Standards, Vehicle Dynamics Division, National Highway Traffic Safety
Administration, 400 Seventh Street, SW., Washington, DC 20590. The
designation may consist of block capital letters, numerals or a symbol.
(c) The month, day, and year, or the month and year, of manufacture,
expressed in numerals. For example, 10/1/96 means October 1, 1996.
(d) The nominal inside diameter of the hose expressed in inches or
fractions of inches or in millimeters, or the nominal outside diameter
of plastic tubing expressed in inches or fractions of inches or in
millimeters followed by the letters OD. The abbreviation ``mm'' shall
follow hose sizes that are expressed in millimeters. (Example of inside
diameter: \7/32\, \1/4\, 4 mm. Example of outside diameter: \1/4\ OD, 12
mm OD.)
(e) The letters ``VL'' or ``VH'' shall indicate that the component
is a light-duty vacuum brake hose or heavy-duty vacuum brake hose,
respectively.
S9.1.2 End fittings. Except for an end fitting that is attached by
heat striking or by interference fit with plastic vacuum hose or that is
attached by deformation of the fitting about a hose by crimping or
swaging, at least one component of each vacuum brake hose fitting shall
be etched, embossed, or stamped in block capital letters and numerals at
least one-sixteenth of an inch high with the following information:
(a) The symbol DOT, constituting a certification by the manufacturer
of that component that the component conforms to all applicable motor
vehicle safety standards.
(b) A designation that identifies the manufacturer of that component
of the fitting, which shall be filed in writing with: Office of Crash
Avoidance Standards, Vehicle Dynamics Division, National Highway Traffic
Safety Administration, 400 Seventh Street, SW., Washington, DC 20590.
The designation may consist of block capital letters, numerals or a
symbol.
(c) The letters ``VL'' or ``VH'' shall indicate that the end fitting
is intended for use in a light-duty or heavy-duty vacuum brake system,
respectively.
(d) The nominal inside diameter of the hose to which the fitting is
properly attached expressed in inches or fractions of inches or in
millimeters, or
[[Page 264]]
the outside diameter of the plastic tubing to which the fitting is
properly attached expressed in inches or fraction of inches or in
millimeters followed by the letter OD (See examples in S9.1.1(d)). The
abbreviation ``mm'' shall follow hose sizes that are expressed in
millimeters.
S9.1.3 Assemblies. Each vacuum brake hose assembly made with end
fittings that are attached by crimping or swaging and each plastic tube
assembly made with end fittings that are attached by heat shrinking or
dimensional interference fit, except those sold as part of a motor
vehicle, shall be labeled by means of a band around the brake hose
assembly as specified in this paragraph or, at the option of the
manufacturer, by means of labeling as specified in S9.1.3.1. The band
may at the manufacturer's option be attached so as to move freely along
the length of the assembly, as long as it is retained by the end
fittings. The band shall be etched, embossed, or stamped in block
capital letters, numerals or symbols at least one-eighth of an inch
high, with the following information:
(a) The symbol DOT, constituting certification by the hose assembler
that the hose assembly conforms to all applicable motor vehicle safety
standards.
(b) A designation that identifies the manufacturer of the hose
assembly, which shall be filed in writing with: Office of Crash
Avoidance Standards, Vehicle Dynamics Division, National Highway Traffic
Safety Administration, 400 Seventh Street SW., Washington, DC 20590. The
designation may consist of block capital letters, numerals or a symbol.
S9.1.3.1 At least one end fitting of a vacuum brake hose assembly
made with end fittings that are attached by crimping or swaging, or of a
plastic tubing assembly made with end fittings that are attached by heat
shrinking or dimensional interference fit shall be etched, stamped or
embossed with a designation at least one-sixteenth of an inch high that
identifies the manufacturer of the hose assembly and is filed in
accordance with S9.1.3(b).
S9.2 Test requirements. Each vacuum brake hose assembly or
appropriate part thereof shall be capable of meeting any of the
requirements set forth under this heading, when tested under the
conditions of S11. and the applicable procedures of S10. However, a
particular hose assembly or appropriate part thereof need not meet
further requirements after having met the construction requirement
(S9.2.1) and then having been subjected to any one of the requirements
specified in S9.2.2 through S9.2.11.
S9.2.1 Constriction. Except for that part of an end fitting which
does not contain hose, every inside diameter of any section of a vacuum
brake hose assembly shall be not less than 75 percent of the nominal
inside diameter of the hose if for heavy duty, or 70 percent of the
nominal inside diameter of the hose if for light duty.
S9.2.2 High temperature resistance. A vacuum brake hose shall not
show external or internal cracks, charring, or disintegration visible
without magnification when straightened after being bent for 70 hours at
212 [deg]F. over a cylinder having the radius specified in Table V for
the size of hose tested (S10.1).
S9.2.3 Low temperature resistance. A vacuum brake hose shall not
show cracks visible without magnification after conditioning at minus 40
[deg]F. for 70 hours when bent around a cylinder having the radius
specified in Table V for the size hose tested (S10.2).
S9.2.4 Ozone resistance. A vacuum brake hose shall not show cracks
visible under 7-power magnification after exposure to ozone for 70 hours
(S10.3).
S9.2.5 Burst strength. A vacuum brake hose shall not rupture under
hydrostatic pressure of 350 psi (S10.4).
S9.2.6 Vacuum. The collapse of the outside diameter of a vacuum
brake hose under internal vacuum of 26 inches of Hg. for five minutes
shall not exceed one-sixteenth of an inch (S10.5).
S9.2.7 Bend. The collapse of the outside diameter of a vacuum brake
hose at the middle point of the test length when bent until the ends
touch shall not exceed the values given in Table V for the size of hose
tested (S10.6).
[[Page 265]]
Table V--Vacuum Brake Hose Test Requirements
----------------------------------------------------------------------------------------------------------------
Hose inside diameter* High temperature Low temperature Bend
---------------------- resistance resistance ----------------------
-------------------------------------------- Maximum Deformation--collapsed
Hose collapse inside diameter
Inches Millimeters Hose Radius of Hose Radius of length, of outside (dimension D), inches
length, cylinder, length, cylinder, inches diameter,
inches inches inches inches inches
----------------------------------------------------------------------------------------------------------------
\7/32\ 5 8 1\1/2\ 17\1/2\ 3 7 \11/64\ \3/64\
\1/4\ 6 9 1\1/2\ 17\1/2\ 3 8 \3/32\ \1/16\
\9/32\ ............ 9 1\3/4\ 19 3\1/2\ 9 \12/64\ \4/64\
\11/32\ 8 9 1\3/4\ 19 3\1/2\ 11 \13/64\ \5/64\
\3/8\ 10 10 1\3/4\ 19 3\1/2\ 12 \5/32\ \3/32\
\7/16\ ............ 11 2 20\1/2\ 4 14 \17/64\ \5/64\
\15/32\ ............ 11 2 20\1/2\ 4 14 \17/64\ \5/64\
\1/2\ 12 11 2 20\1/2\ 4 16 \7/32\ \1/8\
\5/8\ 16 12 2\1/4\ 22 4\1/2\ 22 \7/32\ \5/32\
\3/4\ ............ 14 2\1/2\ 24 5 28 \7/32\ \3/16\
1 ............ 16 3\1/4\ 28\1/2\ 6\1/2\ 36 \9/32\ \1/4\
----------------------------------------------------------------------------------------------------------------
*These sizes are listed to provide test values for brake hoses manufactured in these sizes. They do not
represent conversions.
S9.2.8 Swell. Following exposure to Reference Fuel A, every inside
diameter of any section of a vacuum brake hose shall not be less than 75
percent of the nominal inside of the hose if for heavy duty, or 70
percent of the nominal inside diameter of the hose if for light duty.
The vacuum brake hose shall show no leakage and there shall be no
separation of the inner tube from the fabric reinforcement of the hose
in a vacuum test of 26 inches of Hg for 10 minutes (S10.7).
S9.2.9 Adhesion. Except for hose reinforced by wire, a vacuum brake
hose shall withstand a force of 8 pounds per inch of length before
separation of adjacent layers (S10.8).
S9.2.10 Deformation. A vacuum brake hose shall return to 90 percent
of its original outside diameter within 60 seconds after five
applications of force as specified in S10.9, except that a wire-
reinforced hose need only return to 85 percent of its original outside
diameter. In the case of heavy-duty hose the first application of force
shall not exceed a peak value of 70 pounds, and the fifth application of
force shall reach a peak value of at least 40 pounds. In the case of
lightduty hose the first application of force shall not exceed a peak
value of 50 pounds, and the fifth application of force shall reach a
peak value of at least 20 pounds (S10.9).
S9.2.11 End fitting corrosion resistance. After 24 hours of exposure
to salt spray, vacuum brake hose end fittings shall show no base metal
corrosion of the end fitting surface except where crimping or the
application of labeling information has caused displacement of the
protective coating.
S10. Test procedures--Vacuum brake hose, brake hose assemblies, and
brake hose end fittings.
S10.1 High temperature resistance test. Conduct the test specified
in S8.1 using vacuum brake hose with the cylinder radius specified in
Table V for the size of hose tested.
S10.2 Low temperature resistance test. Conduct the test specified in
S8.2 using vacuum brake hose with the cylinder radius specified in Table
V for the size of hose tested.
S10.3 Ozone resistance test. Conduct the test specified in S6.8
using vacuum brake hose.
S10.4 Burst strength test. Conduct the test specified in S8.8 using
vacuum brake hose.
S10.5 Vacuum test. Utilize a 12-inch vacuum brake hose assembly
sealed at one end. (a) Measure the hose outside diameter.
(b) Attach the hose to a source of vacuum and subject it to a vacuum
of 26 inches of Hg for 5 minutes.
(c) Measure the hose to determine the minimum outside diameter while
the hose is still subject to vacuum.
S10.6 Bend test. (a) Bend a vacuum brake hose, of the length
prescribed in Table V, in the direction of its normal curvature until
the ends just touch as shown in Figure 3.
(b) Measure the outside diameter of the specimen at point A before
and after bending.
[[Page 266]]
(c) The difference between the two measurements is the collapse of
the hose outside diameter on bending.
[GRAPHIC] [TIFF OMITTED] TC01AU91.008
Fig. 3--Bend Test of Vacuum Brake Hose.
S10.7 Swell test. (a) Fill a specimen of vacuum brake hose 12 inches
long with Reference Fuel A as described in the Method of Test for Change
in Properties of Elastomeric Vulcanizers Resulting From Immersion in
Liquids (1964 American Society for Testing and Materials, designation
D471).
(b) Maintain reference fuel in the hose under atmospheric pressure
at room temperature for 48 hours.
(c) Remove fuel and determine that every inside diameter of any
section of the brake hose is not less than 75 percent of the nominal
inside diameter of the hose for heavy-duty hose and 70 percent of the
nominal inside diameter of the hose for light-duty hose.
(d) Subject the hose specimen to a vacuum of 26 inches of Hg for 10
minutes.
S10.8 Adhesion test. Conduct the test specified in S8.6 using vacuum
brake hose.
S10.9 Deformation test. Table VI specifies the test specimen
dimensions.
S10.9.1 Apparatus. Utilize a compression device, equipped to measure
force of at least 100 pounds, and feeler gages of sufficient length to
be passed completely through the test specimen.
S10.9.2 Operation. (a) Position the test specimen longitudinally in
the compression device with the fabric laps not in the line of the
applied pressure.
Table VI--Dimensions of Test Specimen and Feeler Gage for Deformation
Test
------------------------------------------------------------------------
Hose inside diameter* Specimen dimensions Feeler gage dimensions
---------------------- (see fig. 4) --------------------------
------------------------
In. Mm. Depth Length Width Thickness
(inch) (inch) (inch) (inch)
------------------------------------------------------------------------
\7/32\ 5 \3/64\ 1 \1/8\ \3/64\
\1/4\ 6 \1/16\ 1 \1/8\ \1/16\
\9/32\ ......... \1/16\ 1 \1/8\ \1/16\
\11/32\ 8 \5/64\ 1 \3/16\ \5/64\
\3/8\ 10 \3/32\ 1 \3/16\ \3/32\
\7/16\ ......... \5/64\ 1 \1/4\ \5/64\
\15/32\ ......... \5/64\ 1 \1/4\ \5/64\
\1/2\ 12 \1/8\ 1 \1/4\ \1/8\
\5/8\ 16 \5/32\ 1 \1/4\ \5/32\
\3/4\ ......... \3/16\ 1 \1/4\ \3/16\
1 ......... \1/4\ 1 \1/4\ \1/4\
------------------------------------------------------------------------
*These sizes are listed to provide test values for brake hoses
manufactured in these sizes. They do not represent conversions.
(b) Apply gradually increasing force to the test specimen to
compress its inside diameter to that specified in Table VI (dimension D
of figure 4) for the size of hose tested.
[GRAPHIC] [TIFF OMITTED] TC01AU91.009
Fig. 4--Deformed Specimen of Vacuum Brake Hose
(c) After 5 seconds release the force and record the peak load
applied.
(d) Repeat the procedure four times permitting a 10-second recovery
period between load applications.
S10.10 End fitting corrosion resistance test. Conduct the test
specified in S6.9 using a vacuum brake hose assembly.
S11. Test conditions. Each hose assembly or appropriate part thereof
shall be able to meet the requirements of S5., S7., and S9. under the
following conditions.
S11.1 The temperature of the testing room is 75 [deg]F.
S11.2 Except for S6.6, S8.2, and S10.2, the test samples are
stabilized at test room temperature prior to testing.
S11.3 The brake hoses and brake hose assemblies are at least 24
hours old, and unused.
[38 FR 31303, Nov. 13, 1973]
Editorial Note: For Federal Register citations affecting Sec.
571.106, see the List of CFR Sections Affected, which appears in the
[[Page 267]]
Finding Aids section of the printed volume and on GPO Access.
Effective Date Note: At 69 FR 76321, Dec. 20, 2004, Sec. 571.106
was amended by:
a. Adding in S4 the definition of ``Preformed'' in the appropriate
alphabetical order;
b. Revising the first sentence of paragraph (b) of S5.2.2;
c. Revising the first sentence of paragraph (b) of S5.2.4;
d. Revising S5.3 through S5.3.2;
e. Revising Table I;
f. Revising S5.3.4;
g. Revising S5.3.6;
h. Revising S5.3.8 and S5.3.9;
i. Revising S5.3.11;
j. Adding S5.3.12 and S5.3.13;
k. Revising paragraph (b) of S6.1.3;
l. Revising paragraph (c) of S6.2;
m. Revising S6.4;
n. Revising S6.4.2;
o. Revising S6.5;
p. Removing S6.5.1 and S6.5.2;
q. Revising paragraphs (a) and (b) of S6.6.1;
r. Revising paragraph (b) of S6.8.2;
s. Revising S6.9;
t. Revising paragraphs (a) and (b) in S6.9.1;
u. Removing S6.9.1(c) through (f);
v. Adding Figure 3 following S6.9.1(b);
w. Revising S6.9.2;
x. Removing S6.9.3;
y. Adding S6.10 through S6.12;
z. Adding Figure 4 following S6.12.2;
aa. Revising S7.1;
bb. Revising the first sentence in paragraph (b), and paragraphs
(d), and (e) of S7.2.1;
cc. Revising Table III;
dd. Revising the first sentence in paragraph (b) and paragraph (d)
of S7.2.2;
ee. Revising S7.3, S7.3.1, S7.3.2, and S7.3.3;
ff. Revising Table IV;
gg. Revising S7.3.5 through S7.3.11;
hh. Revising paragraphs (a) and (b) of S8.1;
ii. Revising paragraphs (a) and (c) in S8.2;
jj. Adding paragraph (d) in S8.2;
kk. Revising paragraph (b) in S8.3.2;
ll. Revising S8.4;
mm. Revising the heading of S8.6;
nn. Revising S8.7;
oo. Adding S8.7.1 and S8.7.2;
pp. Adding Figure 5 and the table accompanying Figure 5, following
S8.7.1;
qq. Revising S8.8;
rr. Revising in S8.9 the introductory sentence and paragraph (a);
ss. Adding S8.13 and S8.14;
tt. Revising S9.2 and S9.2.1 through S9.2.3;
uu. Revising S9.2.7 through S9.2.10;
vv. Removing S9.2.11;
ww. Revising S10.1 and S10.2;
xx. Revising paragraph (a) of S10.6;
yy. Redesignating Figure 3 as Figure 6, following S10.6;
zz. Revising S10.7;
aaa. Removing and reserving S10.8;
bbb. Revising paragraph (b) in S10.9.2;
ccc. Redesignating Figure 4 as Figure 7, following S10.9.2(b);
ddd. Revising S10.10;
eee. Revising S11 and S11.1;
fff. Adding Table VII, following S11.1;
ggg. Revising S11.2;
hhh. Adding S11.2.1 through S11.2.3.1;
iii. Revising S11.3;
jjj. Adding S11.3.1 through S11.3.5;
kkk. Adding Table VIII, following S11.3.5;
lll. Adding S11.3.6 through S11.3.24;
mmm. Adding S12;
nnn. Adding S12.1 through S12.7;
ooo. Adding Figure 8, and the table accompanying Figure 8, following
S12.7;
ppp. Adding S12.8 through S12.25;
qqq. Adding S13; and
rrr. Adding S13.1 through S13.3, effective Dec. 20, 2006.
For the convenience of the user the added and revised text is set
forth as follows:
Sec. 571.106 Standard No. 106; Brake hoses.
* * * * *
S4. Definitions.
* * * * *
Preformed means a brake hose that is manufactured with permanent
bends and is shaped to fit a specific vehicle without further bending.
* * * * *
S5. Requirements--Hydraulic brake hose, brake hose assemblies, and
brake hose end fittings.
* * * * *
S5.2.2 * * *
* * * * *
(b) A designation that identifies the manufacturer of the hose,
which shall be filed in writing with: Office of Vehicle Safety
Compliance, Equipment Division NVS-222, National Highway Traffic Safety
Administration, 400 Seventh St. SW., Washington, DC 20590.* * *
* * * * *
S5.2.4 * * *
* * * * *
(b) A designation that identifies the manufacturer of the hose
assembly, which shall be filed in writing with: Office of Vehicle Safety
Compliance, Equipment Division NVS-222,
[[Page 268]]
National Highway Traffic Safety Administration, 400 Seventh St. SW.,
Washington, DC 20590. * * *
* * * * *
S5.3 Test requirements. A hydraulic brake hose assembly or
appropriate part thereof shall be capable of meeting any of the
requirements set forth under this heading, when tested under the
conditions of S13 and the applicable procedures of S6. However, a
particular hose assembly or appropriate part thereof need not meet
further requirements after having been subjected to and having met the
constriction requirement (S5.3.1) and any one of the requirements
specified in S5.3.2 through S5.3.13.
S5.3.1 Constriction. Except for that part of an end fitting which
does not contain hose, every inside diameter of any section of a
hydraulic brake hose assembly shall be not less than 64 percent of the
nominal inside diameter of the brake hose (S6.12).
S5.3.2 Expansion and burst strength. The maximum expansion of a
hydraulic brake hose assembly at 1,000 psi, 1,500 psi and 2,900 psi
shall not exceed the values specified in Table I (S6.1), except that a
brake hose larger than \3/16\ inch or 5 mm is not subject to the 2,900
psi expansion test requirements. The hydraulic brake hose assembly shall
then withstand water pressure of 4,000 psi for 2 minutes without
rupture, and then shall not rupture at less than 7,000 psi for a \1/8\
inch, 3 mm, or smaller diameter hose, or at less than 5,000 psi for a
hose with a diameter larger than \1/8\ inch or 3 mm (S6.2).
Table I.--Maximum Expansion of Free Length Brake Hose, CC/FT
----------------------------------------------------------------------------------------------------------------
Test pressure
-----------------------------------------------------------------------------
1,000 psi 1,500 psi 2,900 psi
Hydraulic brake hose, inside -----------------------------------------------------------------------------
diameter Regular Low Regular Low Regular Low
expansion expansion expansion expansion expansion expansion
hose hose hose hose hose hose
----------------------------------------------------------------------------------------------------------------
\1/8\ inch, or 3 mm, or less...... 0.66 0.33 0.79 0.42 1.21 0.61
\3/16\ inch, or 4 to 5 mm......... 0.86 0.55 1.02 0.72 1.67 0.91
\1/4\ inch, or 6 mm, or more...... 1.04 0.82 1.30 1.17 * *
----------------------------------------------------------------------------------------------------------------
*Not applicable.
* * * * *
S5.3.4 Tensile strength. A hydraulic brake hose assembly shall
withstand a pull of 325 pounds without separation of the hose from its
end fittings during a slow pull test, and shall withstand a pull of 370
pounds without separation of the hose from its end fittings during a
fast pull test (S6.4).
* * * * *
S5.3.6 Water absorption and tensile strength. A hydraulic brake hose
assembly, after immersion in water for 70 hours (S6.5), shall withstand
a pull of 325 pounds without separation of the hose from its end
fittings during a slow pull test, and shall withstand a pull of 370
pounds without separation of the hose from its end fittings during a
fast pull test (S6.4).
* * * * *
S5.3.8 Low-temperature resistance. A hydraulic brake hose
conditioned at a temperature between minus 49 degrees Fahrenheit (minus
45 degrees Celsius) and minus 54 degrees Fahrenheit (minus 48 degrees
Celsius) for 70 hours shall not show cracks visible without
magnification when bent around a cylinder as specified in S6.6 (S6.6).
S5.3.9 Brake fluid compatibility, constriction, and burst strength.
Except for brake hose assemblies designed for use with mineral or
petroleum-based brake fluids, a hydraulic brake hose assembly shall meet
the constriction requirement of S5.3.1 after having been subjected to a
temperature of 248 degrees Fahrenheit (120 degrees Celsius) for 70 hours
while filled with SAE RM-66-04 ``Compatibility Fluid,'' as described in
Appendix B of SAE Standard J1703, revised JAN 1995, ``Motor Vehicle
Brake Fluid.'' This incorporation by reference was approved by the
Director of the Federal Register in accordance with 5 U.S.C. 552(a) and
1 CFR Part 51. Copies may be obtained from the Society of Automotive
Engineers, Inc., 400 Commonwealth Drive, Warrendale, PA 15096-0001.
Copies may be inspected at the National Highway Traffic Safety
Administration, Technical Information Services, 400 Seventh Street, SW.,
Plaza Level, Room 403, Washington, DC 20590, or at the National Archives
and Records Administration (NARA). For information on the availability
of this material at NARA, call 202-741-6030, or go to: http://
www.archives.gov/federal--register/code--of--federal--regulations/ibr--
locations.html. It shall then withstand water pressure of 4,000 psi for
2 minutes and thereafter shall not rupture at less than 5,000
[[Page 269]]
psi (S6.2 except all sizes of hose are tested at 5,000 psi).
* * * * *
S5.3.11 Dynamic ozone test. A hydraulic brake hose shall not show
cracks visible without magnification after having been subjected to a
48-hour dynamic ozone test (S6.9).
S5.3.12 High temperature impulse test. A brake hose assembly tested
under the conditions in S6.10:
(a) Shall withstand pressure cycling for 150 cycles, at 295 degrees
Fahrenheit (146 degrees Celsius) without leakage;
(b) Shall not rupture during a 2-minute, 4,000 psi pressure hold
test, and;
(c) Shall not burst at a pressure less than 5,000 psi.
S5.3.13 End fitting corrosion resistance. After 24 hours of exposure
to salt spray, a hydraulic brake hose end fitting shall show no base
metal corrosion on the end fitting surface except where crimping or the
application of labeling information has caused displacement of the
protective coating (S6.11).
S6. Test procedures--Hydraulic brake hose, brake hose assemblies,
and brake hose end fittings.
* * * * *
S6.1.3 Calculation of expansion at 1,000 psi, 1,500 psi and 2,900
psi.
* * * * *
(b) Close the valve to the burette, apply pressure at the rate of
1,500 psi per minute, and seal 1,000 psi in the hose (1,500 in second
series, and 2,900 psi in third series).
* * * * *
S6.2 Burst strength test.
* * * * *
(c) After 2 minutes at 4,000 psi, increase the pressure at the rate
of 15,000 psi per minute until the pressure exceeds 5,000 psi for a
brake hose larger than \1/8\ inch or 3 mm diameter, or until the
pressure exceeds 7,000 psi for a brake hose of \1/8\ inch, 3 mm, or
smaller diameter.
* * * * *
S6.4 Tensile strength test. Utilize a tension testing machine
conforming to the requirements of American Society for Testing and
Materials (ASTM) E4-03, ``Standard Practices for Force Verification of
Testing Machines,'' and provided with a recording device to measure the
force applied. This incorporation by reference was approved by the
Director of the Federal Register in accordance with 5 U.S.C. 552(a) and
1 CFR Part 51. Copies may be obtained from the American Society for
Testing and Materials (ASTM) International, 100 Barr Harbor Drive, P.O.
Box C700, West Conshohocken, PA 19428-2959. Copies may be inspected at
the National Highway Traffic Safety Administration, Technical
Information Services, 400 Seventh St., S.W., Plaza Level, Room 403,
Washington, D.C. 20590, or at the National Archives and Records
Administration (NARA). For information on the availability of this
material at NARA, call 202-741-6030, or go to: http://www.archives.gov/
federal--register/code--of--federal--regulations/ibr--locations.html.
* * * * *
S6.4.2 Operation. (a) Conduct the slow pull test by applying tension
at a rate of 1 inch per minute travel of the moving head until
separation occurs.
(b) Conduct the fast pull test by applying tension at a rate of 2
inches per minute travel of the moving head until separation occurs.
* * * * *
S6.5 Water absorption sequence tests. (a) Prepare three brake hose
assemblies and measure the free length of the hose assemblies.
(b) Immerse the brake hose assemblies in distilled water at 185
degrees Fahrenheit (85 degrees Celsius) for 70 hours. Remove the brake
hose assemblies from the water and condition in air at room temperature
for 30 minutes.
(c) Conduct the tests in S6.2, S6.3, and S6.4, using a different
hose for each sequence.
S6.6 Low temperature resistance test.
S6.6.1 Preparation. (a) Remove hose armor, if any, and condition the
hose in a straight position in air at a temperature between minus 49
degrees Fahrenheit and minus 54 degrees Fahrenheit (minus 45 degrees
Celsius and minus 48 degrees Celsius) for 70 hours.
(b) Condition a cylinder in air at a temperature between minus 49
degrees Fahrenheit and minus 54 degrees Fahrenheit (minus 45 degrees
Celsius and minus 48 degrees Celsius) for 70 hours, using a cylinder of
2\1/2\ inches in diameter for tests of hose less than \1/8\ inch or 3mm,
3 inches in diameter for tests of \1/8\ inch or 3 mm hose, 3\1/2\ inches
in diameter for tests of \3/16\ to \1/4\ inch hose or 4 mm to 6 mm hose,
and 4 inches in diameter for tests of hose greater than \1/4\ inch or 6
mm in diameter.
* * * * *
[[Page 270]]
S6.8.2 Exposure to ozone.
* * * * *
(b) Immediately thereafter, condition the hose on the cylinder for
70 hours in an exposure chamber having an ambient air temperature of 104
degrees Fahrenheit (40 degrees Celsius) during the test and containing
air mixed with ozone in the proportion of 100 parts of ozone per 100
million parts of air by volume.
* * * * *
S6.9 Dynamic ozone test.
S6.9.1 Apparatus. Utilize a test apparatus shown in Figure 3 which
is constructed so that:
(a) It has a fixed pin with a vertical orientation over which one
end of the brake hose is installed.
(b) It has a movable pin that is oriented 30 degrees from vertical,
with the top of the movable pin angled towards the fixed pin. The
moveable pin maintains its orientation to the fixed pin throughout its
travel in the horizontal plane. The other end of the brake hose is
installed on the movable pin.
[GRAPHIC] [TIFF OMITTED] TR20DE04.004
S6.9.2 Preparation. (a) Precondition the hose assembly by laying it
on a flat surface in an unstressed condition, at room temperature, for
24 hours.
(b) Cut the brake hose assembly to a length of 8.6 inches (218 mm),
such that no end fittings remain on the cut hose.
(c) Mount the brake hose onto the test fixture by fully inserting
the fixture pins into each end of the hose. Secure the hose to the
fixture pins using a band clamp at each end of the hose.
(d) Place the test fixture into an ozone chamber
(e) Stabilize the atmosphere in the ozone chamber so that the
ambient temperature is 104 [deg]F (40 degrees Celsius) and the air
mixture contains air mixed with ozone in the
[[Page 271]]
proportion of 100 parts of ozone per 100 million parts of air by volume.
This atmosphere is to remain stable throughout the remainder of the
test.
(f) Begin cycling the movable pin at a rate of 0.3 Hz. Continue the
cycling for 48 hours.
(g) At the completion of 48 hours of cycling, remove the test
fixture from the ozone chamber. Without removing the hose from the test
fixture, visually examine the hose for cracks without magnification,
ignoring areas immediately adjacent to or within the area covered by the
band clamps. Examine the hose with the movable pin at any point along
its travel.
S6.10 High temperature impulse test.
S6.10.1 Apparatus. (a) A pressure cycling machine to which one end
of the brake hose assembly can be attached, with the entire hose
assembly installed vertically inside of a circulating air oven. The
machine shall be capable of increasing the pressure in the hose from
zero psi to 1600 psi, and decreasing the pressure in the hose from 1600
psi to zero psi, within 2 seconds.
(b) A circulating air oven that can reach a temperature of 295
degrees Fahrenheit (146 degrees Celsius) within 30 minutes, and that can
maintain a constant 295 degrees F (146 degrees Celsius) thereafter, with
the brake hose assembly inside of the oven and attached to the pressure
cycling machine.
(c) A burst test apparatus to conduct testing specified in S6.2
S6.10.2 Preparation. (a) Connect one end of the hose assembly to the
pressure cycling machine and plug the other end of the hose. Fill the
pressure cycling machine and hose assembly with SAE RM-66-04
``Compatibility Fluid,'' as described in Appendix B of SAE Standard
J1703, revised JAN 1995 ``Motor Vehicle Brake Fluid,'' and bleed all
gases from the system.
(b) Place the brake hose assembly inside of the circulating air oven
in a vertical position. Increase the oven temperature to 295 degrees F
(146 degrees Celsius) and maintain this temperature throughout the
pressure cycling test.
(c) During each pressure cycle, the pressure in the hose is
increased from zero psi to 1600 psi and held constant for 1 minute, then
the pressure is decreased from 1600 psi to zero psi and held constant
for 1 minute. Perform 150 pressure cycles on the brake hose assembly.
(d) Remove the brake hose assembly from the oven, disconnect it from
the pressure cycling machine, and drain the fluid from the hose. Cool
the brake hose assembly at room temperature for 45 minutes.
(e) Wipe the brake hose using acetone to remove residual
Compatibility Fluid. Conduct the burst strength test in S6.2, except all
sizes of hose are tested at 5,000 psi.
S6.11 End fitting corrosion test. Utilize the apparatus described in
ASTM B117-03, ``Standard Practice for Operating Salt Spray (Fog)
Apparatus''. This incorporation by reference was approved by the
Director of the Federal Register in accordance with 5 U.S.C. 552(a) and
1 CFR Part 51. Copies may be obtained from the American Society for
Testing and Materials (ASTM) International, 100 Barr Harbor Drive, P.O.
Box C700, West Conshohocken, PA 19428-2959. Copies may be inspected at
the National Highway Traffic Safety Administration, Technical
Information Services, 400 Seventh St., SW., Plaza Level, Room 403,
Washington, DC 20590, or at the National Archives and Records
Administration (NARA). For information on the availability of this
material at NARA, call (202) 741-6030, or go to: http://
www.archives.gov/federal--register/code--of--federal--regulations/ibr--
locations.html.
S6.11.1 Construction. Construct the salt spray chamber so that:
(a) The construction material does not affect the corrosiveness of
the fog.
(b) The hose assembly is supported or suspended 30 degrees from the
vertical and parallel to the principal direction of the horizontal flow
of fog through the chamber.
(c) The hose assembly does not contact any metallic material or any
material capable of acting as a wick
(d) Condensation which falls from the assembly does not return to
the solution reservoir for respraying.
(e) Condensation from any source does not fall on the brake hose
assemblies or the solution collectors.
(f) Spray from the nozzles is not directed onto the hose assembly.
S6.11.2 Preparation. (a) Plug each end of the hose assembly.
(b) Mix a salt solution five parts by weight of sodium chloride to
95 parts of distilled water, using sodium chloride substantially free of
nickel and copper, and containing on a dry basis not more than 0.1
percent of sodium iodide and not more than 0.3 percent total impurities.
Ensure that the solution is free of suspended solids before the solution
is atomized.
(c) After atomization at 95 degrees Fahrenheit (35 degrees Celsius),
ensure that the collected solution is in the PH range of 6.5 to 7.2.
Make the PH measurements at 77 degrees Fahrenheit (28 degrees Celsius).
(d) Maintain a compressed air supply to the nozzle or nozzles free
of oil and dirt and between 10 and 25 psi.
S6.11.3 Operation. Subject the brake hose assembly to the salt spray
continuously for 24 hours.
(a) Regulate the mixture so that each collector will collect from 1
to 2 milliliters of solution per hour for each 80 square centimeters of
horizontal collecting area.
(b) Maintain exposure zone temperature at 95 degrees Fahrenheit (35
degrees Celsius).
[[Page 272]]
(c) Upon completion, remove the salt deposit from the surface of the
hose by washing gently or dipping in clean running water not warmer than
100 degrees Fahrenheit (38 degrees Celsius) and then drying immediately.
S6.12 Constriction test. Brake hose constriction test requirements
shall be met using at least one of the methods specified in S6.12.1,
S6.12.2, or S6.12.3.
S6.12.1 Plug gauge. (a) Utilize a plug gauge as shown in Figure 4.
Diameter ``A'' is equal to 64 percent of the nominal inside diameter of
the hydraulic brake hose being tested.
(b) Brake hose assemblies that are to be used for additional testing
have constriction testing only at each end fitting. Other brake hose
assemblies may be cut into 3-inch lengths to permit constriction testing
of the entire assembly. Hose assemblies with end fittings that do not
permit entry of the gauge (e.g., restrictive orifice or banjo fitting)
are cut 3 inches from the point at which the hose terminates in the end
fitting and then tested from the cut end.
(c) Hold the brake hose in a straight position and vertical
orientation.
(d) Place the spherical end of the plug gauge just inside the hose
or end fitting. If the spherical end will not enter the hose or end
fitting using no more force than gravity acting on the plug gauge, this
constitutes failure of the constriction test.
(e) Release the plug gauge. Within 3 seconds, the plug gauge shall
fall under the force of gravity alone up to the handle of the gauge. If
the plug gauge does not fully enter the hose up to the handle of the
gauge within three seconds, this constitutes failure of the constriction
test.
S6.12.2 Extended plug gauge. (a) The test in 6.12.1 may be conducted
with an extended plug gauge to enable testing of the entire brake hose
from one end fitting, without cutting the brake hose. The extended plug
gauge weight and spherical diameter specifications are as shown in
Figure 4, but the handle portion of the gauge may be deleted and the
gauge length may be greater than 3 inches.
(b) The required performance of the extended plug gauge in
S6.12.1(e) is that after the plug gauge is released, the extended plug
gauge shall fall under the force of gravity alone at an average rate of
1 inch per second until the spherical diameter of the extended gauge
passes through all portions of the brake hose assembly containing hose.
If the extended plug gauge does not pass through all portions of the
brake hose assembly containing hose at an average rate of 1 inch per
second, this constitutes failure of the constriction test.
[GRAPHIC] [TIFF OMITTED] TR20DE04.005
S6.12.3 Drop ball test. (a) Utilize a rigid spherical ball with a
diameter equal to 64 percent of the nominal inside diameter of the
hydraulic brake hose being tested. The weight of the spherical ball
shall not exceed 2 ounces (57 grams).
[[Page 273]]
(b) Hold the brake hose in a straight position and vertical
orientation.
(c) Hold the ball just above the end fitting.
(d) Release the ball. The ball shall fall under the force of gravity
alone completely through all portions of the brake hose assembly
containing hose, at an average rate of 1 inch per second. Failure of the
ball to pass completely through all portions of the brake hose assembly
containing hose, at an average rate of 1 inch per second, constitutes
failure of the constriction test.
* * * * *
S7.1 Construction. Each air brake hose assembly shall be equipped
with permanently attached brake hose end fittings or reusable brake hose
end fittings. Each air brake hose constructed of synthetic or natural
elastomeric rubber shall conform to the dimensional requirements
specified in Table III, except for brake hose manufactured in metric
sizes.
* * * * *
S7.2.1 Hose. * * *
* * * * *
(b) A designation that identifies the manufacturer of the hose,
which shall be filed in writing with: Office of Vehicle Safety
Compliance, Equipment Division NVS-222, National Highway Traffic Safety
Administration, 400 Seventh St. SW., Washington, DC 20590.* * *
* * * * *
(d) The nominal inside diameter of the hose expressed in inches or
fractions of inches or in millimeters. The abbreviation ``mm'' shall
follow hose sizes that are expressed in millimeters. (Examples: \3/8\,
\1/2\ (\1/2\SP in the case of \1/2\ inch special air brake hose), 4mm,
6mm.)
(e) The type designation corresponding to the brake hose dimensions
in Table III. Type A shall be labeled with the letter ``A'', Type AI
shall be labeled with the letters ``AI'', and type AII shall be labeled
with the letters ``AII''. Metric air brake hose shall be labeled with
the letter ``A.''
Table III.--Air Brake Hose Dimensions. Inside Diameter (ID) and Outside Diameter (OD) Dimensions in Inches
(Millimeters)
----------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------
TYPE A--HOSE SIZE--NOMINAL INSIDE DIAMETER
----------------------------------------------------------------------------------------------------------------
\1/4\ \5/16\ \3/ \7/ \1/2\ \5/8\
8\\(1)\ 16\\(1)\ SP\(1)\
-----------------------------------------------
Min........................................... 0.277 0.289 0.352 0.407 0.469 0.594
I.D........................................... (5.8) (7.3) (8.9) (10.3) (11.9) (15.1)
Max........................................... 0.273 0.335 0.398 0.469 0.531 0.656
I.D........................................... (6.9) (8.5) (10.1) (11.9) (13.5) (16.7)
Min........................................... 0.594 0.656 0.719 0.781 0.844 1.031
O.D........................................... (15.1) (16.7) (18.3) (19.8) (21.4) (26.2)
Max........................................... 0.656 0.719 0.781 0.843 0.906 1.094
O.D........................................... (16.7) (18.3) (19.8) (21.4) (23.0) (27.8)
-----------------------------------------------
TYPE AI\(2)\--HOSE SIZE--NOMINAL INSIDE DIAMETER
----------------------------------------------------------------------------------------------------------------
\3/16\ \1/4\ \5/16\ \13/32\ \1/2\ \5/8\
-----------------------------------------------
Min........................................... 0.188 0.250 0.312 0.406 0.500 0.625
I.D........................................... (4.8) (6.4) (7.9) (10.3) (12.7) (15.9)
Max........................................... 0.214 0.281 0.343 0.437 0.539 0.667
I.D........................................... (5.4) (7.1) (8.7) (11.1) (13.7) (16.9)
Min........................................... 0.472 0.535 0.598 0.714 0.808 0.933
O.D........................................... (12.0) (13.6) (15.1) (18.1) (20.5) (23.7)
Max........................................... 0.510 0.573 0.636 0.760 0.854 0.979
O.D........................................... (13.0) (14.6) (16.2) (19.3) (21.7) (24.9)
-----------------------------------------------
[[Page 274]]
TYPE AII\(2)\--HOSE SIZE--NOMINAL INSIDE DIAMETER
----------------------------------------------------------------------------------------------------------------
\3/16\ \1/4\ \5/16\ \13/32\ \1/2\ \5/8\
-----------------------------------------------
Min........................................... 0.188 0.250 0.312 0.406 0.500 0.625
I.D........................................... (4.8) (6.4) (7.9) (10.3) (12.7) (15.9)
Max........................................... 0.214 0.281 0.343 0.437 0.539 0.667
I.D........................................... (5.4) (7.1) (8.7) (11.1) (13.7) (16.9)
Min........................................... 0.500 0.562 0.656 0.742 0.898 1.054
O.D........................................... (12.7) (14.3) (16.7) (18.8) (22.8) (26.8)
Max........................................... 0.539 0.602 0.695 0.789 0.945 1.101
O.D........................................... (13.7) (15.3) (17.7) (20.1) (24.0) (27.9)
----------------------------------------------------------------------------------------------------------------
Notes:
\(1)\ Type A, sizes \3/8\, \7/16\, and \1/2\ Special can be assembled with reusable end fittings. All sizes can
be assembled using permanently-attached (crimped) end fittings.
\(2)\ Types AI and AII, all sizes, can be assembled with reusable or permanently-attached (crimped) end
fittings.
S7.2.2 End fittings. * * *
* * * * *
(b) A designation that identifies the manufacturer of that component
of the fitting, which shall be filed in writing with: Office of Vehicle
Safety Compliance, Equipment Division NVS-222, National Highway Traffic
Safety Administration, 400 Seventh St. S.W., Washington, DC 20590. * * *
* * * * *
(d) The nominal inside diameter of the hose to which the fitting is
properly attached expressed in inches or fractions of inches or in
millimeters. (See examples in S7.2.1 (d).) The abbreviation ``mm'' shall
follow hose sizes that are expressed in millimeters.
* * * * *
S7.3 Test requirements. Each air brake hose assembly or appropriate
part thereof shall be capable of meeting any of the requirements set
forth under this heading, when tested under the conditions of S13 and
the applicable procedures of S8. However, a particular hose assembly or
appropriate part thereof need not meet further requirements after having
met the constriction requirement (S7.3.1) and then having been subjected
to any one of the requirements specified in S7.3.2 through S7.3.14.
S7.3.1 Constriction. Every inside diameter of any section of an air
brake hose assembly shall not be less than 66 percent of the nominal
inside diameter of the brake hose. (S8.14)
S7.3.2 High temperature resistance. An air brake hose shall not show
external or internal cracks, charring, or disintegration visible without
magnification when straightened after being bent for 70 hours at 212
degrees Fahrenheit (100 degrees Celsius) over a small test cylinder
having the radius specified in Table IV for the size of hose tested.
(S8.1)
S7.3.3 Low temperature resistance. The inside and outside surfaces
of an air brake hose shall not show cracks as a result of conditioning
at minus 40 degrees Fahrenheit (minus 40 degrees Celsius) for 70 hours
when bent around a large test cylinder having the radius specified in
Table IV for the size of hose tested (S8.2).
Table IV.--Air Brake Hose Diameters and Test Cylinder Radii
----------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------
Nominal hose inside diameter, inches\1\... \3/16\ \1/4\ \5/16\ \3/8\ \13/32\ \7/16\, \5/8\
\1/2\
Nominal hose inside diameter, 4, 5 6 8 ........ 10 12 16
millimeters\1\...........................
[[Page 275]]
Small test cylinder, radius in inches 1 (25) 1\1/2\ 1\3/4\ 1\3/4\ 1\7/8\ 2 (51) 2\1/2\
(millimeters)\2\......................... (38) (45) (45) (48) (64)
Large test cylinder, radius in inches 2 (51) 2\1/2\ 3 (76) 3\1/2\ 3\1/2\ 4 (102) 4\1/2\
(millimeters)\3\......................... (64) (89) (89) (114)
----------------------------------------------------------------------------------------------------------------
Notes:
\1\ These sizes are listed to provide test cylinder radii for brake hoses manufactured in these sizes. They do
not represent conversions.
\2\ Small test cylinders are used for the high temperature resistance test.
\3\ Large test cylinders are used for the low temperature resistance, ozone resistance, and adhesion of wire-
reinforced hose tests.
* * * * *
S7.3.5 Ozone resistance. An air brake hose assembly shall not show
cracks visible under 7-power magnification after exposure to ozone for
70 hours at 104 degrees Fahrenheit (49 degrees Celsius) when bent around
a test cylinder of the radius specified in Table IV for the size of hose
tested (S8.4).
S7.3.6 Length change. An air brake hose shall not contract in length
more than 7 percent nor elongate more than 5 percent when subjected to
air pressure of 200 psi (S8.5).
S7.3.7 Adhesion. (a) Except for hose reinforced by wire, an air
brake hose shall withstand a tensile force of 8 pounds per inch of
length before separation of adjacent layers (S8.6).
(b) An air brake hose reinforced by wire shall permit a steel ball
to roll freely along the entire length of the inside of the hose when
the hose is subjected to a vacuum of 25 inches of Hg and bent around a
test cylinder (S8.13).
S7.3.8 Flex strength and air pressure leakage. An air brake hose
assembly of the length specified in the table accompanying Figure 5,
when subjected to a flex test and internal pressure cycling, shall be
capable of having its internal pressure increased from zero to 140 psi
within 2 minutes with pressurized air supplied through an orifice
(S8.7).
S7.3.9 Corrosion resistance and burst strength. An air brake hose
assembly exposed to salt spray shall not rupture when exposed to
hydrostatic pressure of 900 psi (S8.8).
S7.3.10 Tensile strength. An air brake hose assembly designed for
use between a frame and axle or between a towed and towing vehicle shall
withstand, without separation of the hose from its end fittings, a pull
of 250 pounds if it is \1/4\ inch, 6 mm, or less in nominal inside
diameter, or a pull of 325 pounds if it is larger than \1/4\ inch or 6
mm in nominal inside diameter. An air brake hose assembly designed for
use in any other application shall withstand, without separation of the
hose from its end fittings, a pull of 50 pounds if it is \1/4\ inch, 6
mm, or less in nominal inside diameter, 150 pounds if it is larger than
\1/4\ inch or 6 mm and equal to or smaller than \1/2\ inch or 12 mm in
nominal inside diameter, or 325 pounds if it is larger than \1/2\ inch
or 12 mm in nominal inside diameter (S8.9).
S7.3.11 Water absorption and tensile strength. After immersion in
distilled water for 70 hours, an air brake hose assembly designed for
use between a frame and axle or between a towed and a towing vehicle
shall withstand, without separation of the hose from its end fittings, a
pull of 250 pounds if it is \1/4\ inch or less or 6 mm or less in
nominal inside diameter, or a pull of 325 pounds if it is larger than
\1/4\ inch or 6 mm in nominal inside diameter. After immersion in
distilled water for 70 hours, an air brake hose assembly designed for
use in any other application shall withstand, without separation of the
hose from its end fittings, a pull of 50 pounds if it is \1/4\ inch or 6
mm or less in nominal inside diameter, 150 pounds if it is larger than
\1/4\ inch or 6 mm and equal to or smaller than \1/2\ inch or 12 mm in
nominal inside diameter, or 325 pounds if it is larger than \1/2\ inch
or 12 mm in nominal inside diameter. (S8.10)
* * * * *
S8.1 High temperature resistance test.
(a) Utilize a small test cylinder with a radius specified in Table
IV for the size of hose tested.
(b) Bind the hose around the cylinder and condition it in an air
oven for 70 hours at 212 degrees Fahrenheit (100 degrees Celsius).
* * * * *
S8.2 Low temperature resistance test. (a) Utilize a large test
cylinder with a radius specified in Table IV for the size of hose
tested.
* * * * *
[[Page 276]]
(c) With the hose and cylinder at minus 40 degrees Fahrenheit (minus
40 degrees Celsius), bend the hose 180 degrees around the cylinder at a
steady rate in a period of 3 to 5 seconds. Remove the hose from the test
cylinder and visibly examine the exterior of the hose for cracks without
magnification.
(d) Allow the hose to warm at room temperature for 2 hours. All
reusable end fittings are removed from the hose. All permanently-
attached end fittings are cut away from the hose. Cut through one wall
of the hose longitudinally along its entire length. Unfold the hose to
permit examination of the interior surface. Visibly examine the interior
of the hose for cracks without magnification.
* * * * *
S8.3.2 Measurement.
* * * * *
(b) Immerse each specimen in ASTM IRM 903 oil for 70 hours at 212
degrees Fahrenheit (100 degrees Celsius) and then cool in ASTM IRM 903
oil at room temperature for 30 to 60 minutes.
* * * * *
S8.4 Ozone resistance test. Conduct the test specified in S6.8,
using air brake hose, except use the large test cylinder specified in
Table IV for the size of hose tested.
* * * * *
S8.6 Adhesion test for air brake hose not reinforced by wire.
* * * * *
S8.7 Flex strength and air pressure test.
S8.7.1 Apparatus. A flex testing machine with a fixed hose assembly
attachment point and a movable hose assembly attachment point, which
meets the dimensional requirements of Figure 5 for the size of hose
being tested. The attachment points connect to the end fittings on the
hose assembly without leakage and, after the hose assembly has been
installed for the flex test, are restrained from rotation. The movable
end has a linear travel of 6 inches and a cycle rate of 100 cycles per
minute. The machine is capable of increasing the air pressure in the
hose assembly from zero to 150 psi within 2 seconds, and decreasing the
air pressure in the hose assembly from 150 to zero psi within 2 seconds.
[GRAPHIC] [TIFF OMITTED] TR20DE04.006
[[Page 277]]
Table Accompanying Figure 5.--Dimensions in Inches (Millimeters)
----------------------------------------------------------------------------------------------------------------
Dimensions
---------------------------------------------------------------
Free hose length Nominal hose Position ``1'' Position ``2''
inside diameter ---------------------------------------------------------------
A B C R (1) A B C R (1)
----------------------------------------------------------------------------------------------------------------
10.00 (254)................... \3/16\, \1/4\... 3.00 2.75 3.75 1.40 3.00 2.75 3.75 1.20
(76) (70) (95) (34) (76) (70) (95) (30)
11.00 (279)................... \5/16\, \3/8\, 3.00 3.50 4.50 1.70 3.00 3.50 4.50 1.30
\13/32\. (76) (89) (114) (43) (76) (89) (114) (33)
14.00 (355)................... \7/16\, \1/2\, 3.00 4.00 5.00 2.20 3.00 4.00 5.00 1.80
\5/8\. (76) (102) (127) (56) (76) (102) (102) (46)
----------------------------------------------------------------------------------------------------------------
Note (1) This is an approximate average radius.
S8.7.2 Preparation. (a) Lay the hose material on a flat surface in
an unstressed condition. Apply a permanent marking line along the
centerline of the hose on the uppermost surface.
(b) Prepare the hose assembly with a free length as shown in the
table accompanying Figure 5. The end fittings shall be attached
according to the end fitting manufacturer's instructions.
(c) Plug the ends of the hose assembly and conduct the salt spray
test in S6.11 using an air brake hose assembly. Remove the plugs from
the end fittings.
(d) Within 168 hours of completion of the salt spray test, expose
the hose assembly to an air temperature of 212 degrees Fahrenheit (100
degrees Celsius) for 70 hours, with the hose in a straight position.
Remove the hose and cool it at room temperature for 2 hours. Within 166
hours, subject the hose to the flexure test in S8.7.2(e).
(e) Install the hose assembly on the flex testing machine as
follows. With the movable hose attachment point at the mid point of its
travel, attach one end of the hose to the movable attachment point with
the marked line on the hose in the uppermost position. Attach the other
end of the hose to the fixed attachment point allowing the hose to
follow its natural curvature.
(f) Cycle the air pressure in the hose by increasing the pressure in
the hose from zero psi to 150 psi and holding constant for one minute,
then decreasing the pressure from 150 psi to zero psi and holding
constant for one minute. Continue the pressure cycling for the duration
of the flex testing. Begin the flex testing by cycling the movable
attachment point through 6 inches of travel at a rate of 100 cycles per
minute. Stop the flex testing and pressure cycling after one million
flex cycles have been completed.
(g) Install an orifice with a hole diameter of 0.0625 inches and a
thickness of 0.032 inches in the air pressure supply line to the hose
assembly. Provide a gauge or other means to measure air pressure in the
hose assembly. Regulate the supply air pressure to the orifice to 150
psi.
(h) Apply 150 psi air pressure to the orifice. After 2 minutes have
elapsed, measure the air pressure in the brake hose assembly, while
pressurized air continues to be supplied through the orifice.
S8.8 Corrosion resistance and burst strength test. (a) Conduct the
test specified in S6.11 using an air brake hose assembly. Remove the
plugs from the ends of the hose assembly.
(b) Fill the hose assembly with water, allowing all gases to escape.
Apply water pressure at a uniform rate of increase of approximately
1,000 psi per minute until the hose ruptures.
S8.9 Tensile strength test. Utilize a tension testing machine
conforming to the requirements of American Society for Testing and
Materials (ASTM) E4-03 ``Standard Practices for Force Verification of
Testing Machines,'' and provided with a recording device to measure the
force applied.
(a) Attach an air brake hose assembly to the testing machine to
permit straight, even, machine pull on the hose. Use adapters to mount
hose assemblies equipped with angled end fittings so that the hose is in
a straight position when installed on the machine.
* * * * *
S8.13 Adhesion test for air brake hose reinforced by wire. (a) Place
a steel ball with a diameter equal to 73 percent of the nominal inside
diameter of the hose being tested inside of the hose. Plug one end of
the hose. Attach the other end of the hose to a source of vacuum.
(b) Subject the hose to a vacuum of 25 inches of Hg for five
minutes. With the vacuum still applied to the hose, bend the hose 180
degrees around a large test cylinder with a radius specified in Table IV
for the size of hose tested. At the location of this bend, bend the hose
180 degrees around the test cylinder in the opposite direction.
(c) With the vacuum still applied to the hose, return the hose to a
straight position. Attempt to roll the ball inside the hose using
gravity from one end of the hose to the other end.
[[Page 278]]
S8.14 Constriction test. Perform the constriction test in S6.12
using an air brake hose, except that the spherical diameter ``A'' of the
plug gauge in Figure 4, or the diameter of the rigid spherical ball in
S6.12.3(a), shall be 66 percent of the nominal inside diameter of the
air brake hose being tested.
* * * * *
S9.2 Test requirements. Each vacuum brake hose assembly or
appropriate part thereof shall be capable of meeting any of the
requirements set forth under this heading, when tested under the
conditions of S13 and the applicable procedures of S10. However, a
particular hose assembly or appropriate part thereof need not meet
further requirements after having met the constriction requirement
(S9.2.1) and then having been subjected to any one of the requirements
specified in S9.2.2 through S9.2.10.
S9.2.1 Constriction. Except for that part of an end fitting which
does not contain hose, every inside diameter of any section of a vacuum
brake hose assembly shall be not less than 75 percent of the nominal
inside diameter of the hose if for heavy duty, or 70 percent of the
nominal inside diameter of hose if for light duty (S10.10).
S9.2.2 High temperature resistance. A vacuum brake hose tested under
the conditions specified in S10.1:
(a) Shall not have collapse of the outside diameter exceeding 10
percent of the initial outside diameter for a heavy-duty vacuum brake
hose, or exceeding 15 percent of the initial outside diameter for a
light-duty vacuum brake hose;
(b) Shall not show external cracks, charring, or disintegration
visible without magnification, and;
(c) Shall not leak when subjected to a hydrostatic pressure test.
S9.2.3 Low temperature resistance. A vacuum brake hose tested under
the conditions specified in S10.2 shall:
(a) Not show cracks visible without magnification after conditioning
at minus 40 degrees Fahrenheit (minus 40 degrees Celsius) for 70 hours
when bent around a cylinder having the radius specified in Table V for
the size hose tested; and
(b) Not leak when subjected to a hydrostatic pressure test (S10.6).
* * * * *
S9.2.7 Bend. The collapse of the outside diameter of a vacuum brake
hose, other than a preformed vacuum brake hose, at the middle point of
the test length when bent until the ends touch shall not exceed the
values given in Table V for the size of hose tested (S10.6).
S9.2.8 Swell and adhesion. Following exposure to Reference Fuel B,
every inside diameter of any section of a vacuum brake hose shall not be
less than 75 percent of the nominal inside diameter of the hose if for
heavy duty, or 70 percent of the nominal inside diameter of the hose if
for light duty. The vacuum brake hose shall show no leakage in a vacuum
test of 26 inches of Hg for 10 minutes. A vacuum hose that is
constructed of two or more layers shall withstand a force of 6 pounds
per inch of length before separation of adjacent layers. (S10.7).
S9.2.9 Deformation. A vacuum brake hose shall return to 90 percent
of its original outside diameter within 60 seconds after five
applications of force as specified in S10.8, except that a wire-
reinforced hose need only return to 85 percent of its original outside
diameter. In the case of a heavy duty hose, the first application of
force shall not exceed a peak value of 70 pounds, and the fifth
application of force shall reach a peak value of at least 40 pounds. In
the case of light duty hose the first application of force shall not
exceed a peak value of 50 pounds, and the fifth application of force
shall reach a peak value of at least 20 pounds (S10.9).
S9.2.10 End fitting corrosion resistance. After 24 hours of exposure
to salt spray, vacuum brake hose end fittings shall show no base metal
corrosion of the end fitting surface except where crimping or the
application of labeling information has caused displacement of the
protective coating. (S10.10).
* * * * *
S10. Test procedures--Vacuum brake hose, brake hose assemblies, and
brake hose end fittings.
S10.1 High temperature resistance test. (a) Measure the initial
outside diameter of the hose.
(b) Subject the hose to an internal vacuum of 26 inches of Hg at an
ambient temperature of 257 degrees Fahrenheit (125 degrees Celsius) for
a period of 96 hours. Remove the hose to room temperature and
atmospheric pressure.
(c) Within 5 minutes of completion of the conditioning in S10.1(b),
measure the outside diameter at the point of greatest collapse and
calculate the percentage collapse based on the initial outside diameter.
(d) Cool the hose at room temperature for 5 hours. Bend the hose
around a mandrel with a diameter equal to five times the initial outside
diameter of the hose. Examine the exterior of the hose for cracks,
charring, or disintegration visible without magnification. Remove the
hose from the mandrel.
(e) Fill the hose assembly with water, allowing all gases to escape.
Apply water pressure in the hose of 175 psi within 10 seconds. Maintain
an internal hydrostatic pressure of 175 psi for one minute and examine
the hose for visible leakage.
[[Page 279]]
S10.2 Low temperature resistance test. (a) Conduct the test
specified in S8.2(a) through (c) using vacuum brake hose with the
cylinder radius specified in Table V for the size of hose tested.
(b) Remove the hose from the test cylinder, warm the hose at room
temperature for 5 hours, and conduct the hydrostatic pressure test in
S10.1(e).
* * * * *
S10.6 Bend test. (a) Bend a vacuum brake hose, of the length
prescribed in Table V, in the direction of its normal curvature until
the ends just touch as shown in Figure 6.
* * * * *
S10.7 Swell and adhesion test. (a) Fill a specimen of vacuum brake
hose 12 inches long with ASTM Reference Fuel B as described in ASTM
D471-98 [egr]\1\ Standard Test Method for Rubber Property--
Effect of Liquids. This incorporation by reference was approved by the
Director of the Federal Register in accordance with 5 U.S.C. 552(a) and
1 CFR part 51. Copies may be obtained from the American Society for
Testing and Materials (ASTM) International, 100 Barr Harbor Drive, P.O.
Box C700, West Conshohocken, PA 19428-2959. Copies may be inspected at
the National Highway Traffic Safety Administration, Technical
Information Services, 400 Seventh St., SW., Plaza Level, Room 403,
Washington, DC 20590, or at the National Archives and Records
Administration (NARA). For information on the availability of this
material at NARA, call 202-741-6030, or go to: http://www.archives.gov/
federal--register/code--of--federal--regulations/ibr--locations.html.
(b) Maintain reference fuel in the hose under atmospheric pressure
at room temperature for 48 hours.
(c) Remove fuel and conduct the constriction test in S10.10.
(d) Attach the hose to a source of vacuum and subject it to a vacuum
of 26 inches of Hg for 10 minutes. Remove the hose from the vacuum
source.
(e) For a vacuum brake hose constructed of two or more layers,
conduct the test specified in S8.6 using the vacuum brake hose.
S10.8 [Reserved]
* * * * *
S10.9.2 Operation.
* * * * *
(b) Apply gradually increasing force to the test specimen to
compress its inside diameter to that specified in Table VI (dimension D
of Figure 7) for the size of hose tested.
* * * * *
S10.10 Constriction test. Perform the constriction test in S6.12
using a vacuum brake hose, except that the spherical diameter ``A'' of
the plug gauge in Figure 4, or the diameter of the rigid spherical ball
in S6.12.3(a), shall be 75 percent of the nominal inside diameter of the
vacuum brake hose if it is heavy duty, or 70 percent of the nominal
inside diameter of the vacuum brake hose if it is light duty.
S11. Requirements--Plastic air brake tubing, plastic air brake
tubing assemblies, and plastic air brake tubing end fittings.
11.1 Construction. Each plastic air brake tubing assembly shall be
equipped with permanently attached end fittings or reusable end
fittings. Plastic air brake tubing shall conform to the dimensional
requirements specified in Table VII. (S12.1)
Table VII.--Plastic Air Brake Tubing Dimensions
--------------------------------------------------------------------------------------------------------------------------------------------------------
Maximum outside Minimum outside Nominal inside Nominal wall Wall thickness
diameter diameter diameter thickness tolerance
Nominal tubing outside diameter -----------------------------------------------------------------------------------------
mm inches mm inches mm inches mm inches mm inches
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1/8\ inch.................................................... 3.25 0.128 3.10 0.122 2.01 0.079 0.58 0.023 0.08 0.003
\5/32\ inch................................................... 4.04 0.159 3.89 0.153 2.34 0.092 0.81 0.032 0.08 0.003
\3/16\ inch................................................... 4.83 0.190 4.67 0.184 2.97 0.117 0.89 0.035 0.08 0.003
\1/4\ inch.................................................... 6.43 0.253 6.27 0.247 4.32 0.170 1.02 0.040 0.08 0.003
\5/16\ inch................................................... 8.03 0.316 7.82 0.308 5.89 0.232 1.02 0.040 0.10 0.004
\3/8\ inch.................................................... 9.63 0.379 9.42 0.371 6.38 0.251 1.57 0.062 0.10 0.004
\1/2\ inch.................................................... 12.83 0.505 12.57 0.495 9.55 0.376 1.57 0.062 0.10 0.004
\5/8\ inch.................................................... 16.00 0.630 15.75 0.620 11.20 0.441 2.34 0.092 0.13 0.005
\3/4\ inch.................................................... 19.18 0.755 18.92 0.745 14.38 0.566 2.34 0.092 0.13 0.005
6 mm.......................................................... 6.10 0.240 5.90 0.232 4.00 0.157 1.00 0.039 0.10 0.004
8 mm.......................................................... 8.10 0.319 7.90 0.311 6.00 0.236 1.00 0.039 0.10 0.004
10 mm......................................................... 10.13 0.399 9.87 0.389 7.00 0.276 1.50 0.059 0.10 0.004
12 mm......................................................... 12.13 0.478 11.87 0.467 9.00 0.354 1.50 0.059 0.10 0.004
16 mm......................................................... 16.13 0.635 15.87 0.625 12.00 0.472 2.00 0.079 0.13 0.005
--------------------------------------------------------------------------------------------------------------------------------------------------------
[[Page 280]]
S11.2 Labeling.
S11.2.1 Plastic air brake tubing. Plastic air brake tubing shall be
labeled, or cut from bulk tubing that is labeled, at intervals of not
more than 6 inches, measured from the end of one legend to the beginning
of the next, in block capital letters and numerals at least one-eighth
of an inch high, with the information listed in paragraphs (a) through
(e) of this section. The information need not be present on tubing that
is sold as part of a motor vehicle.
(a) The symbol DOT, constituting a certification by the hose
manufacturer that the hose conforms to all applicable motor vehicle
safety standards.
(b) A designation that identifies the manufacturer of the tubing,
which shall be filed in writing with: Office of Vehicle Safety
Compliance, Equipment Division NVS-222, National Highway Traffic Safety
Administration, 400 Seventh St. SW., Washington, DC 20590. The
designation may consist of block capital letters, numerals, or a symbol.
(c) The month, day, and year, or the month and year, of manufacture,
expressed in numerals. For example, 10/1/96 means October 1, 1996.
(d) The nominal outside diameter expressed in inches or fractions of
inches or in millimeters followed by the letters OD. The abbreviation
``mm'' shall follow tubing sizes that are expressed in millimeters.
(Examples: \3/8\ OD, 6 mm OD.)
(e) The letter ``A'' shall indicate intended use in air brake
systems.
S11.2.2 End fittings. Except for an end fitting that is attached by
deformation of the fitting about the tubing by crimping or swaging, at
least one component of each plastic air brake tubing end fitting shall
be etched, embossed, or stamped in block capital letters and numerals at
least one-sixteenth of an inch high with the following information:
(a) The symbol DOT, constituting a certification by the manufacturer
that the end fitting conforms to all applicable motor vehicle safety
standards.
(b) A designation that identifies the manufacturer of the end
fitting, which shall be filed in writing with: Office of Vehicle Safety
Compliance, Equipment Division NVS-222, National Highway Traffic Safety
Administration, 400 Seventh St. SW., Washington, DC 20590. The
designation may consist of block capital letters, numerals, or a symbol.
(c) The letter ``A'' shall indicate intended use in air brake
systems.
(d) The nominal outside diameter of the plastic tubing to which the
fitting is properly attached expressed in inches or fractions of inches
or in millimeters followed by the letters OD. The abbreviation ``mm''
shall follow tubing sizes that are expressed in millimeters. (Examples:
\3/8\ OD, 6 mm OD)
S11.2.3. Assemblies. Each plastic air brake tubing assembly made
with end fittings that are attached by crimping or swaging, except those
sold as part of a motor vehicle, shall be labeled by means of a band
around the brake tubing assembly as specified in this paragraph or, at
the option of the manufacturer, by means of labeling as specified in
S11.2.3.1. The band may at the manufacturer's option be attached so as
to move freely along the length of the assembly, as long as it is
retained by the end fittings. The band shall be etched, embossed, or
stamped in block capital letters, numerals or symbols at least one-
eighth of an inch high, with the following information:
(a) The symbol DOT, constituting certification by the tubing
assembler that the tubing assembly conforms to all applicable motor
vehicle safety standards.
(b) A designation that identifies the manufacturer of the hose
assembly, which shall be filed in writing with: Office of Vehicle Safety
Compliance, Equipment Division NVS-222, National Highway Traffic Safety
Administration, 400 Seventh St. SW., Washington, DC 20590. The
designation may consist of block capital letters, numerals, or a symbol.
S11.2.3.1 At least one end fitting of a plastic air brake tubing
assembly made with end fittings that are attached by crimping or swaging
shall be etched, stamped, or embossed with a designation at least one-
sixteenth of an inch high that identifies the manufacturer of the tubing
assembly and is filed in accordance with S11.2.3(b).
S11.3 Test requirements. Each plastic air brake tubing assembly or
appropriate part thereof shall be capable of meeting any of the
requirements set forth under this heading, when tested under the
conditions of S13 and the applicable procedures of S12. However, a
particular tubing assembly or appropriate part thereof need not meet
further requirements after having met the constriction requirement
(S11.3.1) and then having been subjected to any one of the requirements
specified in S11.3.2 through S11.3.22. Unless otherwise specified,
testing is conducted on a sample of tubing 12 inches in length.
S11.3.1 Constriction. Every inside diameter of any section of a
plastic air brake tubing assembly shall not be less than 66 percent of
the nominal inside diameter of the brake tubing. (S12.2)
S11.3.2 High temperature conditioning and dimensional stability.
Plastic air brake tubing shall conform to the dimensions in Table VII
after conditioning in air at 230 degrees Fahrenheit (110 degrees
Celsius) for four hours. (S12.3)
S11.3.3 Boiling water conditioning and dimensional stability.
Plastic air brake tubing shall conform to the dimensions in Table VII
after conditioning in boiling water for two hours. (S12.4)
[[Page 281]]
S11.3.4 Burst Strength. Plastic air brake tubing shall not rupture
when subjected to the burst strength pressure in Table VIII for the size
of tubing being tested. (S12.5)
S11.3.5 Moisture absorption and burst strength. Plastic air brake
tubing shall not rupture when subjected to 80 percent of the burst
strength pressure in Table VIII, after the tubing has been dried in an
oven and then conditioned in a 100 percent relative humidity atmosphere
at 75 degrees Fahrenheit (24 degrees Celsius) for 100 hours. (S12.6)
Table VIII.--Plastic Air Brake Tubing Mechanical Properties
----------------------------------------------------------------------------------------------------------------
Burst strength Supported bend Unsupported bend Conditioned
pressure radius \1\ radius \2\ tensile load
Nominal tubing OD -----------------------------------------------------------------------
kPa Psi Mm inches mm inches N lbf
----------------------------------------------------------------------------------------------------------------
\1/8\ inch.............................. 6900 1000 9.4 0.37 9.4 0.37 156 35
\5/32\ inch............................. 8300 1200 12.7 0.50 12.7 0.50 178 40
\3/16\ inch............................. 8300 1200 19.1 0.75 19.1 0.75 222 50
\1/4\ inch.............................. 8300 1200 25.4 1.00 25.4 1.00 222 50
\5/16\ inch............................. 6900 1000 31.8 1.25 38.1 1.50 334 75
\3/8\ inch.............................. 9700 1400 38.1 1.50 38.1 1.50 667 150
\1/2\ inch.............................. 6600 950 50.8 2.00 63.5 2.50 890 200
\5/8\ inch.............................. 6200 900 63.5 2.50 76.2 3.00 1446 325
\3/4\ inch.............................. 5500 800 76.2 3.00 88.9 3.50 1557 350
6 mm.................................... 7600 1100 20.0 0.75 25.4 1.00 222 50
8 mm.................................... 6200 900 31.8 1.25 38.1 1.50 334 75
10 mm................................... 8200 1200 38.1 1.50 38.1 1.50 667 150
12 mm................................... 6900 1000 44.5 1.75 63.5 2.50 890 200
16 mm................................... 6000 875 69.9 2.75 76.2 3.00 1446 325
----------------------------------------------------------------------------------------------------------------
Notes: (1) Supported bend radius for tests specifying cylinders around which the tubing is bent. (2) Unsupported
bend radius for the collapse resistance test in which the tubing is not supported by a cylinder during
bending.
S11.3.6 Ultraviolet light resistance. Plastic air brake tubing shall
not rupture when subjected to 80 percent of the burst strength pressure
in Table VIII for the size of tubing being tested, after being exposed
to ultraviolet light for 300 hours and then impacted with a one pound
weight dropped from a height of 12 inches. (S12.7)
S11.3.7 Low temperature flexibility. The outer surface of plastic
air brake tubing shall not show cracks visible without magnification as
a result of conditioning in air at 230 degrees Fahrenheit (110 degrees
Celsius) for 24 hours, and then conditioning in air at minus 40 degrees
Fahrenheit (minus 40 degrees Celsius) for four hours, and then bending
the tubing 180 degrees around a test cylinder having a radius equal to
six times the nominal outside diameter of the tubing. (S12.8)
S11.3.8 High temperature flexibility. Plastic air brake tubing shall
not rupture or burst when subjected to 80 percent of the burst strength
pressure in Table VIII for the size of tubing being tested, after the
tubing has been:
(a) Conditioned in air at 230 degrees Fahrenheit (110 degrees
Celsius) for 72 hours while bent 180 degrees around a cylinder having a
radius equal to the supported bend radius in Table VIII for the size of
tubing being tested; and
(b) Cooled to room temperature while remaining on the cylinder, then
straightened; and
(c) Bent 180 degrees around the cylinder in the opposite direction
of the first bending. (S12.9)
S11.3.9 High temperature resistance. Plastic air brake tubing shall
not rupture or burst when subjected to 80 percent of the burst strength
pressure in Table VIII for the size of tubing being tested, after the
tubing has been conditioned in air at 230 degrees Fahrenheit (110
degrees Celsius) for 72 hours. (S12.10)
S11.3.10 High temperature conditioning, low temperature impact
resistance. Plastic air brake tubing shall not rupture or burst when
subjected to 80 percent of the burst strength pressure in Table VIII for
the size of tubing being tested, after the tubing has been conditioned
in air at 230 degrees Fahrenheit (110 degrees Celsius) for 24 hours,
then conditioned in air at minus 40 degrees Fahrenheit (minus 40 degrees
Celsius) for 4 hours and impacted with a one pound weight dropped from a
height of 12 inches. (S12.11)
S11.3.11 Boiling water conditioning, low temperature impact
resistance. Plastic air brake tubing shall not rupture when subjected to
80 percent of the burst strength pressure in Table VIII for the size of
tubing being tested, after the tubing has been conditioned in boiling
water for two hours, then conditioned in air at minus 40 degrees
Fahrenheit (minus 40 degrees Celsius) for 4 hours, and then impacted
with a one pound weight dropped from a height of 12 inches. (S12.12)
S11.3.12 Zinc chloride resistance. The outer surface of plastic air
brake tubing shall not
[[Page 282]]
show cracks visible under 7-power magnification after immersion in a 50
percent zinc chloride aqueous solution for 200 hours while bent around a
cylinder having a radius equal to the supported bend radius in Table
VIII for the size of tubing tested. (S12.13)
S11.3.13 Methyl alcohol resistance. The outer surface of plastic air
brake tubing shall not show cracks visible under 7-power magnification
after immersion in a 95 percent methyl alcohol aqueous solution for 200
hours while bent around a cylinder having a radius equal to the
supported bend radius in Table VIII for the size of tubing tested.
(S12.14)
S11.3.14 High temperature conditioning and collapse resistance. The
collapse of the outside diameter of plastic air brake tubing shall not
exceed twenty percent of the original outside diameter when bent 180
degrees on a holding fixture to the unsupported bend radius specified in
Table VIII and conditioned in air at 200 degrees Fahrenheit (93 degrees
Celsius) for 24 hours. (S12.15)
S11.3.15 Ozone resistance. The outer surface of plastic air brake
tubing shall not show cracks visible under 7-power magnification after
exposure to ozone for 70 hours at 104 degrees Fahrenheit (40 degrees
Celsius). (S12.16)
S11.3.16 Oil resistance. Plastic air brake tubing shall not rupture
when subjected to 80 percent of the burst strength pressure in Table
VIII for the size of tubing being tested, after the tubing has been
conditioned in ASTM IRM 903 oil at 212 degrees Fahrenheit (100 degrees
Celsius) for 70 hours. (S12.17)
S11.3.17 Tensile strength. A plastic air brake tubing assembly
designed for use between frame and axle or between a towed and a towing
vehicle shall withstand, without separation of the tubing from its end
fittings, a pull of 250 pounds if it is \3/8\ inch, 10 mm, or less in
nominal outside diameter, or a pull of 325 pounds if it is larger than
\3/8\ inch or 10 mm in nominal outside diameter. A plastic air brake
tubing assembly designed for use in any other application shall
withstand, without separation of the hose from its end fittings, a pull
of 35 pounds if it is \1/8\ inch, 3 mm, or less in nominal outside
diameter, 40 pounds if it is \5/32\ inch or 4 mm in nominal outside
diameter, 50 pounds if it is \3/16\ to \3/8\ inch or 5 mm to 10 mm in
nominal outside diameter, 150 pounds if it is \1/2\ to \5/8\ inch or 11
mm to 16 mm in nominal outside diameter, or 325 pounds if it is larger
than \5/8\ inch or 16 mm in nominal outside diameter. (S12.18)
S11.3.18 Boiling water conditioning and tensile strength. A plastic
air brake tubing assembly when subjected to a tensile pull test shall
either elongate 50 percent or withstand the conditioned tensile load in
Table VIII without separation from its end fittings, with one end of the
assembly conditioned in boiling water for 5 minutes. (S12.19)
S11.3.19 Thermal conditioning and tensile strength. A plastic air
brake tubing assembly when subjected to a tensile pull test shall either
elongate 50 percent or withstand the conditioned tensile load in Table
VIII without separation from its end fittings after the assembly has
been subjected to four cycles of conditioning in air at minus 40 degrees
Fahrenheit (minus 40 degrees Celsius) for thirty minutes, normalizing at
room temperature, conditioning in boiling water for 15 minutes, and
normalizing at room temperature. (S12.20)
S11.3.20 Vibration resistance. A plastic air brake tubing assembly
with an internal air pressure of 120 psig shall not rupture or leak more
than 50 cm\3\ per minute at a temperature of minus 40 degrees Fahrenheit
(minus 40 degrees Celsius) and 25 cm\3\ per minute at a temperature of
75 degrees Fahrenheit (24 degrees Celsius), after the assembly has been
subjected to 1,000,000 cycles of vibration testing with one end of the
assembly fixed and the other end stroked \1/2\-inch at 600 cycles per
minute. In addition, end fittings that use a threaded retention nut
shall retain at least 20 percent of the original retention nut
tightening torque upon completion of the vibration testing. The
vibration test shall be conducted in an environmental chamber and the
air temperature shall be cycled between minus 40 degrees Fahrenheit
(minus 40 degrees Celsius) and 220 degrees Fahrenheit (104 degrees
Celsius) during the test. (S12.21)
S11.3.21 End fitting retention. The end fittings of a plastic air
brake tubing assembly shall not rupture when the assembly is filled with
water and pressurized to the burst strength pressure in Table VIII.
(S12.22)
S11.3.22 Thermal conditioning and end fitting retention. The end
fittings of a plastic air brake tubing assembly shall not rupture when
the tubing assembly is filled with ASTM IRM 903 oil and:
(a) Conditioning in air at 200 degrees Fahrenheit (93 degrees
Celsius) for 24 hours with atmospheric pressure inside the tubing
assembly; and
(b) Increasing the pressure inside the tubing assembly to 450 psi,
and holding this pressure for five minutes while maintaining an air
temperature of 200 degrees Fahrenheit (93 degrees Celsius); and
(c) Reducing the pressure inside the tubing assembly to atmospheric
and permitting the tubing assembly to cool at 75 degrees Fahrenheit (24
degrees Celsius) for 1 hour; and
(d) Conditioning the tubing assembly in air at minus 40 degrees
Fahrenheit (minus 40 degrees Celsius) for 24 hours with atmospheric
pressure inside the tubing assembly; and
(e) Increasing the pressure inside the tubing assembly to 450 psi,
and holding this pressure for five minutes while maintaining an air
temperature of minus 40 degrees Fahrenheit (minus 40 degrees Celsius).
(S12.23)
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S11.3.23 End fitting serviceability. A plastic air brake end fitting
that uses a threaded retention nut shall not rupture or leak more than
25 cm\3\ per minute when pressurized to 120 psi after five assembly
cycles. (S12.24)
S11.3.24 End fitting corrosion resistance. After 24 hours of
exposure to salt spray, air brake hose end fittings shall show no base
metal corrosion on the end fitting surface except where crimping or the
application of labeling information causes a displacement of the
protective coating. (S12.25)
S12. Test procedures--Plastic air brake tubing, plastic air brake
tubing assemblies, plastic air brake tubing end fittings.
S12.1 Air brake tubing dimensions. Measure the tubing dimensions
including wall thickness, inside diameter, and outside diameter, using
appropriate metrology apparatus such as micrometers, dial indicators and
gauges, or optical comparators. To account for slight out-of-round
conditions, diameter measurements may be calculated using the average of
the major and minor diameters.
S12.2 Constriction test. Perform the constriction test in S6.12
using an air brake tubing assembly, except that the spherical diameter
``A'' of the plug gauge in Figure 4, or the diameter of the rigid
spherical ball in S6.12.3(a), shall be 66 percent of the nominal inside
diameter of the tubing as specified in Table VII.
S12.3 High temperature conditioning and dimensional stability test.
(a) Condition the tubing at 230 degrees Fahrenheit (110 degrees Celsius)
for 4 hours in an air oven.
(b) Remove the tubing from the oven and allow to cool at room
temperature for 30 minutes.
(c) Measure the dimensions of the tubing using the procedure in
S12.1.
S12.4 Boiling water conditioning and dimensional stability test. (a)
Utilize a container constructed of a non-reactive material large enough
so that the tubing to be tested does not touch any surface of the
container. Fill container with distilled water.
(b) Slip the tubing over a stainless steel wire for positioning it
in the pot.
(c) Bring the water to a boil. Place the tubing in the water and
position it so that it does not touch the container. Boil the tubing for
two hours. Replenish the water as necessary, adding it slowly so that
the water in the pot boils continuously.
(d) Remove the tubing from the water and allow to cool at room
temperature for 30 minutes. Wipe off any water that remains on the
tubing.
(e) Measure the dimensions of the tubing using the procedure in
S12.1.
S12.5 Burst strength test. (a) Utilize an air brake tubing assembly
or prepare a 12 inch length of tubing and install end fittings according
to the end fitting manufacturer's instructions.
(b) Plug one end of the assembly, fill it with water, and connect
the other end to a source of water pressure. Bleed any air from the
assembly and water pressure system.
(c) Increase the water pressure inside the tubing assembly at a rate
of 3,000 psi per minute to the burst strength pressure for the size of
tubing being tested as specified in Table VIII.
S12.6 Moisture absorption and burst strength. (a) Prepare a sample
of tubing twelve inches in length.
(b) Condition the tubing at 230 degrees Fahrenheit (110 degrees
Celsius) for 24 hours in an air oven. Remove the tubing from the oven
and within 30 seconds, and weigh it to establish the initial weight. The
weight shall be measured with a resolution of 0.01 gram; if the scale
has a higher resolution, then values of 0.005 gram and above shall be
rounded to the nearest 0.01 gram and values below 0.005 gram shall be
truncated.
(c) Place the tubing in an environmental chamber and condition it
for 100 hours at 100 percent relative humidity and a temperature of 75
degrees Fahrenheit (24 degrees Celsius).
(d) Remove the tubing from the chamber and within a period of 5
minutes, remove all surface moisture from the tubing using cloth and
weigh the tubing to establish the conditioned weight. Weight shall be
measured to the nearest 0.01 gram as in S12.6(b).
(e) Calculate percentage of moisture absorption as follows:
([Conditioned Weight-Initial Weight]) [Initial Weight] x 100
(f) Install end fittings according to the end fitting manufacturers
instructions.
(g) Conduct the burst strength test in 12.5 except use 80 percent of
the burst strength pressure for the size of tubing being tested as
specified in Table VIII.
S12.7 Ultraviolet light resistance test. (a) Apparatus. An
accelerated weathering test machine for ultraviolet light conditioning
of plastic air brake tubing. The machine shall be equipped with
fluorescent UVA-340 light bulbs and automatic irradiance control. Also
utilize an impact test apparatus as shown in Figure 8.
(b) Test standards. The testing is in accordance with American
Society for Testing and Materials (ASTM) G154-00 ``Standard Practice for
Operating Fluorescent Light Apparatus for UV Exposure of Nonmetallic
Materials;'' ASTM G151-97 ``Standard Practice for Exposing Nonmetallic
Materials in Accelerated Test Devices that Use Laboratory Light
Sources,'' and; ASTM D4329-99 ``Standard Practice for Fluorescent UV
Exposure of Plastics.'' These incorporations by reference were approved
by the Director of the Federal Register in accordance with 5 U.S.C.
552(a) and 1 CFR Part 51. Copies may be obtained from the American
Society for Testing and Materials (ASTM) International, 100 Barr
[[Page 284]]
Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959. Copies
may be inspected at the National Highway Traffic Safety Administration,
Technical Information Services, 400 Seventh St., SW., Plaza Level, Room
403, Washington, DC 20590, or at the National Archives and Records
Administration (NARA). For information on the availability of this
material at NARA, call (202) 741-6030, or go to: http://
www.archives.gov/federal--register/code--of--federal--regulations/ibr--
locations.html.
(c) Preparation. (1) Utilize a 12 inch length of plastic air brake
tubing. Mask 1 inch of each end of the tubing where end fittings will be
attached using opaque tape.
(2) Attach the tubing to the test rack of the machine, securing it
at the ends along the masked sections. Wipe the outside surface of the
tubing with acetone to remove any surface contaminants. Place the tubing
and rack in the accelerated weathering test machine so that the center
of the tubing assembly is approximately in the center of the UV light
exposure area of the test machine. (If multiple plastic brake tubing
assemblies are tested, then their position in the machine should be
rotated according to ASTM D4329-99 S7.4.1, except the rotation shall be
each 96 hours instead of weekly.) The distance from the light bulb to
the tubing shall be approximately 2 inches. Set the UV irradiance to
0.85 watts per square meter at 340 nm and maintain this level during the
testing. Maintain a temperature inside the test chamber of 113 degrees
Fahrenheit (45 degrees Celsius), and use only atmospheric humidity.
Expose the tubing at this UV irradiance level for 300 hours
continuously. Remove the tubing from the test chamber.
(3) Place the tubing inside the impact test apparatus, and drop the
impacter onto the tubing from a height of 12 inches.
(4) Remove the masking material from the ends of the tubing. Install
end fittings according to the end fitting manufacturer's instructions.
Conduct the burst strength test in S12.5 except use 80 percent of the
burst strength pressure for the size of tubing being tested as specified
in Table VIII.
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[GRAPHIC] [TIFF OMITTED] TR20DE04.007
Table Accompanying Figure 8
------------------------------------------------------------------------
Hole diameter
``D''
Nominal tubing outside diameter -----------------
mm Inches
------------------------------------------------------------------------
\1/8\ inch............................................ 3.96 0.156
\5/32\ inch........................................... 4.75 0.187
\3/16\ inch........................................... 5.54 0.218
\1/4\ inch............................................ 7.14 0.281
[[Page 286]]
\5/16\ inch........................................... 8.71 0.343
\3/8\ inch............................................ 10.31 0.406
\1/2\ inch............................................ 13.49 0.531
\5/8\ inch............................................ 16.66 0.656
\3/4\ inch............................................ 20.32 0.800
6 mm.................................................. 6.80 0.268
8 mm.................................................. 8.80 0.346
10 mm................................................. 10.80 0.425
12 mm................................................. 12.80 0.504
16 mm................................................. 16.80 0.661
------------------------------------------------------------------------
S12.8 Low temperature flexibility test. (a) Utilize a cylinder
having a radius of six times the nominal outside diameter of the tubing.
(b) Condition the tubing in an air oven at 230 degrees Fahrenheit
(110 degrees Celsius) for 24 hours. Remove from the oven and cool at
room temperature for 30 minutes.
(c) Condition the cylinder and the tubing in an environmental
chamber at minus 40 degrees Fahrenheit (minus 40 degrees Celsius) for
four hours.
(d) With the tubing and test cylinder at minus 40 degrees Fahrenheit
(minus 40 degrees Celsius), bend the tubing 180 degrees around the
cylinder at a steady rate in a period of 4 to 8 seconds.
S12.9 High temperature flexibility test. (a) Utilize a cylinder
having a radius equal to the supported bend radius in Table VIII for the
size of tubing being tested.
(b) Bend the tubing 180 degrees around the cylinder and hold in
place with a clamp or other suitable support, applying only enough force
on the tubing to hold it in position.
(c) Condition the tubing and cylinder in an air oven at 230 degrees
Fahrenheit (110 degrees Celsius) for 72 hours. Remove the tubing and
cylinder from the oven and cool at room temperature for two hours.
(d) Remove the clamps or supports from the tubing and straighten the
tubing at a steady rate in a period of 4 to 8 seconds.
(e) Rebend the tubing 180 degrees around the cylinder, at the same
point but in the opposite direction of the bending in S12.9(b), at a
steady rate in a period of 4 to 8 seconds.
(f) Conduct the burst strength test in S12.5 except use 80 percent
of the burst strength pressure for the size of tubing being tested as
specified in Table VIII.
S12.10 High temperature resistance test. Condition the tubing in an
air oven at 230 degrees Fahrenheit for 72 hours. Remove the tubing and
allow to cool at room temperature for 30 minutes. Conduct the burst
strength test in S12.5 except use 80 percent of the burst strength
pressure for the size of tubing being tested as specified in Table VIII.
S12.11 High temperature conditioning, low temperature impact
resistance test. (a) Apparatus. Utilize an impact test apparatus as
shown in Figure 8.
(b) Condition the tubing in an air oven at 230 degrees Fahrenheit
(110 degrees Celsius) for 72 hours. Remove the tubing and allow to cool
at room temperature for 30 minutes.
(c) Condition the tubing and the impact test apparatus in an
environmental chamber at minus 40 degrees Fahrenheit (minus 40 degrees
Celsius) for 4 hours.
(d) With the tubing and impact test apparatus at minus 40 degrees
Fahrenheit (minus 40 degrees Celsius), place the tubing inside the
apparatus and drop the impacter onto the tubing from a height of 12
inches. Remove the tubing from the chamber and allow to warm at room
temperature for one hour.
(e) Conduct the burst strength test in S12.5 except use 80 percent
of the burst strength pressure for the size of tubing being tested as
specified in Table VIII.
S12.12 Boiling water conditioning, low temperature impact resistance
test. (a) Apparatus. Utilize an impact test apparatus as shown in Figure
8.
(b) Condition the tubing in boiling water using the test in S12.4
(a) through (d), except that the length of tubing shall be 12 inches.
(c) Condition the tubing and the impact test apparatus in an
environmental chamber at minus 40 degrees Fahrenheit (minus 40 degrees
Celsius) for 4 hours.
(d) With the tubing and impact test apparatus at minus 40 degrees
Fahrenheit (minus 40 degrees Celsius), place the tubing inside the
apparatus and drop the impacter onto the tubing from a height of 12
inches. Remove the tubing from the chamber and allow to warm at room
temperature for one hour.
(e) Conduct the burst strength test in S12.5 except use 80 percent
of the burst strength pressure for the size of tubing being tested as
specified in Table VIII.
S12.13 Zinc chloride resistance test. (a) Utilize a cylinder having
a radius equal to the supported bend radius in Table VIII for the size
of tubing being tested. The cylinder is constructed of a non-reactive
material or coated to prevent chemical reaction with zinc chloride. The
length of the tubing sample is long enough so that its ends will not be
submerged during the immersion in zinc chloride, or the ends of the
tubing are plugged to keep the zinc chloride from entering the tubing.
(b) Bend the tubing 180 degrees around the cylinder and hold in
place with a clamp or other suitable support constructed of non-reactive
materials, applying only enough force on the tubing to hold it in
position.
(c) Immerse the tubing and cylinder in a 50 percent zinc chloride
aqueous solution at room temperature for 200 hours.
(d) Remove the tubing and cylinder from the solution. While still on
the test cylinder,
[[Page 287]]
inspect the tubing under 7-power magnification for cracks.
S12.14 Methyl alcohol resistance. (a) Utilize a cylinder having a
radius equal to the supported bend radius in Table VIII for the size of
tubing being tested. The cylinder is constructed of a non-reactive
material or coated to prevent chemical reaction with methyl alcohol.
(b) Bend the tubing 180 degrees around the cylinder and hold in
place with a clamp or other suitable support constructed of non-reactive
materials, applying only enough force on the tubing to hold it in
position. The ends of the tubing may be shortened so that they will be
fully submerged in the methyl alcohol.
(c) Immerse the tubing and cylinder in a 95 percent methyl alcohol
aqueous solution at room temperature for 200 hours.
(d) Remove the tubing and cylinder from the solution. While still on
the test cylinder, inspect the tubing under 7-power magnification for
cracks.
S12.15 High temperature conditioning and collapse resistance test.
(a) Apparatus. A holding device consisting of two vertical pins affixed
to a flat, horizontal plate. Each pin projects 1 inch above the top
surface of the plate. The diameter of each pin is approximately equal to
the inside diameter of the tubing being tested. Using the unsupported
bend radius for the size of tubing being tested from Table VIII, the
distance between the pin centerlines is equal to:
[2 x unsupported bend radius] + [nominal OD of tubing]
(b) Preparation. (1) Use the unsupported bend radius for the size of
tubing being tested from Table VIII and cut the tubing to the following
length:
[3.14 x [unsupported bend radius]] + [10 x [nominal tubing OD]] + 2
inches
or
[3.14 x [unsupported bend radius]] + [10 x [nominal tubing OD]] + 50 mm
(2) Place a reference mark at the center of the sample. At this
mark, measure the initial outside diameter of the tubing. If the tubing
is slightly out-of-round, use the elliptical minor diameter as the
initial outside diameter.
(3) Install the tubing completely over the pins of the holding
device so that the tubing is bent 180 degrees. If the tubing has a
natural curvature, the tubing shall be bent in the direction of the
natural curvature.
(4) Condition the holding device and tubing in an air oven at 230
degrees Fahrenheit (110 degrees Celsius) for 24 hours. Remove the
holding device and tubing and allow to cool at room temperature for
thirty minutes.
(5) With the tubing still mounted to the holding device, measure the
elliptical minor diameter of the tubing at the reference mark to
determine the final outside diameter.
(c) Calculation. Calculate the percentage collapse of the outside
diameter of the tubing as follows:
([Initial Outside Diameter - Final Outside Diameter]) [Initial Outside
Diameter] x 100
S12.16 Ozone resistance test. Conduct the test specified in S6.8
using plastic air brake tubing.
S12.17 Oil resistance test. (a) Utilize a plastic air brake tubing
assembly or prepare a 12 inch length of tubing and install end fittings
according to the end fitting manufacturer's instructions.
(b) Immerse the tubing assembly in ASTM 903 oil at 212 degrees
Fahrenheit (100 degrees Celsius) for 70 hours. Remove and allow to cool
at room temperature for 30 minutes. Wipe any excess oil from the tubing
assembly.
(c) Conduct the burst strength test in S12.5 except use 80 percent
of the burst strength pressure for the size of tubing being tested as
specified in Table VIII and, at the manufacturer's option, oil may be
used as the test medium instead of water.
S12.18 Tensile strength test. Conduct the test in S8.9 using a
plastic air brake tubing assembly or an assembly prepared from a 12 inch
length of air brake tubing with end fittings installed according to the
end fitting manufacturer's instructions.
S12.19 Boiling water conditioning and tensile strength. (a)
Apparatus. Use a tension testing machine as specified in S8.9. The lower
attachment point of the machine is equipped with a heated, open-top
container that is water tight. The inside of the container (lower
attachment point) and upper attachment point of the machine have
provisions to quickly attach a brake hose assembly for tensile testing.
(b) Preparation. Prepare an air brake tubing assembly with a free
length of 6 inches (six inches of exposed tubing between the end
fittings), with the end fittings installed in accordance with the end
fitting manufacturer's instructions. If necessary install adapters on
the end fittings to permit quick attachment to the machine, to keep
water from entering the tubing assembly, and to ensure that the tubing
assembly is in a straight position when installed on the machine. Fill
the container with distilled water such that the lower 4 inches of
exposed tubing will be submerged when the brake tubing assembly is
installed on the machine. Heat the water until it boils. Then quickly
install the plastic air brake tubing assembly on the machine with the
lower end of the tubing assembly in the boiling water. After the water
has boiled continuously for 5 minutes, apply tension to the tubing
assembly at a rate of 1 inch per minute travel of the moving head until
either the conditioned tensile load in
[[Page 288]]
Table VIII for the size of tubing being tested is reached or the free
length of the tubing assembly reaches 9 inches, whichever occurs first.
S12.20 Thermal conditioning and tensile strength. (a) Apparatus. Use
a tension testing machine as specified in S8.9.
(b) Preparation. Prepare an air brake tubing assembly with a free
length of 6 inches (six inches of exposed tubing between the end
fittings), with the end fittings installed in accordance with the end
fitting manufacturer's instructions. If necessary install adapters on
the end fittings to permit attachment to the machine, to keep water from
entering the tubing assembly, and/or to ensure that the tubing assembly
is in a straight position when installed on the machine. Subject the
tubing assembly to four complete cycles of the following sequence:
(1) Condition the tubing assembly in an environmental chamber at
minus 40 degrees Fahrenheit (minus 40 degrees Celsius) for 30 minutes.
Remove from the chamber and allow to warm at room temperature for 30
minutes.
(2) Condition the tubing assembly by submerging it in boiling water
for 15 minutes. Remove and allow to cool at room temperature for 30
minutes. Install the tubing assembly on the tension testing machine and
apply tension to the tubing assembly at a rate of one inch per minute
travel of the moving head until either the conditioned tensile load in
Table VIII for the size of tubing being tested is reached or the free
length of the tubing assembly reaches 9 inches, whichever occurs first.
S12.21 Vibration resistance test. (a) Apparatus. A vibration testing
machine that supports a brake tubing assembly by its end fittings in
approximately a straight line and includes the following features:
(1) One tubing assembly attachment point is fixed and the other
moves in a plane perpendicular to a line projected between the
attachment points. The movable attachment point moves in a linear
direction and travels \1/2\ inch total and at its midpoint of travel
falls on a line projected between the attachment points. The movable
attachment point has a cycle rate of 600 cycles per minute.
(2) The distance between the attachment points is adjustable to
compensate for varying lengths of brake tubing assemblies.
(3) The actuating mechanism for the movable attachment point is
balanced to prevent introduction of machine vibration into the brake
tubing assembly.
(4) The machine has a compressed air supply system that pressurizes
the air brake tubing assembly through one fitting while the other
fitting is plugged. The machine's compressed air supply system includes
a pressure gauge or monitoring system and an air flow meter.
(5) The machine is constructed so that an air brake tubing assembly
mounted on it can be conditioned in an environmental test chamber.
(b) Preparation. (1) Prepare an air brake tubing assembly with a
free length of 18 inches (18 inches of exposed tubing between the end
fittings), with the end fittings installed in accordance with the end
fitting manufacturer's instructions. Record the initial tightening
torque for an end fitting that uses a threaded retaining nut.
(2) Install the air brake tubing assembly on the vibration testing
machine and, with the movable attachment point at the midpoint of its
travel, adjust the distance between the attachment points so that they
are \1/2\ inch closer together than the distance at which the tubing
assembly is taut.
(3) With the tubing assembly inside the environmental chamber, apply
compressed air to the tubing assembly at a regulated pressure of 120 psi
and maintain the supply of air to the tubing assembly for the duration
of the test. Set the temperature of the environmental chamber to 220
degrees Fahrenheit (104 degrees Celsius) and initiate cycling of the
movable attachment point. After 250,000 cycles, set the temperature of
the environmental chamber to minus 40 degrees Fahrenheit (minus 40
degrees Celsius). After 500,000 cycles, set the temperature of the
environmental chamber to 220 degrees Fahrenheit (104 degrees Celsius).
After 750,000 cycles, set the temperature of the environmental chamber
to minus 40 degrees Fahrenheit (minus 40 degrees Celsius). Measure the
air flow rate just prior to 1,000,000 cycles and if the compressed air
flow rate supplied to the air brake tubing assembly exceeds 50 cubic
centimeters per minute this constitutes failure of the test. Stop the
cycling at 1,000,000 cycles and set the environmental chamber
temperature to 75 degrees Fahrenheit (24 degrees Celsius), while air
pressure is still supplied to the air brake tubing assembly. After one
hour, measure the compressed air flow rate supplied to the air brake
tubing assembly and if the rate exceeds 25 cubic centimeters per minute
this constitutes failure of the test.
(4) For end fittings that use a threaded retaining nut, apply 20
percent of the original tightening torque as recorded in S12.21(b)(1).
If the retention nut visibly moves, this constitutes a failure of the
test.
S12.22 End fitting retention test. (a) Utilize an air brake tubing
assembly or prepare a 12 inch length of tubing and install end fittings
according to the end fitting manufacturer's instructions.
(b) Plug one end of the assembly, fill it with water, and connect
the other end to a source of water pressure. Bleed any air from the
assembly and water pressure system.
(c) Increase the pressure inside the tubing assembly at a rate of
3,000 psi per minute to
[[Page 289]]
50 percent of the burst strength pressure for the size of tubing being
tested as specified in Table VIII. Hold the pressure constant for 30
seconds.
(d) Increase the pressure inside the tubing assembly at a rate of
3,000 psi per minute to the burst strength pressure for the size of
tubing being tested as specified in Table VIII.
S12.23 Thermal conditioning and end fitting retention test. (a)
Apparatus. A source of hydraulic pressure that includes a pressure gauge
or monitoring system, uses ASTM IBM 903 oil, and is constructed so that
an air brake tubing assembly mounted to it can be conditioned in an
environmental test chamber.
(b) Preparation. Utilize an air brake tubing assembly or prepare a
12 inch length of tubing and install end fittings according to the end
fitting manufacturer's instructions. Attach one end of the assembly to
the hydraulic pressure supply and plug the other end of the assembly,
fill the assembly with ASTM IRM 903 oil and bleed any air from the
assembly, and place the tubing assembly inside an environmental chamber.
Conduct the following tests:
(1) With atmospheric pressure applied to the oil inside the tubing
assembly, set the environmental chamber temperature to 200 degrees
Fahrenheit (93 degrees Celsius) and condition the tubing assembly for 24
hours.
(2) With the temperature maintained at 200 degrees Fahrenheit (93
degrees Celsius), increase the oil pressure inside the tubing assembly
at a rate of 3,000 psi per minute to 450 psi, and hold this pressure for
5 minutes.
(3) Decrease the oil pressure inside the tubing assembly at a rate
of 3,000 psi per minute to atmospheric pressure and set the temperature
of the environmental chamber to 75 degrees Fahrenheit (24 degrees
Celsius). Condition the tubing assembly at this temperature for 1 hour.
(4) Set the temperature of the environmental chamber to minus 40
degrees Fahrenheit (minus 40 degrees Celsius) and condition the tubing
assembly for 24 hours.
(5) With the temperature maintained at minus 40 degrees Fahrenheit
(minus 40 degrees Celsius), increase the hydraulic pressure inside the
tubing assembly at a rate of 3,000 psi per minute to 450 psi, and hold
this pressure for 5 minutes.
S12.24 End fitting serviceability. (a) Apparatus. A source of air
pressure that includes a pressure gauge or monitoring system and is
equipped with a mass air flow meter.
(b) Preparation. Prepare a 12-inch length of tubing and plug one
end. Assemble the end fitting with the threaded retention nut on the
other end of the tubing according to the end fitting manufacturer's
instructions, then disassemble the fitting. Repeat the assembly and
disassembly sequence three more times, and then reassemble the end
fitting (five total assembly steps).
(c) Attach the end fitting with the threaded retention nut to the
source of air pressure. Pressurize the tubing at a rate of 3,000 psi per
minute to a pressure of 120 psi. If the end fitting leaks, measure and
record the leakage rate using the mass air flow meter.
S12.25 End fitting corrosion resistance. Utilize an air brake tubing
assembly or prepare a 12-inch length of tubing and install end fittings
according to the end fitting manufacturer's instructions. Conduct the
test specified in S6.11 using a plastic air brake tubing assembly.
S13. Test Conditions. Each hose assembly or appropriate part thereof
shall be able to meet the requirements of S5, S7, S9, and S11, under the
following conditions.
S13.1 The temperature of the testing room is 75 degrees Fahrenheit
(24 degrees Celsius).
S13.2 The brake hoses and brake hose assemblies are at least 24
hours old, and unused.
S13.3 Specified test pressures are gauge pressures (psig).