[Code of Federal Regulations]
[Title 46, Volume 2]
[Revised as of October 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 46CFR56.50-1]

[Page 193-194]
 
                           TITLE 46--SHIPPING
 
   CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED)
 
PART 56_PIPING SYSTEMS AND APPURTENANCES--Table of Contents
 
    Subpart 56.50_Design Requirements Pertaining to Specific Systems
 
Sec. 56.50-1  General (replaces 122.6 through 122.10).


    The piping requirements in this subpart shall apply in lieu of 
requirements in 122.6 through 122.10 of ANSI-B31.1. Installation 
requirements applicable to all systems:
    (a) Where pipes and scuppers are carried through watertight or 
oiltight bulkheads, decks or tank tops, or are carried through fire 
control bulkheads and decks, the integrity of the structure shall be 
maintained. Lead or other heat sensitive materials shall not be used in 
piping systems which make such bulkhead or deck penetrations where the 
deterioration of such systems in the event of fire would impair the 
integrity of the bulkheads or decks. (For plastic pipe installations, 
see Sec. 56.60-25(a).) Where plate insert pads are used, bolted 
connections shall have threads tapped into the plate to a depth of not 
less than the diameter of the bolt. If welded, the pipe or flange shall 
be welded to both sides of the plating. Openings in structure through 
which pipes pass shall be reinforced where necessary. Flanges shall not 
be bolted to bulkheads so that the plate forms a part of the joint. 
Metallic materials having a melting point of 1,700 [deg]F. or less are 
considered heat sensitive and if used must be suitably insulated.
    (b)(1) Pipes piercing the collision bulkhead shall be fitted with 
screwdown valves operable from above the bulkhead deck and the valve 
shall be fitted inside the forepeak tank adjacent to the collision 
bulkhead. The pipe penetrating the collision bulkhead shall be welded to 
the bulkhead on both sides. On new installations or replacement in 
vessels of 150 gross tons and over, the valve body shall be of steel or 
ductile cast iron.
    (2) Passenger vessels shall not have the collision bulkhead pierced 
below the margin line by more than one pipe conveying liquids in the 
forepeak tank except that if the forepeak tank is divided to hold two 
different kinds of liquids, the collision bulkhead may be pierced below 
the margin line by two pipes, provided there is no practical alternative 
to the fitting of the second pipe and further provided the safety of the 
vessel is maintained.
    (c) Valves and cocks not forming part of a piping system are not 
permitted in watertight subdivision bulkheads, however, sluice valves or 
gates in oiltight bulkheads of tankships may be used if approved by the 
Marine Safety Center.
    (d) Piping shall not be run over or in the vicinity of switchboards 
or other electrical equipment if avoidable. When such leads are 
necessary, welded joints only shall be used and provision shall be made 
to prevent leakage from damaging the equipment.
    (e) Stuffing boxes shall not be used on deep tank bulkheads, double 
bottoms or in any position where they cannot be easily examined. This 
requirement does not apply to ore carriers operating on the Great Lakes 
or cargo lines of oil tankers.
    (f) Piping systems shall be installed so that under no condition 
will the operation of safety or relief valves be impaired.

[[Page 194]]

    (g)(1) Power actuated valves in systems other than as specified in 
Sec. 56.50-60 of this part may be used if approved for the system by 
the Marine Safety Center. All power actuated valves required in an 
emergency to operate the vessel's machinery, to maintain its stability, 
and to operate the bilge and firemain systems must have a manual means 
of operation.
    (2)(i) Remote valve controls that are not readily identifiable as to 
service must be fitted with nameplates.
    (ii) Remote valve controls must be accessible under service 
conditions.
    (iii) Remote valve controls, except reach rods, must be fitted with 
indicators that show whether the valves they control are open or closed. 
Valve position indicating systems must be independent of valve control 
systems.
    (iv) Valve reach rods must be adequately protected.
    (v) Solid reach rods must be used in tanks containing liquids, 
except that tank barges having plug cocks inside cargo tanks may have 
reach rods of extra-heavy pipe with the annular space between the 
lubricant tube and the pipe wall sealed with a nonsoluble to prevent 
penetration of the cargo.
    (3) Air operated remote control valves must be provided with self-
indicating lines at the control boards which indicate the desired valve 
positions, i.e., open or closed.
    (h) Suitable drains shall be provided at low points of piping 
systems.
    (i) Valves and cocks shall be located so as to be easily accessible 
and valves or cocks attached to the shell of the vessel or to sea chests 
located below the floorplating shall be operable from above the 
floorplates.
    (j) When welded fabrication is employed, a sufficient number of 
detachable joints shall be provided to facilitate overhauling and 
maintenance of machinery and appurtenances. The joints shall be located 
so that adequate space is provided for welding, and the location of the 
welds shall be indicated on the plans.
    (k) Piping, including valves, pipe fittings and flanges, conveying 
vapors, gases or liquids whose temperature exceeds 150 [deg]F., shall be 
suitably insulated where necessary to preclude injury to personnel.
    (l) Where pipes are run through dry cargo spaces they must be 
protected from mechanical injury by a suitable enclosure or other means.

[CGFR 68-82, 33 FR 18843, Dec. 18, 1968, as amended by CGFR 69-127, 35 
FR 9978, June 17, 1970; CGD 77-140, 54 FR 40607, Oct. 2, 1989]