[Code of Federal Regulations]
[Title 46, Volume 7]
[Revised as of October 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 46CFR181.410]

[Page 262-265]
 
                           TITLE 46--SHIPPING
 
   CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED)
 
PART 181--FIRE PROTECTION EQUIPMENT--Table of Contents
 
        Subpart D--Fixed Fire Extinguishing and Detecting Systems
 
Sec. 181.410  Fixed gas fire extinguishing systems.

    (a) General. (1) A fixed gas fire extinguishing system aboard a 
vessel must be approved by the Commandant, and be custom engineered to 
meet the requirements of this section unless the system meets the 
requirements of Sec. 181.420.
    (2) System components must be listed and labeled by an independent 
laboratory. A component from a different system, even if from the same 
manufacturer, must not be used unless included in the approval of the 
installed system.
    (3) System design and installation must be in accordance with the 
Marine Design, Installation, Operation, and Maintenance Manual approved 
for the system by the Commandant.
    (4) A fixed gas fire extinguishing system may protect more than one 
space. The quantity of extinguishing agent must be at least sufficient 
for the space requiring the greatest quantity as determined by the 
requirements of paragraphs (f)(4) and (g)(2) of this section.
    (b) Controls. (1) Controls and valves for operation of fixed gas 
fire extinguishing system must be:
    (i) Located outside the space protected by the system; and
    (ii) Not located in a space that might be inaccessible in the event 
of fire in the space protected by the system.
    (2) Except for a normally unoccupied space of less than 170 cubic 
meters (6000 cubic feet), release of an extinguishing agent into a space 
must require two distinct operations.
    (3) A system must have local manual controls at the storage 
cylinders capable of releasing the extinguishing agent. In addition, a 
normally manned space must have remote controls for releasing the 
extinguishing agent at the primary exit from the space.
    (4) Remote controls must be located in a breakglass enclosure to 
preclude accidental discharge.
    (5) Valves and controls must be of an approved type and protected 
from damage or accidental activation. A pull cable used to activate the 
system controls must be enclosed in conduit.
    (6) A system protecting more than one space must have a manifold 
with a normally closed stop valve for each space protected.
    (7) A gas actuated valve or device must be capable of manual 
override at the valve or device.
    (8) A system, that has more than one storage cylinder for the 
extinguishing agent and that relies on pilot cylinders to activate the 
primary storage cylinders, must have at least two pilot cylinders. Local 
manual controls, in compliance with paragraph (b)(3) of this section, 
must be provided to operate the pilot cylinders but are not required for 
the primary storage cylinders.
    (9) A system protecting a manned space must be fitted with an 
approved time delay and alarm arranged to require the alarm to sound for 
at least 20 seconds or the time necessary to escape from the space, 
whichever is greater, before the agent is released into the space. 
Alarms must be conspicuously and centrally located. The alarm must be 
powered by the extinguishing agent.
    (10) A device must be provided to automatically shut down power 
ventilation serving the protected space and engines that draw intake air 
from the protected space prior to release of the extinguishing agent 
into the space.
    (11) Controls and storage cylinders must not be in a locked space 
unless the key is in a breakglass type box conspicuously located 
adjacent to the space.
    (c) Storage space. (1) Except as provided in paragraph (c)(2) of 
this section, a storage cylinder for a fixed gas extinguishing system 
must be:
    (i) Located outside the space protected by the system; and
    (ii) Not located in a space that might be inaccessible in the event 
of a fire in the space protected by the system.
    (2) A normally unoccupied space of less than 170 cubic meters (6,000 
cubic feet) may have the storage cylinders located within the space 
protected. When the storage cylinders are located in the space:

[[Page 263]]

    (i) The system must be capable of automatic operation by a heat 
actuator within the space; and
    (ii) Have manual controls in compliance with paragraph (b) of this 
section except for paragraph (b)(3).
    (3) A space containing a storage cylinder must be maintained at a 
temperature within the range from -30[deg] C (-20[deg] F) to 55[deg] C 
(130[deg] F) or at another temperature as listed by the independent 
laboratory and stated in the manufacturer's approved manual.
    (4) A storage cylinder must be securely fastened, supported, and 
protected against damage.
    (5) A storage cylinder must be accessible and capable of easy 
removal for recharging and inspection. Provisions must be available for 
weighing each storage cylinder in place.
    (6) Where subject to moisture, a storage cylinder must be installed 
to provide a space of at least 51 millimeters (2 inches) between the 
deck and the bottom of the storage cylinder.
    (7) A Halon 1301 storage cylinder must be stowed in an upright 
position unless otherwise listed by the independent laboratory. A carbon 
dioxide cylinder may be inclined not more than 30[deg] from the 
vertical, unless fitted with flexible or bent siphon tubes, in which 
case they may be inclined not more than 80[deg] from the vertical.
    (8) Where a check valve is not fitted on an independent storage 
cylinder discharge, a plug or cap must be provided for closing the 
outlet resulting from storage cylinder removal.
    (9) Each storage cylinder must meet the requirements of Sec. 147.60 
in subchapter N of this chapter, or other standard specified by the 
Commandant.
    (10) A storage cylinder space must have doors that open outwards or 
be fitted with kickout panels installed in each door.
    (d) Piping. (1) A pipe, valve, or fitting of ferrous material must 
be protected inside and outside against corrosion unless otherwise 
approved by the Commandant. Aluminum or other low melting material must 
not be used for a component of a fixed gas fire extinguishing system 
except as specifically approved by the Commandant.
    (2) A distribution line must extend at least 51 millimeters (2 
inches) beyond the last orifice and be closed with a cap or plug.
    (3) Piping, valves, and fittings must be securely supported, and 
where necessary, protected against damage.
    (4) Drains and dirt traps must be fitted where necessary to prevent 
the accumulation of dirt or moisture and located in accessible 
locations.
    (5) Piping must be used for no other purpose except that it may be 
incorporated with the fire detecting system.
    (6) Piping passing through accommodation spaces must not be fitted 
with drains or other openings within such spaces.
    (7) Installation test requirements for carbon dioxide systems. The 
distribution piping of a carbon dioxide fixed gas extinguishing system 
must be tested as required by this paragraph, upon completion of the 
piping installation, using only carbon dioxide, compressed air, or 
nitrogen gas.
    (i) Piping between a storage cylinder and a stop valve in the 
manifold must be subjected to a pressure of 6,894 kPa (1,000 psi), 
except as permitted in paragraph (d)(7)(iii) of this section. Without 
additional gas being introduced to the system, the pressure drop must 
not exceed 2,068 kPa (300 psi) after two minutes.
    (ii) A distribution line to a space protected by the system must be 
subjected to a test similar to that described in paragraph (d)(7)(i) of 
this section except the pressure used must be 4,136 kPa (600 psi). For 
the purpose of this test, the distribution piping must be capped within 
the space protected at the first joint between the nozzles and the 
storage cylinders.
    (iii) A small independent system protecting a space such as a paint 
locker may be tested by blowing out the piping with air at a pressure of 
not less than 689 kPa (100 psi) instead of the tests prescribed in the 
paragraphs (d)(7)(i) and (d)(7)(ii) of this section.
    (8) Installation test requirements for Halon 1301 systems. The 
distribution piping of a Halon 1301 fixed gas extinguishing system must 
be tested, as required by this paragraph, upon completion of the piping 
installation, using only carbon dioxide, compressed air, or nitrogen.

[[Page 264]]

    (i) When pressurizing the piping, pressure must be increased in 
small increments. Each joint must be subjected to a soap bubble leak 
test, and all joints must be leak free.
    (ii) Piping between the storage cylinders and the manifold stop 
valve must be subjected to a leak test conducted at a pressure of 4,136 
kPa (600 psi). Without additional gas being added to the system, there 
must be no loss of pressure over a two minute period after thermal 
equilibrium is reached.
    (iii) Distribution piping between the manifold stop valve and the 
first nozzle in the system must be capped and pneumatically tested for a 
period of 10 minutes at 1,034 kPa (150 psi). At the end of 10 minutes, 
the pressure drop must not exceed 10% of the test pressure.
    (e) Pressure relief. When required by the cognizant OCMI, spaces 
that are protected by a fixed gas fire extinguishing system and that are 
relatively air tight, such as refrigeration spaces, paint lockers, etc., 
must be provided with suitable means for relieving excessive pressure 
within the space when the agent is released.
    (f) Specific requirements for carbon dioxide systems. A custom 
engineered fixed gas fire extinguishing system, which uses carbon 
dioxide as the extinguishing agent, must meet the requirements of this 
paragraph.
    (1) Piping, valves, and fittings must have a bursting pressure of 
not less than 41,360 kPa (6,000 psi). Piping, in nominal sizes of not 
more than 19 millimeters (0.75 inches), must be at least Schedule 40 
(standard weight), and in nominal sizes of over 19 millimeters (0.75 
inches), must be at least Schedule 80 (extra heavy).
    (2) A pressure relief valve or equivalent set to relieve at between 
16,550 and 19,300 kPa (2,400 and 2,800 psi) must be installed in the 
distribution manifold to protect the piping from over-pressurization.
    (3) Nozzles must be approved by the Commandant.
    (4) When installed in a machinery space, paint locker, a space 
containing flammable liquid stores, or a space with a fuel tank, a fixed 
carbon dioxide system must meet the following requirements.
    (i) The quantity of carbon dioxide in kilograms (pounds) that the 
system must be capable of providing to a space must not be less than the 
gross volume of the space divided by the appropriate factor given in 
Table 181.410(f)(4)(i). If fuel can drain from a space being protected 
to an adjacent space or if the spaces are not entirely separate, the 
volume of both spaces must be used to determine the quantity of carbon 
dioxide to be provided. The carbon dioxide must be arranged to discharge 
into both such spaces simultaneously.

                         Table 181.410(f)(4)(i)
------------------------------------------------------------------------
                         Gross volume of space in cubic meters (feet)
       Factor        ---------------------------------------------------
                                Over                    Not Over
------------------------------------------------------------------------
      0.94 (15)       ........................          14 (500)
       1.0 (16)               14 (500)                  45 (1,600)
       1.1 (18)               45 (1,600)               125 (4,500)
       1.2 (20)              125 (4,500)              1400 (50,000)
       1.4 (22)             1400 (50,000)       ........................
------------------------------------------------------------------------

    (ii) The minimum size of a branch line to a space must be as noted 
in Table 181.410(f)(4)(ii).

                         Table 181.410(f)(4)(ii)
------------------------------------------------------------------------
  Maximum quantity of carbon dioxide     Minimum nominal pipe size  mm
          required  kg (lbs)                        (inches)
------------------------------------------------------------------------
             45.4 (100)                           12.7 (0.5)
              102 (225)                             19 (0.75)
              136 (300)                             25 (1.0)
              272 (600)                             30 (1.25)
              454 (1000)                            40 (1.5)
             1111 (2450)                            50 (2.0)
             1134 (2,500)                           65 (2.5)
             2018 (4,450)                           75 (3.0)
             3220 (7,100)                           90 (3.5)
             4739 (10,450)                         100 (4.0)
             6802 (15,000)                         113 (4.5)
------------------------------------------------------------------------

    (iii) Distribution piping within a space must be proportioned from 
the distribution line to give proper supply to the outlets without 
throttling.
    (iv) The number, type, and location of discharge outlets must 
provide uniform distribution of carbon dioxide throughout a space.
    (v) The total area of all discharge outlets must not exceed 85 
percent nor be less than 35 percent of the nominal cylinder outlet area 
or the area of the supply pipe, whichever is smaller. The nominal 
cylinder outlet area in square millimeters (inches) is determined by

[[Page 265]]

multiplying the factor 0.015 (0.0022 if using square inches) by the 
total capacity in kilograms (pounds) of all carbon dioxide cylinders in 
the system, except in no case must the outlet area be of less than 71 
square millimeters (0.110 square inches if using pounds).
    (vi) The discharge of at least 85 percent of the required amount of 
carbon dioxide must be completed within two minutes.
    (5) When installed in an enclosed ventilation system for rotating 
electrical propulsion equipment a fixed carbon dioxide extinguishing 
system must meet the following requirements.
    (i) The quantity of carbon dioxide in kilograms (pounds) must be 
sufficient for initial and delayed discharges as required by this 
paragraph. The initial discharge must be equal to the gross volume of 
the system divided by 160 (10 if using pounds) for ventilation systems 
having a volume of less than 57 cubic meters (2,000 cubic feet), or 
divided by 192 (12 if using pounds) for ventilation systems having a 
volume of at least 57 cubic meters (2,000 cubic feet). In addition, 
there must be sufficient carbon dioxide available to permit delayed 
discharges to maintain at least a 25 percent concentration until the 
equipment can be stopped. If the initial discharge achieves this 
concentration, a delayed discharge is not required.
    (ii) The piping sizes for the initial discharge must be in 
accordance with Table 181.410(f)(4)(ii) and the discharge of the 
required amount must be completed within two minutes.
    (iii) Piping for the delayed discharge must not be less than 12.7 
millimeters (0.5 inches) nominal pipe size, and need not meet specific 
requirement for discharge rate.
    (iv) Piping for the delayed discharge may be incorporated with the 
initial discharge piping.
    (6) When installed in a cargo space a fixed carbon dioxide 
extinguishing system must meet the following requirements.
    (i) The number of kilograms (pounds) of carbon dioxide required for 
each space in cubic meters (feet) must be equal to the gross volume of 
the space in cubic meters (feet) divided by 480 (30 if using pounds).
    (ii) System piping must be of at least 19 millimeters (0.75 inches).
    (iii) No specific discharge rate is required.
    (g) Specific requirements for Halon 1301 systems. (1) A custom 
engineering fixed gas fire extinguishing system, which uses Halon 1301, 
must comply with the applicable sections of UL Standard 1058 
``Halogenated Agent Extinguishing System Units,'' and the requirements 
of this paragraph.
    (2) The Halon 1301 quantity and discharge requirements of UL 1058 
apply, with the exception that the Halon 1301 design concentration must 
be 6 percent at the lowest ambient temperature expected in the space. If 
the lowest temperature is not known, a temperature of -18[deg] C (0[deg] 
F) must be assumed.
    (3) Each storage cylinder in a system must have the same pressure 
and volume.
    (4) Computer programs used in designing systems must have been 
approved by an independent laboratory.

    Note to Sec. 181.410(g):
    As of Jan. 1, 1994, the United States banned the production of 
Halon. The Environmental Protection Agency placed significant 
restrictions on the servicing and maintenance of systems containing 
Halon. Vessels operating on an international voyage, subject to SOLAS 
requirements, are prohibited from installing fixed gas fire 
extinguishing systems containing Halon.

[CGD 85-080, 61 FR 982, Jan. 10, 1996; 61 FR 20557, May 7, 1996, as 
amended at 62 FR 51358, Sept. 30, 1997; USCG-2000-7790, 65 FR 58465, 
Sept. 29, 2000]