[Code of Federal Regulations]
[Title 46, Volume 1]
[Revised as of Octobery 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 46CFR38.10-15]

[Page 495]
 
                           TITLE 46--SHIPPING
 
         CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY
 
PART 38_LIQUEFIED FLAMMABLE GASES--Table of Contents
 
     Subpart 38.10_Piping, Valves, Fittings, and Accessory Equipment
 
Sec. 38.10-15  Safety relief valves--TB/ALL.

    (a) Each tank shall be fitted with or (subject to approval by the 
Commandant) connected to one or more safety relief valves designed, 
constructed and flow tested for capacity in conformance with subpart 
162.017 or 162.018 of subchapter Q (Specifications) of this chapter.
    (b) Safety relief valves conforming to subpart 162.017 of subchapter 
Q (Specifications) of this chapter may be used on tanks for a maximum 
pressure of 10 pounds per square inch gage. Safety relief valves 
conforming to subpart 162.018 of subchapter Q (Specifications) of this 
chapter may be used for any pressure.
    (c) The safety relief valves shall have a combined relieving 
capacity to discharge the greater of the following with not more than 20 
percent rise in pressure (in the tank) above the maximum allowable 
pressure:
    (1) The vapors evaporated by an embient air temperature of 115[deg] 
F. plus the maximum flow rate of the cargo filling pipes or,
    (2) The vapors generated under fire exposure computed using the 
formulas of Sec. 54.15-25(c) of subchapter F (Marine Engineering) of 
this chapter.
    (d) The safety relief valves shall meet the arrangement and 
inspection requirements of Sec. 54.15-25 of subchapter F (Marine 
Engineering) of this chapter.
    (e) Means shall be provided to protect nonpressure vessel tanks from 
excessive external pressure.
    (f) Void spaces between the primary and secondary barriers of 
nonpressure vessel type tanks shall be protected by relief devices. The 
relief setting shall not be higher than the void test pressure, and 
shall not exceed 90 percent of the setting of the safety relief valve 
protecting the primary tank.

[CGFR 68-82, 33 FR 18807, Dec. 18, 1968]