49 C.F.R. § 178.347-4 Pressure relief.
Title 49 - Transportation
(a) Each cargo tank must be equipped with a pressure and vacuum relief system in accordance with §178.345–10 and this section. (b) Type and Construction. Vacuum relief devices are not required for cargo tanks designed to be loaded by vacuum or built to withstand full vacuum. (c) Pressure settings of relief valves. The setting of pressure relief valves must be in accordance with §178.345–10(d). (d) Venting capacities. (1) The vacuum relief system must limit the vacuum to less than 80 percent of the design vacuum capability of the cargo tank. (2) If pressure loading or unloading devices are provided, the relief system must have adequate vapor and liquid capacity to limit the tank pressure to the cargo tank test pressure at maximum loading or unloading rate. The maximum loading or unloading rate must be included on the metal specification plate. [Amdt. 178–89, 54 FR 25030, June 12, 1989, as amended at 55 FR 37064, Sept. 7, 1990. Redesignated by Amdt. 178–112, 61 FR 18934, Apr. 29, 1996]
Title 49: Transportation
PART 178—SPECIFICATIONS FOR PACKAGINGS
Subpart J—Specifications for Containers for Motor Vehicle Transportation
§ 178.347-4 Pressure relief.
