5503.2.5 Arrangement.
FC § 5503.2.5
Pressure relief devices shall be arranged to discharge unobstructed, at rated capacity, to the outdoors in such a manner as to prevent escaping gas from impinging on personnel, cryogenic containers, equipment and adjacent structures or from entering enclosed spaces. Exception: United States Department of Transportation specification cryogenic containers with an internal volume of 2 cubic feet (0.057 m 3) or less. 5503.2.6 Shutoffs between pressure relief devices and cryogenic containers. Shutoff valves shall not be installed between pressure relief devices and cryogenic containers. Exception: A shutoff valve is allowed on cryogenic containers equipped with multiple pressure-relief device installations where the design and arrangement of the valves provide sufficient relief capacity for the pressure relief devices to prevent the MAWP of the cryogenic container or system from being exceeded at all times.
