46 CFR § 153.980
Isolation of automatic closing valves
April 15, 2021
The person in charge of cargo transfer may isolate automatic closing valves described in §153.408(b) from a cargo containment system if the following conditions are met:
(a) The containment system carries products to which §153.408 does not apply.
(b) The valves are isolated by:
(1) Removing the valves; or
(2) Installing removable pipes and blind flanges to by-pass the valves.
[CGD 78-128, 47 FR 21211, May 17, 1982]