Section 157.170 - COW equipment: Removal(a) Whenever a deck mounted COW machine is removed from the tank, the master shall ensure that: (1) The supply piping to that machine is blanked off; and(2) The tank opening is sealed by a secured plate made of steel or an equivalent material accepted by the Commandant.(b) If the equipment for the COW system is removed from a cargo tank for the carriage of cargoes other than crude oil and then reinstalled, the master shall ensure that, before COW operations are conducted, the system has no crude oil leakage.