Abstract: A system for providing differential pressure relief in vessels having a cargo tank, incorporating an inert gas biased pressure/vacuum relief valve is disclosed. A source of inert gas, under controlled pressure and flow rate is connected to a vacuum outlet of a pressure/vacuum valve to bias the valve so that a desired pressure differential across the tank can be maintained during normal operations and easily changed and so that the valve will open at two different desired pressure differentials. A rupture disk connected to the vacuum pump adaptor is set to rupture at a desired pressure differential across the disk to allow atmospheric pressure to reach the vacuum outlet in the event of a rupture. A vacuum pump replaces the rupture disk to maintain a desired pressure differential across the pressure/vacuum valve, so as to reduce the amount of cargo that would leak from the damaged tank.

Abstract: An apparatus provides additional safety during the launching of survival craft from a ship or platform by which it is attached. A safety strop is comprised of a connecting line which is attached at its upper end to a means for lowering a launch pendant and a lifeboat. the lifeboat is equipped with an on load release means for launching it. The lower end of the connecting line is attached to a released means such as a shackle or a pelican hook. The connecting line release means is releaseably connected to a hang off lug assembly, which is attached to the on load release means. The connecting line has a longer length than the launch pendant, so that no load is carried by the connecting line unless the lifeboat is prematurely released from the launch pendant.