INTERNAL SAFETY VALVE AND PUMP SYSTEM

摘要

An internal valve and metered positive displacement pump for a pressure fluid tank. The tank defines a fluid compartment, and first and second vessels are positioned within the protective envelope of the tank. A bellows pump assembly disposed in the first vessel includes a bellows and a piston cylinder arrangement positioned within and attached to the bellows. Pressurized fluid is pumped into and out of the first vessel to actuate the piston cylinder arrangement. With this actuating movement fluid is pumped from the compartment through a valve in the second vessel and into the second vessel for removal therefrom. The valve is normally closed against the working pressure of the fluid in the compartment by a spring bellows relief assembly in the second vessel. The force of the fluid pump by the piston cylinder arrangement opens the valve, and a check valve pre- vents fluid from flowing back from the valve into the first vessel. A passageway through the first vessel allows the pressurized fluid in the compartment to bear on the bellows and thereby bias the piston cylin- der arrangement to an up (or down) position.