Self-regulating control valve

Abstract

A back pressure valve including a valve mechanism for controlling the flow of fluid from a pressurized system, a cylinder with a piston head therein and a spring acting to force the piston head in a close direction, the spring having a pressure force. The valve also includes a sample fluid line directing a sample fluid from the pressurized system to a first side of the cylinder, the sample fluid acting on the piston head in an open direction for the valve mechanism and supply pressure fluid acting on the piston head in a close direction for the valve mechanism. The max pressure for the fluid in the pressurized system is approximately equal to the pressure of the supply pressure fluid and the pressure force of the spring. A method including the steps of feeding a back pressure valve a supply pressure fluid at a desired pressure in a direction to close a valve mechanism and feeding the back pressure valve a sample fluid from the pressurized system in a direction to open the valve mechanism. The method also includes the step of opening the valve mechanism of the back pressure valve when pressure of fluid in the pressurized system reaches a max pressure.

Dependencies are inferred from the claim text.