Diaphragm valve

Claim 1

A valve for controlling the flow of fluids by a low pressure gradient comprising: at least two fluid flow lines and a valve body contained within said flow lines and surrounded by flow fluid; said valve body interconnecting said lines and having an interior passage communicating with one of said flow lines and an exterior passage communicating with the other of said flow lines; said interior passage defined by a wall member having an end which forms a valve seat; said valve body including a sealed chamber disposed opposite said valve seat; said chamber formed on one side by a resilient diaphragm; said diaphragm spaced from and parallel to the plane of said valve seat and extending across both of said passages; and a gas under selected constant pressure in said chamber for selectiveLy positioning said diaphragm, whereby flow between said two lines may occur under appropriate pressure differential when the pressure in each of said lines is equal to or greater than said selected pressure and said flow will be prevented when the pressure in one of said lines is less than said selected pressure and in the other line is not greater than said selected pressure.

Claim 4

A device for controlling fluid flow by a small pressure gradient comprising: a valve body contained within and adapted to permit flow of fluid between at least two interconnected flow lines, said valve body including a plenum portion where flow interchange occurs and a pressurized portion where a selected control pressure is maintained; a diaphragm in said valve body adapted to prevent flow between said flow lines under selected conditions; said plenum portion formed by an inner collar, the wall of said valve body and said diaphragm; the end of said collar forming a valve seat and said diaphragm spaced a selected distance from and parallel to the plane of said valve seat; said diaphragm seating against said valve seat under selected pressure conditions in said flow lines and in said pressurized portion; and pressure control means and means connecting said pressure control means to said pressurized portion, whereby selection of pressure in said pressurized portion may prevent flow or permit flow between said flow lines under an appropriate pressure differential.

Claim 5

A device for controlling fluid flow by a small pressure gradient comprising: a valve body contained within and adapted to permit flow of fluid between at least two interconnected flow lines, said valve body including a plenum portion where flow interchange occurs and a pressurized portion where a selected control pressure is maintained; a diaphragm in said valve body adapted to prevent flow between said flow lines under selected conditions; said plenum portion formed by an inner collar, the wall of said valve body and said diaphragm; the end of said collar forming a valve seat and said diaphragm spaced a selected distance from and parallel to the plane of said valve seat; said diaphragm seating against said valve seat under selected pressure conditions in said flow lines and in said pressurized portion; and pressure control means and means connecting said pressure control means to said pressurized portion, whereby selection of pressure in said pressurized portion may prevent flow or permit flow between said flow lines under an appropriate pressure differential.