Valve for maintaining constant back pressure - has pressure actuated diaphragm separating supply pressure chamber and feed chamber

摘要

The valve (3) maintains a constant back pressure in the supply of a fluid to a metering valve. The valve body (4) is divided into two chambers (9) connected by the circular opening (15). A cover (5) is screwed to the side of the body (4) and is provided with a flexible diaphragm (6) which fits over the opening. The cover is provided with an inlet (12) which is connected by the pipe (13) to a pressure source. The valve thus remains closed until the pressure underneath the diaphragm balances the pressure in the chamber (14) in the cover. A constant back pressure is thus maintained in the supply to the metering valve.