PRESSURE REGULATING VALVES

摘要

A pressure regulating system valve comprises a valve having a valve body with a control chamber and a regulated pressure chamber with a first diaphragm separating the two chambers, the first diaphragm being connected to a second diaphragm for movement therewith, and a valve member which co-acts with a valve seat to form a valving means between a pressure supply and the regulated pressure chamber. Movement of the diaphragms causes actuation of the valve seat to control pressure admitted from the pressure supply into the regulated pressure regulating chamber. In combination with the pressure regulating valve is a pressure relief valve which has a relief valve member exposed on one surface to the pressure in the regulated pressure chamber and on the opposite surface to atmospheric pressure and which has a spring to bias the relief valve member to a closed position so that an increased vacuum in the regulated pressure chamber moves the relief valve member to admit atmospheric air to the regulated pressure chamber. A safety valve operable in the event of excessively high vacuum is also provided. An auxiliary valve controlled by the vacuum control pressure in the central chamber which actuates the diaphragms.