Servo-controlled diaphragm cut=off valve - has auxiliary bore partly closed by diaphragm when valve bore is open

摘要

The valve has a large flow capacity. The auxiliary control bore in the housing is shut off by a valve controlled independently of the main diaphragm. The auxiliary bore (13) in the outlet (12) is positioned so that, when the valve is open, the bore may be partly closed, depending upon the diaphragm position. The bore ends in the pressure chamber on the side of the plate (5) carrying the diaphragm (4), away from the valve opening in an annular channel. The diaphragm plate can be of truncated cone section with a recess (8), in the side furthest from the diaphragm, provided with a guide boss (6) enclosed by a return spring. There is an annular sealing face (19) outside the recess.