PILOT TYPE ON-OFF VALVE AND BACK FLOW CHECK DEVICE HAVING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a pilot type on-off valve that can be manufactured more simply and at lower price than ever and moreover to be excellent in back flow check property.SOLUTION: A bleeding valve body 6 of a pilot type on-off valve vI is attached to a diaphragm plate 5 by fitting an open hole in a projection 56 provided on the diaphragm plate 5 and by causing insertion into the periphery of the open hole in an undercut portion 57 provided in the projection 56; a part of the bleeding valve body 6 can contact with and detach from the periphery of a back pressure chamber side opening part 52a of a bleeding hole 52 in accordance with the pressure of a primary side channel 11 and the bleeding hole 52; a clearance dimension Lc between an inner wall surface of the undercut portion 57 in an extruding direction of the projection 56 and the bleeding valve body 6 is ununiform; and a gap dimension of the bleeding hole side portion is smaller than those of other portions.SELECTED DRAWING: Figure 1