摘要 |
A direct touch type metal diaphragm valve, wherein durability of the valve, that is to say, the ensured number of continuous open/close operations of the valve, is substantially increased under conditions that an appropriate flow rate coefficient Cv is maintained, and changes of the afore-mentioned Cv value over time are mitigated by means of restricting the deformation of the valve seat over time. The afore-mentioned metal diaphragm is formed in a round, reverse-dish shape by laminating a plural number of thin stainless steel plates and a thin Nickel.Cobalt alloy plate, and its center part is bulged upward, and the maximum valve stroke of the valve is regulated to be 55% to 70% of the distance of the maximum bulge height &Dgr;h of the afore-mentioned metal diaphragm.
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