Diaphragm valve

Abstract

The present invention addresses the problem of providing a diaphragm valve which has a simple configuration, effectively prevents the generation and accumulation of reaction products in a valve body seal part, suppresses occlusion during valve closing, and thus can satisfactorily maintain the isolation properties of the valve even after multiple times of opening and closing and long-term use. Thediaphragm valve has a structure in which a diaphragm piece and a piece holder for holding a conical piece are coupled in a valve housing, the outer peripheral edge of an inner diameter opening of thediaphragm is clamped by the piece holder and the diaphragm piece, the diaphragm piece is held by a bonnet so as to be capable of moving up and down, and the bonnet and the outer peripheral edge of thediaphragm are clamped so that the piece is suspended from the diaphragm. The diaphragm valve is provided with a conical sealing part formed on the conical surface of the piece and a cut-off valve seat part formed on the primary side opening edge of the valve box, reaction products generated on the conical sealing part are cut off through sliding movement of the piece, and the conical sealing partis sealed through the cut-off valve seat part.

Description

technical field [0001] The present invention relates to a diaphragm valve, and more particularly to a diaphragm valve used as an automatic or manual on-off valve in semiconductor manufacturing equipment. Background technique [0002] Generally speaking, the gas piping system in semiconductor manufacturing equipment is composed of a gas supply system for the process chamber and a gas exhaust system. In order to meet the characteristic requirements such as area, the sliding part is small, the dead zone is minimized, and the structure is easy to meet the high gas displacement and cleanability of the diaphragm valve (especially the direct touch type). [0003] Various types of such valves have been proposed, and there are valves shown in Patent Documents 1 to 3, for example. Patent Document 1 is a direct touch type. Its ring-shaped valve seat is fixed on the edge of the opening of the primary side flow path. The diaphragm is clamped on the upper part of the valve seat. When the...

AI Technical Summary

Problems solved by technology

[0016] However, in the conventional diaphragm valves including Patent Documents 1 to 3, the valve itself cannot do anything to deal with the above-mentioned problems caused by the presence of reaction products on the sealing surface between the valve body and the valve seat.

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