Diaphragm valve

Abstract

Provided is a diaphragm valve which is capable of exhibiting a high flow and a stable high Cv value, by enabling an optimal flow path space corresponding to a prescribed Cv value to be formed withoutcompromising body strength, even if a valve body is made very compact. This diaphragm valve is provided with: a valve seat (52) provided in a valve chamber inside a body (50); an annular groove (53) provided around the outer circumference of the valve seat (52); a diaphragm (55) provided so as to be capable of being brought into contact with and separated from the valve seat (52) via a pressing means; and a primary-side flow path (56) which communicates with the valve chamber (51). The inner diameter (R) of a secondary-side flow path (57) connected to the annular groove (53) is 2.0-4.5 times the groove width (W) of the annular groove (53). The cross-sectional area (S) of an intersection between the annular groove (53) and the secondary-side flow path (57) is smaller than the cross-sectional area (T) of the secondary-side flow path (57). The cross-sectional area (S) of the intersection is set so as to be at least 35% of the cross-sectional area (T) of the secondary-side flow path (57),to obtain a prescribed Cv value.

Description

technical field [0001] The present invention relates to a diaphragm valve, and particularly relates to a diaphragm valve capable of exhibiting a stable high flow rate (high Cv value) while being very compact and miniaturized, and suitable for use, for example, in a gas supply system to a semiconductor manufacturing device. Background technique [0002] In general, a so-called direct contact type diaphragm valve is mainly used as a control valve of a gas supply system in a semiconductor manufacturing process. The advantages of the direct diaphragm valve are as follows: Since the valve seat is directly closed by the metal diaphragm used as a seal against the outside, it can constitute a very simple flow path without redundant parts in the gas contact part, Therefore, there is no sliding part between metals in the gas contact part, and it becomes the most suitable structure for cleaning the fluid. However, there is a limit to the stroke that can be ensured, and it is difficult...

AI Technical Summary

Problems solved by technology

This also brings about an increase in the cost of semiconductor manufacturing equipment, and there is a problem that the manufacturing cost of semiconductor products deteriorates.

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