| 摘要 |
PROBLEM TO BE SOLVED: To prevent a diaphragm from being deformed into strain due to negative pressure generated in a secondary side passage when a valve is closed, and restrain the diaphragm from being damaged by stress concentration. SOLUTION: In a diaphragm valve structure, the abuttment of a diaphragm 2 against or the separation of the diaphragm from a valve seat 5 provided at the boundary between a primary side passage 3 and a secondary side passage 4, allows a space between the passages 3 and 4 to be closed or opened. The diaphragm valve structure is provided with a closing time membrane receiver 9 for receiving the membrane part 2b of the diaphragm 2 when the valve is closed. This valve structure is also provided with an opening time membrane receiver 8 for receiving the membrane part 2b of the diaphragm 2 when the valve is opened. Since both the membrane receivers 8 and 9 are made of plastics, self-lubricity is given to the surfaces of them. Therefore, when the valve is closed, the membrane part 2b of the diaphragm 2 is received by the closing time receiver 9, and the membrane part 2b will never be pulled into the secondary side passage 4 even if the pressure of the secondary passage 4 is dropped down.
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