To provide a pilot type on-off valve which prevents a water shutoff failure by preventing air from remaining in a back-pressure chamber even when the back-pressure chamber is brought into an attitude positioned on the upper side of a diaphragm valve.
This pilot type on-off valve is provided with: an inflow chamber 6; an outflow passage 7; the diaphragm valve 8 opening/closing a valve seat 5 communicating with the outflow passage 7; the back-pressure chamber 10 formed on the back side of the diaphragm valve 8; an orifice 13 making the inflow chamber 6 communicate with the back-pressure chamber 10; a communication hole 11 making the back-pressure chamber 10 communicate with the outflow passage 7; and a pilot solenoid valve 12 opening/closing a pilot hole 24 interlaid in the communication hole. One end of the communication hole 11 is opened at a side position of the diaphragm valve 8 in the back-pressure chamber 10. When the back-pressure chamber 10 is brought into an attitude located at the upper-side position of the diaphragm valve 8, an inside wall surface of the back-pressure chamber 10 facing the diaphragm valve 8 is formed into an inclined surface 9a inclined in a direction gradually ascending toward an opening 11a of the communication hole 11.
| JP2003130248A | 2003-05-08 | |||
| JPS6021950U | 1985-02-15 | |||
| JPH0272084A | 1990-03-12 | |||
| JPS5779230A | 1982-05-18 |
Susumu Hori
Takeshi Sagi
Kenichi Homma
Tsuyoshi Kagaya
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