| 摘要 |
PROBLEM TO BE SOLVED: To prevent a main valve from being fixed to a main valve seat by forcibly opening the main valve in a cold region while lightly performing flow control operation by changing the opening of the main valve with the operation of a pilot valve. SOLUTION: This pilot flow control valve device comprises the main valve 16, a back pressure chamber 24, an introduction small hole 26, a pilot water passage 28, the pilot valve 30, and a drive shaft 42. The flow of a main water passage is controlled by advancing and retreating the main valve 16 according to the advancing and retreating motions of the pilot valve 30. A pilot valve case 35 is installed to be fixed to the main valve 16, and the drive force of the drive shaft 42 is exerted on the pilot valve 30 and the main valve 16 through the pilot valve case 35 when water is drained to forcibly open the main valve 16 in a closed state. COPYRIGHT: (C)2007,JPO&INPIT
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