| 摘要 |
A valve having a valve body formed with an internal orifice between the valve inlet and outlet ports, and a main valve member for opening and closing the orifice. A chamber above the valve member is supplied with high pressure fluid through a bleed passageway extending between the chamber and the inlet port. A pilot valve controls exhausting of the chamber when the main valve is to be opened. A flow control element in the bleed passageway maintains a constant rate of fluid flow for filling the chamber, to close the main valve, regardless of the pressure differential across the flow control element. The bleed passageway may be in either the valve body or the main valve member. The flow control element may be an annular rubber washer.
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