| 摘要 |
<p>A combined manual and pressure-responsive shut-off valve, intended particularly for use with high pressure gas cylinders, is disclosed. The valve includes a single seat and a single plug, the plug having a first sealing surface for closing against a low residual pressure in the cylinder and a second sealing surface for closing against a relatively high cylinder pressure. A pressure-responsive actuator engages the first sealing surface against the seat whenever pressure in the cylinder falls below a predetermined minimum. A manual actuator engages the second sealing surface against the valve seat to close against a wide range of pressures. The seat is specifically configured to conform to the plug. Means are provided for refilling the cylinder without removing the combined valve. In one embodiment, a special tool is provided for opening the pressure-responsive actuator. In a second embodiment, a bypass check valve is provided to allow gas to flow into the cylinder.</p> |
