| 摘要 |
A dry pilot actuator provides for a high liquid to gas trip ratio. The actuator includes a housing having an interior surface defining an internal chamber with a central axis. The valve further includes a first inlet port; a second pilot port and a third drain port, each in communication with the internal chamber. A first actuator seat is disposed along the interior surface of the housing circumscribed about the central axis and a second actuator seat is circumscribed about the first actuator seat. A seal member having a sealed position and an open position is substantially aligned with the central axis of the housing in each of the sealed and open positions. The third port is isolated from the first and second port when the sealing member is in the sealed position, and in fluid communication with the first port when the sealing member is in the open position. The second port is isolated from the first and third ports when the sealing member is in the actuated position. A spring member biases the seal member toward the open position. |
