SEISMICALLY ACTIVATED GAS SHUT-OFF VALVE

摘要

A gas shut-off valve assembly designed to automatically close gas flow in a gas conduit in response to a seismic vibration comprises a trigger mechanism disposed in a trigger mechanism housing, a springless sealing mechanism disposed in a valve housing, a latching mechanism configured to engage the springless sealing mechanism to keep the gas conduit open, and a pressure release valve. Upon sensing a seismic vibration, the trigger mechanism disengages the springless sealing mechanism from the latching mechanism. Simultaneously, the springless sealing mechanism swings down and rotates around an axis by gravitational force to close off gas flow in the conduit. To reopen gas flow, the pressure release valve is actuated to relieve accumulated gas pressure inside the valve housing and the springless sealing mechanism is manually reset to its original open position.

主权项

1. A seismically activated gas shut-off valve assembly adapted to automatically maintain a gas conduit in a closed position in response to a seismic vibration comprising:
a trigger mechanism disposed in a trigger mechanism housing, further comprising a weight platform, a weight, and a vertically movable trigger bar initially in an upward position, wherein the weight is initially positioned on the weight platform; a flapper assembly rotatable around a horizontal axis and disposed in a valve housing; a latching mechanism configured to engage the flapper assembly to initially maintain the flapper assembly in an open position and support the trigger bar in the upward position; and a pressure release valve with operating means located outside of the valve housing, wherein upon a seismic vibration, the weight is vertically displaced from the weight platform onto the trigger bar, thereby pushing the trigger bar downward to force the latching mechanism to disengage the flapper assembly and allow the flapper assembly to rotate downward and close off gas flow until the pressure release valve is manually actuated and the flapper assembly is manually reset to its original open position.