| 摘要 |
<p>A firecheck to be installed in a combustible fuel line. The firecheck includes a casing having a gas inlet and an outlet and a burner screen is located between the inlet and outlet. A main control valve is disposed at the inlet and is biased to the closed position by a spring loaded arm. The control valve can be manually opened by a hand knob which operates through a drive mechanism, including two clutch units, and the valve is locked in the open position by a ratchet mechanism. One clutch unit can be manually disengaged to permit the control valve to close under the biasing force of the spring loaded arm, while the second clutch unit is disengaged to effect closing of the control valve by deflection of a bimetallic element located downstream and adjacent the burner screen. The outlet of the casing is provided with a pair of windows, each of which is adapted to be closed by a pivotable gate. On a detonation downstream the shock wave acts to pivot the gates to the closed position to retard the propagation of the shock wave and flame, and the flame will burn on the downstream side of the screen heating the bimetallic element to thereby close the main control valve and shut off the flow of the combustible fuel mixture.</p> |
