| 摘要 |
A gas valve assembly has a main valve connected between the inlet and outlet and controlled by a diaphragm actuator. A two position control valve connects the upper side of the diaphragm to either the inlet gas pressure or the outlet gas pressure to open or close the main valve. A pressure responsive valve means responding to the outlet pressures, controls the exhausting of gas from the upper side of the diaphragm to regulate the outlet pressure. An orifice is contained in the inlet passage to the control valve so that when the control valve is in an on position, the flow of gas to the upper side of the diaphragm is restricted by the orifice. To insure an initial fast opening of the main valve to insure ignition of the combustion device, a flow control valve means is placed in series with the orifice to increase the flow rate of gas when the control valve is moved from the off to the on position to fill the chamber above the diaphragm quickly. The flow control valve closes as soon as the pressure builds up on the upper side of the diaphragm; however, the delay in the operation of the flow control valve provides for an initial fast opening of the valve means when the control valve is operated.
|
