| 摘要 |
<p>A device for controlling the delivery of a combustible gas to a burner apparatus comprises a main gas-delivery duct (2) in which there is at least one servo-assisted diaphragm valve (5) including a valve seat (5a) associated with a corresponding closure member (5b) with diaphragm control (6) for opening the seat against the action of a resilient biasing means (7), the diaphragm valve (5) comprising a respective control solenoid valve (8) with an electromagnetic operator for controlling the opening/closure of the corresponding valve (5), the solenoid valve being arranged to bring about the opening/closure of a duct (9) of a respective servo-assisted control circuit so as to operate the closure member (5b) of the valve (5) indirectly, by means of the diaphragm control, the duct of the control circuit putting a portion of the main duct (2) that is disposed upstream of the valve seat (5a) with respect to the direction of the gas-flow into flow communication with a respective control chamber (10) of the diaphragm valve, a first side (6a) of the diaphragm (6) of the diaphragm control being subjected to the pressure existing in the respective control chamber (10). The second, opposite side (6b) of the diaphragm (6) delimits a space (21) which is separated from the portion of the main duct (2)_that-" extends downstream of the valve seat so that the second side (6b) of the diaphragm is not subjected to the delivery pressure of the gas that is present in the said duct portion, downstream of the valve seat (5a).</p> |
