| 摘要 |
<p>An automatic drain valve for discharging accumulations of fluids and foreign materials from a fluid handling system. The drain valve (10) comprises a reservoir (14) defining a reservoir volume (15) and a thru-port (28), in fluid communication with the reservoir volume (15), that defines an inlet (30) and terminates in a drainage valve (82) for flowthrough communications with a fluid handling system. An actuating mechanism selectively actuates a valve operator. In the preferred embodiment, a pilot valve (41) is mounted in the reservoir (14) for selectively communicating pressurized air to a valve operator (57), such that the valve operator selectively opens and closes the drainage valve (82) communicating with the outlet (88) of the reservoir (14) for selectively draining the reservoir. The pilot valve (41) includes a sensor tube (42) which defines a valve seat (44) and includes a magnetized valve plug (46) for selectively engaging the valve seat (44), the valve plug (46) having a selected magnetic polarity. A level sensing float (52) disposed within the reservoir (15) carries an annular magnet (56) normally having a polarity opposing that of the valve plug (46) such that the annular magnet (56) acts upon the valve plug (46) selectively opening and closing the pilot valve (81) as the float (52) rises and falls from a raised position to a lower position with the level of liquid within the reservoir (14).</p> |
