The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 01, 1984
Filed:
Aug. 05, 1981
Walter W Powell, Houston, TX (US);
Anderson, Greenwood & Co., Houston, TX (US);
Abstract
For use with a safety relief valve, a pilot valve is disclosed. The preferred and illustrated embodiment of the pilot valve incorporates a pressure moved spindle within a housing, the housing being drilled and incorporating a valve and valve seat mechanism. The device is adapted to be connected to a high pressure inlet source. In addition, it has a flow path from the inlet through a needle orifice. This needle orifice chokes the flow into an outlet port. The outlet is provided for controlling a safety relief valve. A third path past the valve element is included which conducts fluid to an exhaust port. A coil spring forms a force in one direction for the valve element while the inlet line pressure forms a force in the opposite direction. When the inlet pressure is sufficiently high, the valve element is moved, thereby opening the valve. This embodiment is enhanced by indicating the operative position which is monitored by a pressure driven differential area piston having a protruding plunger which provides an output indication indicative of the operative state of the valve.