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:
Sep. 23, 1997
Filed:
Sep. 17, 1996
Lester B Engelmann, Woodland, CA (US);
Ames Company, Inc., Woodland, CA (US);
Abstract
An apparatus and method for automatic disablement of a pressure relief valve used in connection with a backflow preventer in a fire line. A normally open solenoid valve is included in a pressure sampling line, extending from an inlet, or upstream chamber to one side of the pressure relief valve. A water flow switch, interconnected to a power supply and the solenoid valve, is provided in the fire line. In response to water flowing through the fire line, the switch conducts, actuating the solenoid to a closed position. The solenoid thereby hydraulically isolates the inlet sensor line leading to the pressure relief valve. By maintaining high pressure in this portion of the sensor line, the pressure relief valve is effectively disabled. Thus, even if a check valve malfunction occurs, the pressure relief valve will not open and cannot cause a catastrophic loss of water pressure in the fire line.