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:
Aug. 05, 1980
Filed:
Jun. 28, 1979
Donald F Hallden, Garland, TX (US);
Clifford M Peters, Longview, TX (US);
L V McCary, Jr, Longview, TX (US);
W-K-M Wellhead Systems, Inc., Shreveport, LA (US);
Abstract
An electro-pneumatic or electro-hydraulic safety system for shutting in a well or the like in the event of unusual pressure conditions in the production line of the well. The safety system includes a pressure transducer (30) which senses the flowline pressure and provides a corresponding electrical signal to a digital controller (34). When the signal applied to the controller is outside of a preset range defined between low and high settings of the controller, a control circuit deenergizes a solenoid valve which bleeds fluid from a fluid actuator in order to close a surface safety valve (10). Once the safety valve has closed, the controller is latched out of service and must be manually reset before the safety valve can be opened. For protection of a subsurface safety valve (155), the safety system provides a time delay between opening of the subsurface valve and opening of the surface valve and also between closing of the surface valve and closing of the subsurface valve.