1. Field of the Invention
The present invention relates to surface controlled subsurface safety valves used in the oil and gas industry and means for locking such valves in their open position.
2. Description of the Prior Art
The following U.S. patents disclose various inventions for locking surface controlled subsurface safety valves both temporarily and permanently in their open position:
U.S. Pat. Nos. 3,696,868; 3,882,935; 4,273,186; 4,276,937 and 4,344,602.
The present invention is particularly useful for temporarily locking open surface controlled subsurface safety valves having flapper type valve closure means such as shown in U.S. Pat. No. 3,845,818 to Thomas M. Deaton. This patent is incorporated by reference for all purposes within this application.