OVERFLATESTYRT SIKKERHETSVENTIL-ARRANGEMENT.

摘要

Disclosed is a tubing retrievable surface controlled subsurface safety valve having provisions for blocking communication of control fluid to the valve's pressure responsive operator and for locking the valve open in the event of valve failure. This abstract of the disclosure is neither intended to define the scope of the invention which, of course, is measured by the claims nor is it intended to limit the invention in any way.