Subsurface safety valves and seals

摘要

Subsurface safety valves of the tubing and wireline retrieveable types operated by a control fluid responsive annular piston in an annular cylinder sealed at opposite ends by a two-way static and dynamic metal-to-metal seal assembly which includes central Bellville loading washers, a spacer ring on each side of the loading washers, and a Bellville sealing washer at each end of the spacer rings. The metal-to-metal seals are useful in a number of applications requiring the sealing of pressurized spaces between spaced concentric parts.