Patent ID: 6382244
Filing Date: 2002-05-07
Classification: E21B,Y10T

Abstract:
A circular check valve comprising:a lower housing having a first central axial aperture, an upper housing having a second central axial aperture connected to said lower housing, valve means for controlling flow of fluid incorporating a third central axial aperture sandwiched between said upper and lower housings such that said central axial apertures are axially aligned with and in communication with each other thereby axially forming a continuous conduit through said lower housing, said valve means, and said upper housing, an external member axially passing through said continuous conduit, first seal means located in said upper housing for effecting a fluid seal between said upper housing and said external member, second seal means located in said lower housing for effecting a fluid seal between said lower housing and said external member, and third seal means located in said valve means for effecting a fluid seal between said valve means and said external member.