A collar for electrically insulating between upper and lower tubing sections in which load bearing insulating materials in the collar are isolated from fluids both interior and exterior the collar.
申请公布号
US4861074(A)
申请公布日期
1989.08.29
申请号
US19880190780
申请日期
1988.05.06
申请人
PRODUCTION TECHNOLOGIES INTERNATIONAL INC.
发明人
EASTLUND, BERNARD J.;SCHMITT, KENNETH J.;ANDERSON, DOUGLAS C.
