Electrically testable plastic pipe jointing for underground water - is sealed at two sepd. points by compression of elastic rings into grooves when bevelled ends of pipe encounter collar of sleeve

摘要

The ends (16) of sections of a plastic pipe (17) of poor conductivity are screwed into both sides of a jointing sleeve (10) which has threaded sections (12) on both sides of a central collar (11) with a sealing ring (13) at each face. A plane surface (18) on each pipe section abuts against the collar while a bevelled surface (19) compresses the sealing ring on its groove. A second seal is established by another ring (22) pressed into a groove (21) in the threaded portion (20) of the bevel by the cylindrical surface (14) of the sleeve. Resistance measurement can be performed with a focused electrical log. ADVANTAGE - Inadequately sealed joints can be distinguished unambiguously and rectified before the borehole is filled-in.