Pipe union without screw threads - has internal sleeve expanded by pressure on destructible diaphragms in rings forced along tapering bores

摘要

An internal sleeve (1) consists of a central section (3) of the same outside dia. as the pipes (20, 21) and two end sections, which have outside dia. slightly less than the inside dias. of the pipes. The sleeve has two slightly conical bores contacting as the axial distance from the centre increases and ending in inturned flanges (9, 11). Slightly conical rings are inserted in each branch of the bore and each is fitted with a thin closing diaphragm. A tapping (17) in the sleeve gives access to the space between the rings. To make the joint, either fluid pressure applied to the tapping, or an explosive charge is used to force the rings apart. This in turn expands the ends of the sleeve until they grip the pipes internally. The diaphragms may be water soluble or inflammable so that they can easily be destroyed when the joint has been made.