Preliminary Development of a Composite Pipe Tee-Joint Using Heat Coupling Technology

Preliminary study of a composite pipe Tee-joint using heat coupling technology was conducted in this paper. The cutting process of the pipes for the Tee-joint was developed. Because the cutting edges of the pipes were coarse, it is necessary to smooth them. Both epoxy resin and prepreg were applied to the joined areas of the pipes. Shrink tape was also applied to the outside of the prepreg to add pressure and compression force. An optimized cure cycle for the epoxy prepreg used as the bonding materials was determined from the thermal cure analysis. The cure process of the joined pipes by epoxy prepreg was conducted in a specially designed oven. The total cure time was about 138 minutes. Several factors, including the thickness and length of the prepreg applied and the adhesive applied to the joints, have been considered in designing Teejoints. The hydrostatic pressure test results showed that the thickness of the wrapped epoxy prepreg had a very important effect on the quality of the joined pipes in terms of pressure.