HDPE Reinforced Electrofusion Coupler

HDPE Reinforced Electrofusion Coupler that are not injection moulded and do not have external reinforcement are likely to expand during fusion.  Coupler expansion increases the gap between the pipe and coupler, which reduces weld pressure in the joint. This leads to slow crack growth failure through the weld plane.  Slow Crack Growth, by its name, is slow and occurs over time (1-5 years), well beyond the joint successfully passing hydrostatic testing on site. DSD Appendix 5A Clause 5.6.13, requires non-injection moulded couplers to have a suitable form of external reinforcement to prevent expansion applied to the HDPE Reinforced Electrofusion Coupler as parts of it’s manufacture.