Testing of welded joints of polypropylene pipes

Previously, the technology of welding a heated tool into the socket of polypropylene pipes at negative ambient temperatures without the use of lightweight structures was proposed. To check the efficiency of the developed welding technology, the welded socket joints were tested in accordance with the recommended current standards. It is shown that the resistance tests at a constant internal pressure, hydraulic tests and static separation tests don’t reveal a violation of welding technology into the socket of polymeric pipes and don't give a quantitative assessment of strength. Compression shear tests of ring samples of welded joints can determine the breaking stress. However, the results showed that the values of the critical stress of welded joints, obtained with welding technology failures aren't lower than the same values of welded joints made in compliance with all the requirements for welding into the socket of polymeric pipes.