Plastic Pipes Conference Association # 1995 Edinburgh
Wilson
The &ect of pipe wall thickness and welding parameters on the joint quality of bun fusion welded PElOO water pipes has been investigated using notched Charpy impact testing and tensile testing. The conventional U.K. Water Industry weld tensile test does not give a geometry independent measurement of weld ductility but is influenced by pipe wall thickness. The thicker walled pipes give weld ductility values apparently significantly lower than those of the thinner walled pipe welds. By using Charpy impact testing a wide range of wall thicknesses have been investigated with a constant specimen geometry. Impact testing has the added advantage that samples can be notched at selective positions in the weld zone thereby yielding more information about the weld smchlre. Impact test results confirm that a uniform weld quality can be maintained over the wall thickness range of 12 to 60mm found with these pipes. A modified weld tensile test method has been developed which gives equivalent corresponding weld ductility values for this wall thickness range veriiying the quality of welds in thick walled PElOO pipes when produced using the new recommended welding procedures.
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