Lifetime Analysis-Modelling
Plastic Pipes Conference Association # 1995 Edinburgh
Grigory, O'Donoghue, Mamoun
Measurements of temperature, power input, and pressure of the molten PE at the pipe-coupling interface in 4-, 6-, and 8-inch (1 14-, 168- and 219-rnm)' electrofusion (EF) couplings were made using instrumented experiments during the fusion cycle. The high temperature properties of several medium and high density polyethylene (PE) resins used in U. S. pipe and couplings were also determined. These data sewed to validate a computer model of the fusion process in couplings for pipe sizes 2- through 8-inch diameter. The program can be used to identify an inadequate fusion and is of benefit both to manufacturers and utilities in the design of reliable joints. The confidence level for the model was enhanced by a broad p m t e r study of 2-, 4-, and 6-inch (60-, 114and 168- mm)diameter EF couplings from five U. S. and European manufacturers. A shear test was developed to evaluate the strength of the joints and sustained pressure tests were conducted to c o n f i model predictions of good and inadequate fusions. This paper presents the results of the experiments performed on instrumented couplings. A more comprehensive discussion of the computer model is presented in another recent paper [I]. The experimental work and the development of the computer model were funded by the Gas Research Institute (GRI).
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