Developments in the welding of PE 50 polyethylene pipes and in the relevant qualifications

Abstract With the introduction of the Ministerial Decree of 24 November 1984, which allows the use of polyethylene in the construction of underground pipelines for gas transportation, the said material and the relevant tvelding techniques have undergone considerable development in Italy. This paper describes the main characteristics of this unusual plastic and indicates the welding processes normally used for joining P E pipes and fittings. The accent is placed on the present possibilities of destructive and non-destructive testing of the welded joints, and an outline is given of the new Italian plan for the qualification of welders of polyethylene, prepared by UNIPLAST in conjunction with the Italian Welding Institute.