Prepn. of ends of flexible metal pipes - by using inner corrugated pipe clad with braiding, to facilitate subsequent assembly by welding

Prepn. is of end of a flexible metal pipe made up of an inner corrugated pipe with parallel waves clad with a tubular braided envelope enabling it to be welded to a union. Method is by cutting the length of pipe (2) and engaging, at each of its ends, a fixed braid collar (5) destined to be connected, ultimately, by a ribbon of weld material (7,7',7'a,7'b) to a welding union. Before cutting, the briad (4) is fitted into an annular hollow (3''a) of the corrugations of the inner corrugated pipe (3) and the cutting operation is carried out in this hollow (3''a). USE/ADVANTAGE - Method prepares the ends of flexible metal tubes easing their subsequent connection to a union by welding and ensures an adequate intimate joint which is free from centring defects. This permits the use of either manual or automatic welding techniques. There is no need to repair the inner corrugated pipe following the cutting operation whilst eliminating the risk of ruffling the braid. Ce procédé est du type consistant à tronçonner la longueur désirée de tuyau (2) et à engager, sur chacune de ses extrémités, une bague d'arrêt de tresse (5) destinée à être liée, ultérieurement, par un cordon de soudure (7) au raccord à souder. Avant tronçonnage, la tresse (4) est emboutie dans un creux annulaire (3"a) des ondulations du tuyau intérieur onduleux (3), l'opération de tronçonnage étant ensuite réalisée dans ce creux (3"a).