... Hot-melt Butt-fusion, socket-fusion & electric-fusion pipe fittings. In the 1940's, once introduced, PE pipes for ... has good flexibility, non-absorbent, avirulent insipidity, excellent electrical insulation and under normal temperl tempera temperature good acid, ... quality, gas density for steel 1/8, easy handling, flexible, simple, welding, need not roadway anticorrosive processing, construction ...