Prodn. of double wall branched pipe - by making hole in inner PVC liner, bonding PVC sleeve to it, forming concrete shell round assembly and push=fitting cylinder into sleeve

摘要

A double-wall pipe with branch is produced from concrete outer and plastic inner pipes, in which a pipe-member surrounds a hole in the inner pipe end is bonded to it. At least one hole is made in the inner liner for the branch. A suitably orientated cylindrical pipe is bonded to the liner, its end being in line with the concrete shell which will be applied. A hard-setting concrete shell is then wrapped round this last cylinder as well as the liner and it sets hard up to the outer pipe. The bonded-on cylinder is pref. fitted with a removable holder of polystyrene foam. ADVANTAGE - The prod. is simple to make. Its transition points from the inner liner to the outer pipe remain tightly sealed. It can be readily joined up to the other pipes of various materials.