Plastic lined pipe mfr. - by inflation and axially moved heating and cooling to apply plastic tube on adhesive lined walls

摘要

A metal pipe is internally lined by a thin thermoplastic tube of originally smaller outside dia. than the inside dia. of the pipe. An adhesive is applied to this inside dia. and the inside of the tube is inflated. A heating device is moved along the pipe to soften the tube which is pressed by the air pressure against the pipe walls, and to activate the adhesive. This is immediately followed by a cooling device which is moved in the same axial direction. This prevents any decomposition, shrinkage or structural change in the lining material texture. The quick setting of the adhesive raises the productivity.