Continuous 40-ft. Pipes

 Pipes in 40-ft sections are especially useful for transfer lines and other long, straight runs. They come in swaged polytetrafluoroethylene- (PTFE), polypropylene- (PP) and polyvinylidene fluoride- (PVDF) lined pipe in 1.5- to 6-in. sizes, and in perfluoroalkoxy- (PFA)lined pipe in 1.5- to 2-in. sizes. Plastic-lined pipe that is loose-lined or reverse-swaged — where the liner is compressed then inserted into a steel shell, where it expands —has  been limited in length to 20 ft. Longer sections are fabricated by compressing the steel shell down on the liner during the picking and swaging process. This locks the liner in place to inhibit differential movement during temperature cycling.