Series 700 Teflon® lined expansion joints are the Series 500 built over a preformed Teflon® tube. Since the Series 500 body provides the backing, we can withstand very high pressures and high temperatures. Teflon® lined expansion joints are used wherever the chemical content of the fluid is so corrosive as to be beyond the physical tolerance of a rubber material. They are also used in systems where conventional rubber might stand up quite well, but contamination must be avoided. We have built Series 700 joints as large as 60″ (1500mm) in diameter.