... long service life Pp-r pipePp-r pipe and tube type, using polypropylene is become by extrusion of polypropylene ... .21 w/mk, only for steel 1/200.3, good resistance to heat. Pp-r pipe vicat ... , reliable connect. Pp-r good weldability, pipe, tube can be used to melt and fused connection, convenient ... system PN2.0 MPa experiment.it choose pipe, tube.3 and in consideration of the above three principles, ...