... reliable, not only for hot and cold water pipe, also can be used for pure water system.2, heat insulating and energy-saving ... .Pp-r pipe main USES what?1, building of hot and cold water systems, including centralized heat-supply system,2 the heating system ... , building, including floor, wall panels and radiant heating system,Three, can be directly drinkable water supply system,4 and the central air ...