PE water supply pipes and PP-R pipes are connected with special steel-plastic fittings, one with internal thread and one with external thread. Thermal butt connection is not allowed, because the materials of the two are different, and the melting point is different.
PE pipes include medium-density polyethylene pipes and high-density polyethylene pipes. According to the wall thickness, it is divided into SDR11 and SDR17.6 series. The former is suitable for transporting gaseous artificial coal gas, natural gas, and liquefied petroleum gas, while the latter is mainly used for transporting natural gas. Compared with steel pipes, the construction process is simple and has a certain degree of flexibility. The more important thing is that it is not used for anti-corrosion treatment, which will save a lot of working procedures. The disadvantage is that the equipment is not as good as steel pipes. Special attention should be paid to the safety distance of thermal heating during construction, and it should not be exposed to the sun in the air, and it is sensitive to chemicals to prevent leakage of sewage pipes from causing damage.