PPR pipe fittings, also known as three-polypropylene pipe fittings, are made of random copolymer polypropylene through extrusion into pipes and injection into pipe fittings. It is a new type of plastic pipe product developed and applied in Europe in the early 1990s. PPR is a new generation of pipe materials, which has been randomly and uniformly polymerized (random copolymerization) with about 5% PE in the PP molecular chain through a gas-phase copolymerization process in the late 1980s. It has good impact resistance and long-term creep properties.