ppr stop  valve is PPR pipe and PPR plastic union,  are a new generation of environment-friendly construction materials developed in the 1990s.Besides plastic tubesmerits such as lightness, corrosion resistance, anti-deposition and long service life, PP-R tubes also enjoy some other advantages ,like hygienicness, heat-resistance and longer service life. Meanwhile, their coefficient of heat conductivity is quite low and they are good at heat preservation and energy conservation. Because of the technique of thermosol binding, they are convenient to be installed and reliable in joints. Also, the materials can be recycled. Therefore, they are worthy of the nameenvironment-friendly construction materials. Compared with aluminum multiunit tubes, PP-R tubes can be made into tubular products with larger calibers, with the largest reaching more than 160mms in caliber. Shengtong PP-R tubular products and pipe fittings are widely used in such areas as delivery of drinking water, production and delivery system of purified water and drinks, transportation of chemical fluids, heating pipes, circulation system of hot water, pipes in agriculture, planting in gardens and parks and ranches, etc.