... HDPE double-wall corrugated pipe of all types, HDPE (fro pp-R pipe fittings 90° elbowThe company is mainly engaged in researching ... type DN20 to type DN1200) water supply, gas supply pipe, PP-R (from type DN20 to type DN160) cold & hot pipe, PE ... annual sales of pipes and pipe fittings 50,000 tons. PP-R pipe fittings