Profile: Permanent Steel Manufacturing Co.,Ltd is a supplier of quality kinds of carbon steel pipe, stainless steel products, hollow section and numerous types of piping fittings including elbow, reducer, & flanges. We offer numerous types of piping equipment including Bend, Cap, Coupling, Elbow, Reducer, Stub End, Tee, Olet, Joint, and Gaskets. We are an ISO 9001:2015 certified company. HDPE gas pipe is suitable for the gas conveying pipe system whose operating temperature range from -20 °C to -40°C and long time maximum working pressure no more than 0.7 MPA.