... , STD, SCH80, SCH100, SCH120, SCH160Surface treatmentblack paint, varnish, rust-proof oil, and hot-dipped galvanizedApplicationChemical industry, petroleum industry, construction industry, domestic installation ... products include elbows, reducers, tees, flanges, big elbows,socket pipe, concrete pumps and pipes, concrete pipeline, various groud pipes, horizontal tubes, straight ...