... , SCH40, STD, SCH80, SCH100, SCH120, SCH160Surface treatmentblack paint, varnish, rust-proof oil, and hot-dipped galvanizedApplicationChemical industry, petroleum industry, construction industry, domestic ... International Quality System.Our main products include elbows, reducers, tees, flanges, big elbows,socket pipe, concrete pumps and pipes, concrete pipeline ...