... , 180° returns, straight, reducing tees, caps, concentric and eccentric reducersRadius Of Curvature1D-10D ANSI,ASME,API5L,DIN,JIS,BS,GBSurface treatmentblack ... paint, varnish, rust-proof oil, and hot-dipped galvanizedRange Of ApplicationChemical industry, petroleum industry, construction industry, domestic installation and otherCertificatesISO ...