ERW STEEL PIPE Standard: GB/T 13793, YB/T5209, GB9947 Steel Grade: Q195,Q235,SPHC,SPHT2,SS400 OD: ... .6-3.5MM ERW STEEL PIPE1) Standard: GB/T 13793, YB/T5209, GB99472) Steel Grade: Q195,Q235,SPHC,SPHT2,SS4003) Outside ... pipes.QUALITY ASSURANCE:1) Strictly acc. To GB/T 13793, YB/T5209, GB99472) Widely for HRSG, Boiler; Heat Exchanger, Condensor; Pipeline ...