steel pipe standards ASTM, API, DIN, EN, BS, JIS, UL, ISO used in structure, liquid transfering, sprinkler syetem.frame Steel pipeincluding ERW and ... tube, structural tube, scaffolding tube, water transferring tube, oil pipe, casing pipe, sprinkler fire fighting system tube (with groove or not), EMT ... , furniture tube and so onCERTIFICATE: ISO9001, UL, FM, CE steel pipe