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