... structure, liquid transfering, conduit, sprinkler system.fence steel tube, including ERW and Seamless, round and rectangular or square ... , aew according to standards ASTM A53, ASTM A106, ASTM A795, ASTM A135, ASTM A500, API 5L, ... Wall thickness:0.8mm---20mm. PURPOSE: fence tube, structural tube, scaffolding tube, water transferring tube, oil pipe, casing pipe, sprinkler fire fighting ...