Reliable Pipes And Tubes Ltd manufactures Steel Pipe Couplings. Reliable Pipes and Tubes Ltd is an ISO 9001:2008 certified company. Steel Pipe Couplings is availed with ANSI, BS [half and full standard]. The couplings are made of Niobium, Nimonics, duplex nipple, super duplex nipple. Steel Pipe Coupling offers 2000 lbs, 3000 lbs, 6000 lbs, 9000 lbs classes.