⑴ The tubing coupling is a joint for connection of two items of tubing
★ Steel grade: J55, K55, N801, N80Q, L80 1, L80 9Cr, L80 13Cr, C90, T95, P110, Q125, and so on
★ Specification: 2 3/8″, 2 7/8″, 3 1/2″, 4″, 4 1/2″, etc.
★ Thread type: Long round string(LC), short round string(STC), uphold string(BC), special thread, and more.
⑵ API Non Upset Tubing Coupling
★ The dimension classification for the coupling coincides as the size designation for the pipeline on which the coupling is used.
★ Tolerance on outdoors diameter W: +_1%.
⑶ API External Upset Tubing Coupling
★ The size designation for the coupling is the same as the size classification for the pipe on which the coupling is made use of.
★ Tolerance on outdoors diameter W: +_1%.
★ Tolerance on outside diameter Wc: +_0,38 mm.