API 5CT Tubing And Casing Coupling News

As we know steel pipe coupling is a short pipe or tube that with threads on both ends, used to connect pipelines. So It is a kind of pipe fittings that with threaded connection, the advantage is easy for pipeline maintenance or to replace the broken pipe.

API Coupling refers to the steel couplings that used in connecting casing pipe and tubing. Also known by OCTG coupling, it is usually manufactured in seamless type, material grade same with the pipe body (API 5CT K55/J55, N80, L80, P110 etc), same PSL or providing higher grades than requested. Same heat treatment also applicable, except there is an special requirements.

Normally tubing coupling OD maximum is 4 1/2”, mostly used is thicken type upset coupling (Internal upset and external upset), for short is EUE coupling,  Buttress coupling another type used for tubing connections, it has the same thickness of the pipe body, called NU end (NUE)tubing .

Casing coupling is for the dimensions more than 4 1/2 inch. Differently than tubing coupling is, casing coupling normally does not need to be thickened (Non-upset), which means no upset casing coupling, so it has following types:

Round thread  • LTC/LC: Long round thread casing coupling

            • STC/SC: Short round thread casing coupling

Buttress thread • BTC/BC: Buttress thread casing coupling

All three types has same thickness of the casing pipe body, just have different lengths.