Threaded coupling connection for external-upset tubing pipes
Intended for use in oil and gas wells.
The peculiar design feature of connections with the thread of round (triangular) profile is that the thread fits along the lateral sides of the triangular profile. The required tightness of the connection is ensured by thread-lubricant sealing of clearances during the mechanical make-up.
The thread profile has the angle of 60°, taper of 1:16. The threading on upset ends of the pipe allows for the increase of thread tensile strength due to the increase of wall thickness in areas of stress concentration. The upset threaded part can be standard or elongated.
- In case of correct mechanical make-up, the coupling face moves up to the surface of pipe thread run-out end.
Main features of external-upset tubing pipe connections, EU as per API Spec 5 CT
|Outer diameter D, mm||Wall thickness S, mm||Inner diameter d, mm||Weight* of 1 m pipe, kg||Outer diameter Dc, mm||Coupling length Lc, mm||Weight*, kg|
|* — estimated value
** — parameters of special couplings