API 5CT J55 casing coupling is a standardized pipe connection component in petroleum drilling engineering. Its core function is to achieve mechanical connection between adjacent casing sections through internal thread structures, forming a complete casing string structure. In the wellbore structure, this component must withstand downhole axial loads and formation pressure to ensure the overall sealing integrity of the casing string. The specially designed double-shoulder structure and composite sealing system enhance sealing reliability in high-pressure oil/gas environments.
Specification
Type: Coupling.
Material: J55.
Standard: API 5CT.
Size: DN76, EUE.
Casing Coupling Manufacturing Process
The production of casing couplings comprises two main stages: blank preparation and precision machining.
Blank Forming:
Uses hot-rolled seamless steel pipes subjected to normalizing treatment.
Machining allowance for outer diameter: 1.5–3 mm.
Thread Machining:
CNC machines threads per API 5B standards, equipped with 3-coordinate inspection systems to ensure precision.
Surface Treatment:
Copper plating process with current density controlled at 3–5 A/dm².
Plating adhesion strength: ≥15 MPa.
Final Inspection:
100% magnetic particle testing and thread go/no-go gauge inspection.
