API 5CT Q125 Pipe Calculator
API 5CT — Hydrostatic test pressure and pipe weight. Yield strength is locked to the grade value.
API 5CT Q125 has a minimum yield of 862 MPa (125 ksi) and is produced in the quench and tempered condition for sweet service ultra-deep wells. It is specified when P110 strength is insufficient for the well's extreme downhole pressure conditions.
When to use this calculator: Calculate hydrostatic test pressure and pipe weight for Q125 ultra-deep casing during preliminary design and mill test planning.
Example (API 5CT Q125)
| OD (mm) | Wall (mm) | Result |
|---|---|---|
| 177.8 | 12.65 | 69.0 MPa | 690 bar test pressure (capped at 69.0 MPa) |
Results are reference values — verify against API TR 5C3 (OCTG) or ASME B31.8 (line pipe) before use in final design.
Pipe Weight per Metre
W = 0.02466 × t × (OD − t) | API 5C3
Hydrostatic Test Pressure (API 5CT §10.12.3)
p = (2 × f × YS_min × t) / D | Rounded to nearest 0.5 MPa. Max 69.0 MPa.
f = 0.8 (standard coefficient for this grade and all sizes).
Related Resources