中文版 (Chinese): README_cn.md
API NU stands for Non-Upset: API round-thread tubing with plain (non-upset) pipe ends and a standard coupling, manufactured to API 5CT (product specification) and API 5B (thread gauging).
This repository publishes NU tubing connection data sheets. For every size (OD × wall × grade) combination there are two mirrored editions:
| Edition | Language | Unit system | Directory |
|---|---|---|---|
| CN / SI | 中文 (Chinese) | SI — mm, MPa, kN, kg/m | NU_SI_CN/ |
| EN / USC | English | US Customary — in, psi, lbf, lb/ft | NU_USC_EN/ |
Both editions carry identical engineering content; only the language and units differ.
16 OD × wall-thickness combinations, 238 datasheets per unit system.
| Nominal OD (mm / in) | Wall thickness (mm) |
|---|---|
| 26.67 / 1.050 | 2.87 |
| 33.40 / 1.315 | 3.38 |
| 42.16 / 1.660 | 3.56 |
| 48.26 / 1.900 | 3.68 |
| 60.32 / 2.375 | 4.24, 4.83, 6.45 |
| 73.02 / 2.875 | 5.51, 7.01, 7.82 |
| 88.90 / 3.500 | 5.49, 6.45, 7.34, 9.52 |
| 101.60 / 4.000 | 5.74 |
| 114.30 / 4.500 | 6.88 |
Grades
- API standard grades: H40, J55, L80-1, N80-1, N80-Q, C90, R95, T95, P110, Q125
- Sour-service grades (BG series): BG80S, BG80SS, BG90S, BG90SS, BG95S, BG95SS, BG110S, BG110SS, BG125S
S= sour service (H₂S-resistant),SS= super-sour service.
These datasheets are provided for engineering reference only. Performance values are calculated at the 87.5 % minimum wall condition per API standards. For project-specific requirements and the latest values, please consult Baosteel.
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