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 isan special requirements.
Features:
The oil tubing coupling can solve the problem of fatigue fracture in the existing coupling due to stress concentration. Oil tubing end is connected to the inside wall of the coupling in a tapered thread. The coupling body end and oil tubing are connected with same thread pitch flat thread. The coupling is not easy to produce fatigue fracture, and has good connection effect. It can prevent the accident of oil well pipe string break effectively.
| Tubing Pipe Outside Diameter (in) | Tubing Pipe Outside Diameter (mm) | Coupling Outside Diameter (mm) | Minimun Length(mm) | Diameter Of Recess(mm) | Width of Bearing Face Regular (mm) | Max Bearing Face Diameter (mm) | Mass(Kg) | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| NUE | EUE | NUE | EUE | NUE | EUE | NUE | EUE | NUE | NUE | NUE | EUE | |||||
| Regular | Special Clearance | Regular with special bevel | Special Clearance | Regular | Special Clearance | |||||||||||
| 1.9 | 48.26 | 55.88 | 63.50 | — | 95.25 | 98.42 | 49.86 | 54.76 | 1.59 | 3.18 | 52.07 | 58.34 | — | 0.56 | 0.84 | — |
| 2 3/8 | 60.32 | 73.2 | 77.80 | 73.91 | 107.95 | 123.42 | 61.93 | 67.46 | 4.76 | 3.97 | 66.68 | 71.83 | 69.90 | 1.28 | 1.55 | 1.07 |
| 2 7/8 | 73.02 | 88.90 | 93.17 | 87.88 | 130.18 | 133.35 | 74.63 | 80.16 | 4.76 | 5.56 | 80.98 | 85.88 | 83.24 | 2.34 | 2.40 | 1.55 |
| 3 1/2 | 88.90 | 107.95 | 114.30 | 106.17 | 142.88 | 146.05 | 90.50 | 96.85 | 4.76 | 6.35 | 98.42 | 104.78 | 100.71 | 3.71 | 4.10 | 2.38 |
| 4 | 101.60 | 120.65 | 127.00 | — | 146.05 | 152.40 | 103.20 | 109.55 | 4.76 | 6.35 | 111.12 | 117.48 | — | 4.35 | 4.82 | — |
| 4 1/2 | 114.30 | 132.08 | 141.30 | — | 155.58 | 158.75 | 115.90 | 122.25 | 4.76 | 6.35 | 123.19 | 130.96 | — | 4.89 | 6.05 | — |
