Casing coupling is a short pipe used for connecting two casing pipes which have threads. This pipe coupling has internal threads (box thread) machined to match the external threads (pin thread) of the long joints of casing. The two joints of casing pipes are screwed into opposite ends of the casing coupling. The couplings are normally made of the same grade of steel as the casing. Through their strength can be different from the casing. All casing couplings are manufactured according to API 5CT specification of the latest edition.
Properties
1. The material of this product can be H40, J55, K55, M65, N80-1, N80Q, L80, C95, T95 and P110 grade steel.
2. The outer diameter of the casing couplings ranges from 127mm to 365.12 mm (4 1/2"~13 3/8")
3. Thread patterns of the pipe couplings include short round thread (STC), long round thread (LC) and buttress thread (BC).
Size, Tolerance and Weight of API Round-Thread Casing Coupling
Parameters FormsCode 1 | Specification (a) | Outer Diameter | Min. Length (mm) | Boring Diameter | Bearing Surface Width | Weight (kg) | ||
Outer Diameter (mm) | W (mm) | Short Coupling NL | Long Coupling NL | Qb mm | b mm | Short Coupling | Long Coupling | |
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |
4-1/2 | 114.30 | 127.00 | 158.75 | 177.80 | 116.68 | 3.97 | 3.62 | 4.15 |
5 | 127.00 | 141.30 | 165.10 | 196.85 | 129.38 | 4.76 | 4.66 | 5.75 |
5-1/2 | 139.70 | 153.67 | 171.45 | 203.20 | 142.08 | 3.18 | 5.23 | 6.42 |
6-5/8 | 168.28 | 187.71 | 184.15 | 222.25 | 170.66 | 6.35 | 9.12 | 11.34 |
7 | 177.80 | 200.03 | 184.15 | 228.60 | 180.18 | 4.76 | 8.39 | 10.83 |
7-5/8 | 193.70 | 215.90 | 190.50 | 234.95 | 197.64 | 5.56 | 12.30 | 15.63 |
8-5/8 | 219.08 | 244.48 | 196.85 | 254.00 | 223.04 | 6.35 | 16.23 | 21.67 |
9-5/8 | 244.48 | 269.88 | 196.85 | 266.70 | 248.44 | 6.35 | 18.03 | 25.45 |
10-3/4 | 273.05 | 298.45 | 203.20 | - | 277.02 | 6.35 | 20.78 | - |
10-3/4 | 298.45 | 323.85 | 203.20 | - | 302.42 | 6.35 | 22.64 | - |
13-3/8 | 339.72 | 365.12 | 203.20 | - | 343.69 | 5.56 | 25.66 | - |
a: The code of the specification of the coupling is same as the relevant tube. b: For group1, 2 and 3, the outer diameter tolerance is ±1%, but not more than ±3.18 mm. c: For group 4, he outer diameter tolerance is ±1%, but not more than +3.18 -1.59 mm. d: For all groups, tolerance of boring diameter Q is +0.790 mm. |
Size, Tolerance and Weight of API Buttress Thread Casing Coupling
Code 1 | Specification (a) | Outer Diameter | Min. Length | Boring Diameter | Bearing Surface Width | Weight (kg) | ||
Outer Diameter D | Standard Coupling | Special Space Coupling (d) | ||||||
(mm) | Wb,c mm | WC mm | NL mm | Q mm | b mm | Standard Coupling | Special Space Coupling | |
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |
4-1/2 5 5-1/2 6-5/8 7 7-5/8 8-5/8 9-5/8 10-3/4 11-3/4 13-3/8 |
114.30 127.00 139.70 168.28 177.80 193.68 219.08 244.48 273.05 298.45 339.72 |
127.00 141.30 153.67 187.71 200.03 215.90 244.48 269.88 298.45 323.85 365.12 |
123.82 136.52 149.22 177.80 187.32 206.38 231.78 257.18 285.75 - - |
225.42 231.78 234.95 244.48 254.00 263.52 269.88 269.88 269.88 269.88 269.88 |
117.86 130.56 143.26 171.83 181.36 197.23 222.63 248.03 276.61 302.01 343.28 |
3.18 3.97 3.97 6.35 5.56 7.94 9.52 9.52 9.52 9.52 9.52 |
4.55 5.85 6.36 11.01 10.54 15.82 20.86 23.16 25.74 28.03 31.77 |
3.48 4.00 4.47 5.65 6.28 9.29 10.80 12.02 13.39 - - |
a: The code of the specification of the coupling is same as the relevant tube. b: For group1, 2 and 3, tolerance of the outer diameter W is ±1%, but not more than ±3.18 mm. c: For group 4, tolerance of the outer diameter W is ±1%, but not more than +3.18 mm –1.59 mm. d:For group 4, tolerance of the outer diameter Wc is +0.79 mm–0.40 mm. |