Couplings are short lengths of pipe used to connect 2 joints of tubing or casing. They come with painted color codes on their external surface to indicate their grades. Standard:API Spec 5CT and 5B Tread types: NUE, EUE, VAM, STC, LTC, BTC, special clearance, XC,VAM TOP,NEW VAM.
Oil and Gas Couplings are short lengths of pipe used to connect 2 joints of tubing or casing. They come with painted color codes on their external surface to indicate their grades.
oil casing couplings and oil tubing couplings have different thread types.
Standards and Technical Conditions for Supply:API Spec 5CT and 5B
Size: 1.9” --20”
Grade: J55,K55,N80-1,N80Q,L80-1,C90,C95,T95,P110,Q125
Thread types of couplings: NUE, EUE, VAM, STC, LTC, BTC, special clearance, XC,VAM TOP,NEW VAM.
Packing: by carton, wooden case, wooden pallet or customized
Stainless Steel Coupling
ASTM / ASME SA A182 F304, 304H, 309, 310, 316, 316L, 317L, 321, 347, 904
Carbon Steel Coupling
ASTM/ ASME A 105, ASTM/ ASME A 350 LF 2
Alloy Steel Coupling
ASTM / ASME A182 F1/ F5/ F9/ F11/ F22/ F91
Nickel Alloy Coupling
ASTM / ASME SB 336 UNS 2200 (NICKEL 200) , UNS 2201 (NICKEL 201 ) , UNS 4400 (MONEL 400 ) , UNS 8020 ( ALLOY 20 / 20 CB 3 ) , UNS 8825 INCONEL (825) , UNS 6600 (INCONEL 600 ) , UNS 6601 (INCONEL 601) , UNS 6625 (INCONEL 625) , UNS 10276 (HASTELLOY C 276)
Duplex Steel Coupling
ASTM A 182 – F 51, F53, F55 S 31803, S 32205, S 32550, S 32750, S 32760
Steel Pipe Coupling are used to connect two pipes or tubes together by screwed ( threaded) or socket welding. It comes in many shapes and sizes.
Threaded Reducing Couplings
Full Threaded Couplings
Half Threaded Couplings
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Size and Specifications For Tubing and Casing Couplings for oil and gas |
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Descriptions and size |
Type of Therad |
O.D*L |
Weight |
Descriptions and size |
Type of Therad |
O.D*L |
Weight |
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|
(mm) |
(kg) |
(mm) |
(kg) |
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|
Casing Coupling |
4-1/2″ |
STC |
127.00*158.75 |
5.23 |
Tubing Coupling |
1.05 |
NUE |
33.35*80.96 |
0.23 |
|
4-1/2″ |
LTC |
127.00*177.80 |
4.15 |
1.05 |
EUE |
42.16*82.55 |
0.38 |
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4-1/2″ |
BTC |
127.00*225.42 |
4.55 |
1.315 |
NUE |
42.16*82.55 |
0.38 |
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5″ |
STC |
141.30*165.10 |
4.66 |
1.315 |
EUE |
48.26*88.90 |
0.57 |
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5″ |
LTC |
141.30*196.85 |
5.75 |
1.66 |
NUE |
52.17*88.90 |
0.59 |
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5″ |
BTC |
141.30*231.78 |
5.85 |
1.66 |
EUE |
58.88*95.25 |
0.68 |
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5-1/2″ |
STC |
153.67*171.45 |
5.23 |
1.9 |
NUE |
55.88*95.25 |
0.56 |
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5-1/2″ |
LTC |
153.67*203.20 |
6.42 |
1.9 |
EUE |
63.50*98.42 |
0.84 |
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5-1/2″ |
BTC |
153.67*234.95 |
6.36 |
2-3/8″ |
NUE |
73.02*107.95 |
1.28 |
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6-5/8″ |
STC |
187.71*184.15 |
9.12 |
2-3/8″ |
EUE |
77.80*132.82 |
1.55 |
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6-5/8″ |
LTC |
187.71*222.25 |
11.34 |
2-7/8″ |
NUE |
88.90*130.18 |
2.34 |
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6-5/8″ |
BTC |
187.71*244.48 |
11.01 |
2-7/8″ |
EUE |
93.17*133.35 |
2.4 |
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7″ |
STC |
194.46*184.15 |
8.39 |
3-1/2″ |
NUE |
107.95*142.88 |
3.71 |
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7″ |
LTC |
194.46*228.60 |
10.83 |
3-1/2″ |
EUE |
114.30*146.05 |
4.1 |
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7″ |
BTC |
194.46*254.00 |
10.54 |
4″ |
NUE |
120.65*146.05 |
4.35 |
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7-5/8″ |
STC |
215.90*190.50 |
12.3 |
4″ |
EUE |
127.00*152.40 |
4.82 |
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7-5/8″ |
LTC |
215.90*234.95 |
15.63 |
4-1/2″ |
NUE |
132.08*155.58 |
4.89 |
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7-5/8″ |
BTC |
215.90*263.52 |
15.82 |
4-1/2″ |
EUE |
141.30*158.75 |
6.05 |
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8-5/8″ |
STC |
244.48*196.85 |
16.23 |
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8-5/8″ |
LTC |
244.48*254.00 |
21.67 |
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8-5/8″ |
BTC |
244.48*269.88 |
20.86 |
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9-5/8″ |
STC |
269.88*196.85 |
18.03 |
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9-5/8″ |
LTC |
269.88*266.70 |
25.45 |
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9-5/8″ |
BTC |
269.88*269.88 |
23.16 |
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10-3/4″ |
STC |
298.45*203.20 |
20.78 |
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10-3/4″ |
BTC |
298.45*269.88 |
25.74 |
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11-3/4′ |
STC |
323.85*203.20 |
22.64 |
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11-3/4′ |
BTC |
323.85*269.88 |
28.03 |
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13-3/8″ |
STC |
365.12*203.20 |
25.66 |
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13-3/8″ |
BTC |
365.12*269.88 |
31.77 |
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16″ |
STC |
431.80*228.6 |
34.91 |
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16″ |
BTC |
431.80*269.88 |
40.28 |
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18-5/8″ |
STC |
508.00*228.60 |
51.01 |
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18-5/8″ |
BTC |
508.00*269.88 |
62.68 |
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20″ |
STC |
533.40*228.6 |
43.42 |
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20″ |
LTC |
533.4*292.10 |
57.04 |
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20″ |
BTC |
533.40*269.88 |
50.1 |
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API 5CT – Specification for Casing and Tubing
Spec 5CT specifies the technical delivery conditions for steel pipes (casing, tubing, plain end casing liners, and pup joints) and accessories.
Applicable to the following connections in accordance
（1）short round thread casing (STC);
（2）long round thread casing (LC);
（3）buttress thread casing (BC);
（4）extreme-line casing (XC);
（5）non-upset tubing (NU);
（6）external upset tubing (EU);
（7）integral joint tubing (IJ).
This standard specifies the technical delivery conditions for steel pipes (casing, tubing, and pup joints), coupling stock, coupling material, and accessory material and establishes requirements for three Product Specification Levels (PSL-1, PSL-2, PSL-3). The requirements for PSL-1 are the basis of this standard. The requirements that define different levels of standard technical requirements for PSL-2 and PSL-3, for all grades except H-40, L-80 9Cr, and C110, are contained in Annex H. This standard can also be applied to tubulars with connections not covered by API standards,Not applicable to threading requirements.
API 5B-Specification for Threading, Gauging, and Thread Inspection of Casing, Tubing, and Line Pipe Threads
API 5B is the standard specification for threading, gauging, and inspection of Casing, Tubing and line pipe threads.
Spec 5B covers dimensions and marking requirements for API Master thread gauges. Additional product threads and thread gauges, as well as instruments and methods for the inspection of threads for line pipe, round thread casing, buttress casing, and extreme-line casing connections, are included. It is applicable when so stipulated in the API standard governing the product. The inspection procedures for measurements of taper, lead, height, and angle of thread are applicable to threads having 111/2 or less turns per in. (111/2 or less turns per 25.4 mm). All thread dimensions shown without tolerances are related to the basis for connection design and are not subject to measurement to determine acceptance or rejection of product.
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Chemical Composition(%) |
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| Grade | C | Mn | Mo | Cr | Ni | Cu | P | S | Si |
| H40 | ≤0.03 | ≤0.03 | — | ||||||
| J55/K55 | ≤0.03 | ≤0.03 | — | ||||||
| N80-1/N80Q | ≤0.03 | ≤0.03 | — | ||||||
| R95 | ≤0.45ᶜ | ≤1.9 | ≤0.03 | ≤0.03 | — | ||||
| L80 | ≤0.43ᵃ | ≤1.9 | ≤0.03 | ≤0.03 | — | ||||
| L80-1 | ≤0.15 | 0.30~0.60 | 0.90~1.10 | 8.00~10.0 | — | — | ≤0.03 | ≤0.03 | ≤0.45 |
| L80-13Cr | 0.15~0.22 | 0.25~1.00 | 12.0~14.0 | ≤0.25 | ≤0.35 | ≤0.03 | ≤0.03 | ≤0.45 | |
| C90 | ≤0.35 | ≤1.20 | 0.25ᵇ~0.85 | ≤1.50 | ≤0.5 | ≤0.25 | ≤0.02 | ≤0.01 | ≤1 |
| T95 | ≤0.35 | ≤1.20 | 0.25ᵇ~0.85 | 0.40~1.50 | ≤0.5 | ≤0.25 | ≤0.02 | ≤0.01 | ≤1 |
| C110 | ≤0.35 | ≤1.20 | 0.25~1.00 | 0.40~0.15 | ≤0.99 | — | ≤0.02 | ≤0.01 | — |
| P110 | ≤0.99 | — | ≤0.02 | ≤0.01 | — | ||||
| Q125 | ≤0.35 | 1.35 | ≤0.85 | ≤1.50 | ≤0.99 | — | ≤0.02 | ≤0.005 | — |
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Mechanical properties |
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| Grade | Total elongation under load（%） | Yield strength（Mpa） | Tensile strength（Mpa） | Hardness（HRC） | Hardness（HBW） |
| H40 | 0.5 | 276~552 | 414 | — | — |
| J55 | 0.5 | 379~552 | 517 | — | — |
| K55 | 0.5 | 379~552 | 655 | — | — |
| N80-1/N80Q | 0.5/0.5 | 552~758/552~758 | 689/689 | — | — |
| R95 | 0.5 | 655 | 724 | — | — |
| L80 | 0.5 | 552 | 655 | 23.0 | 241 |
| L80-1/L80-9Cr | 0.5 | 552 | 655 | 23.0 | 241 |
| L80-13Cr | 0.5 | 552 | 655 | 23.0 | 241 |
| C90 | 0.5 | 621 | 689 | 25.4 | 255 |
| T95 | 0.5 | 655 | 724 | 25.4 | 255 |
| C110 | 0.7 | 758 | 793 | 30.0 | 286 |
| P110 | 0.6 | 758 | 862 | — | — |
| Q125 | 0.65 | 862 | 931 | b | — |
Coupling Pipe Grade Identification By Paint Color
| Coupling colour code | |||||
| Grade | Grade Type | Colour(s) for Coupling | Number andcolour of bandsfor product | Picture | |
| EntireCoupling | Band(s) | ||||
| H40 | None | Same as for pipe | None/black band at the manufacturer’s option |  |
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| J55 Tubing | Bright Green | None | One Bright Green |  |
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| J55 Casing | Bright Green | One White | One Bright Green |  |
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| K55 | Bright Green | None | Two Bright Green |  |
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| M65 | M65Pipe uses L80Type 1Couplings | One Bright GreenOne Blue |  |
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| N80 | 1 | Red | None | One Red |  |
| N80 | Q | Red | One Green | One RedOne Bright Green |  |
| R95 | Brown | None | One Brown |  |
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| L80 | 1 | Red | One Brown | One RedOne Brown |  |
| L80 | 9Cr | None | Two Yellow | One Red,One Brown,Two Yellow |  |
| L80 | 13Cr | None | One Yellow | One Red,One Brown,One Yellow |  |
| C90 | 1 | Purple | None | One Purple |  |
| T95 | 1 | Silver | None | One Silver |  |
| C110 | White | Two Brown | One White,Two Brown |  |
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| P110 | White | None | One White |  |
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| Q125 | Orange | None | One Orange |  |
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