API coupling

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What is API Coupling?

API coupling

API coupling is short pieces of casing and tubing as a kind of connection between the individual joints. Generally speaking, API couplings are made of the same steel grade as the casing or tubing. In addition, a large number of customers demand the color coating on the couplings before shipment, because they can easily differ from the pipes after the discharge in the port.

There are different steel grades for couplings, which are identified by various colors like:
J55 / K55-Bright Green
P110-White
N80 / L80-Red

More Informations as following:

API Casing Couplings Short Thread Specifications:

Casing Size OD (inches)	Coupling Size OD (inches)	Length (inches)	Weight per Coupling (lbs)	Palletized Carton Quantity	Palletized Carton Weight
4-1/2	5.000	6.250	8.05	343	2716
5	5.563	6.500	10.18	210	2168
5-1/2	6.050	6.750	11.44	216	2501
6-5/8	7.390	7.250	19.97	115	2322
7	7.656	7.250	18.34	120	2231
7-5/8	8.500	7.500	26.93	80	2322
8-5/8	9.625	7.750	35.58	60	2132
9-5/8	10.625	7.750	39.51	50	2006
10-3/4	11.750	8.000	49.61	45	2079
11-3/4	12.750	8.000	50.49	35	1767
13-3/8	14.375	8.000	56.23	25	1436
16	17.000	9.000	78.98	20	-
18-5/8	20	9.000	118.94	10	-
20	21.000	9.000	98.25	10	-

API Casing Couplings Long Thread Specifications:

Casing Size OD (inches)	Coupling Size OD (inches)	Length (inches)	Weight per Coupling (lbs)	Palletized Carton Quantity	Palletized Carton Weight
4-1/2	5.000	7.000	9.07	294	2697
5	5.563	7.750	12.56	210	2573
5-1/2	6.050	8.000	14.03	180	2555
6-5/8	7.390	8.750	24.82	100	2315
7	7.656	9.000	23.67	100	2351
7-5/8	8.500	9.250	34.23	80	2807
8-5/8	9.625	10.000	47.48	48	2337
9-5/8	10.625	10.500	55.77	40	2302
10-3/4	11.750	* 10.500	* 62.38	45	* 36
11-3/4	12.750	* 10.500	* 67.59	30	* 24
13-3/8	14.375	* 10.500	* 76.63	25	* 20
16	17.000	* 11.000	* 96.55	20	* 16
18-5/8	20.000	-	-	10	8
20	21.000	* 11.500	* 126.74	10	8
* NOT API SPECIFICATIONS.

API Casing Coupling - Buttress Thread

Casing Size OD (inches)	Coupling Size OD(inches)	Length (inches)	Weight per Coupling (lbs)	Palletized Carton Quantity	Palletized Carton Weight
4-1/2	5.000	8.875	10.11	196	2007
5	5.563	9.125	12.99	144	2840
5-1/2	6.050	9.250	14.14	144	2061
6-5/8	7.390	9.625	24.46	92	2295
7	7.656	10.000	23.22	80	2068
7-5/8	8.500	10.375	64.84	64	2221
8-5/8	9.625	10.625	45.94	48	2414
9-5/8	10.625	10.625	50.99	40	2256
10-3/4	11.750	10.625	56.68	36	2307
11-3/4	12.750	10.625	61.74	24	2179
13-3/8	14.375	10.625	69.95	20	1429
16	17.000	10.625	87.56	16	-
18-5/8	20.000	10.625	138.03	8	-
20	21.000	10.625	110.33	8	-

API Tubing Couplings - External Upset End (EUE):

Casing Size OD (inches)	Coupling Size OD (inches)	Threads per inch	Length (inches)	Weight per Coupling (lbs)	Palletized Carton Quantity	Palletized Carton Weight
1.90	2.500	10 Round	-	1.85	-	-
2-3/8	3.063	8 Round	4.875	3.42	1,444	3942
2-7/8	3.668	8 Round	5.500	5.29	792	4220
3-1/2	4.500	8 Round	5.750	9.02	448	3860
4	5.000	8 Round	-	10.62	392	-
4-1/2	5.563	8 Round	6.500	13.31	252	3456

API Tubing Couplings - Non Upset End (NUE)

Casing Size OD (inches)	Coupling Size OD (inches)	Threads per inch	Length (inches)	Weight per Coupling (lbs)	Palletized Carton Quantity	Palletized Carton Weight
1.90	2.200	10 Round	3.750	1.85	-	-
2-3/8	2.875	10 Round	4.500	2.82	1,512	4264
2-7/8	3.500	10 Round	5.500	5.15	800	4120
3-1/2	4.250	10 Round	5.625	8.17	502	4101
4	4.75	8 Round	5.75	9.57	392	-
4-1/2	5.200	8 Round	6.500	10.76	252	2712

Coupling Pipe Grade Identification By Paint Color

Grade	Colour Coding (Painted Outside)
H-40	Black
J-55 or K-55	Green
N-80	Red
M-65 or L-80	Red with one Brown Band
L-80 Type 9CR	Red with two Yellow Bands
L-80 Type 13CR	Red with one Yellow Band
C-90 Type 1	Purple
C-90 Type 2	Purple with one Yellow Band
T-95 Type 1	Silver
T-95 Type 2	Silver with one Yellow Band
C-95	Brown
P-110	White
Q-125 Type 1	Orange
Q-125 Type 2	Orange with one Yellow Band
Q-125 Type 3	Orange with one Green Band
Q-125 Type 4	Orange with one Brown Band

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