API 5CT Casing Coupling

|

 Product Description

1）A Casing Coupling is a critical threaded connector used to join sections of casing pipes in oil and gas wells, ensuring structural integrity and pressure containment across the wellbore. Manufactured to API 5CT/5B specifications, these couplings provide a leak-proof seal in high-pressure, high-temperature (HPHT) and corrosive environments. They are designed to withstand axial, tensile, and compressive loads while maintaining alignment and sealing performance throughout the well’s lifecycle.

2）Casing couplings are short lengths of pipes applied to connect two joints of casing. They are painted different color codes on their external surface to indicate their grades. Casing coupling and tubing coupling are manufactured according to API 5CT and 5B specifications.

|

 Comment & FAQ

1. What’s the difference between API Buttress and Premium threads?

A: API Buttress is a standard thread for general applications, while Premium threads offer enhanced sealing for HPHT/sour conditions.

2. Can couplings be reused after disassembly?

A: Not recommended – thread wear may compromise sealing integrity. Always use new couplings for critical wells.

3. Do you supply couplings for sour service (H₂S environments)?

A: Yes – we offer NACE MR0175-compliant materials and coatings.

4. What’s the lead time for non-API sizes?

A: Typically 4–6 weeks, depending on material and thread specifications.

5. How to verify coupling thread quality?

A: Use API-certified ring gauges and inspect for thread profile, pitch, and surface finish.

|

 

Certifications

| Grade Color Codes

Grade	Grade  Type	Number and Color of Bands for Product a with Length ≥6.0 ft	Color(s) for Couplings
			Entire Coupling	Band(s) b,c
1	2	3	4	5
H40	-	None or black band at the manufacturer’s option	None	Same as for pipe
J55 Tubing	-	One bright green	Bright green	None
J55 Casing	-	One bright green	Bright green	One white
K55	-	Two bright green	Bright green	None
N80	1	One red	Red	None
N80	Q	One red, one bright green	Red	Green
R95	-	One brown	Brown	None
L80	1	One red, one brown	Red	One brown
L80	9Cr	One red, one brown, two yellow	None	Two yellow
L80	17C	One red, one brown, one yellow	None	One yellow
C90	-	One purple	Purple	None
T95	-	One silver	Silver	None
C110	-	One white, two brown	White	Two brown
P110	-	One white	White	None
Q125	-	One orange	Orange	None
a In the case of coupling material, unless otherwise specified in the purchase agreement, the manufacturer’s internal requirements shall govern. b Special clearance couplings shall also have a black band. c Seal-ring couplings shall also have a blue band.

|

 Painting Sample