OCTG Couplings for Casing and Tubing Strings

Description

Goldenman manufactures API 5CT Casing Couplings and Tubing Couplings for connecting threaded OCTG joints in drilling, completion, production, injection and workover operations.

The complete product range includes:

• Tubing Couplings from 1.900 to 4-1/2 in
• Casing Couplings from 4-1/2 to 20 in
• NUE Non-Upset Tubing Couplings
• EUE External-Upset Tubing Couplings
• STC Short Round-Thread Casing Couplings
• LTC Long Round-Thread Casing Couplings
• BTC Buttress-Thread Casing Couplings
• Regular Couplings
• Special-Clearance Couplings
• Special-Bevel Couplings
• Coupling Blanks and Coupling Stock
• Standard-service and sour-service grades
• Carbon-steel, low-alloy-steel and corrosion-resistant-alloy materials
• Standard API connections and customer-specified premium connections

Each coupling is manufactured according to the tubular outside diameter, nominal weight, wall thickness, steel grade, connection type, thread profile, coupling OD, coupling length and well-service environment.

Product Short Description

Goldenman API 5CT Casing and Tubing Couplings are seamless, internally threaded OCTG connectors used to join two pin-ended tubular joints.

Tubing Couplings are supplied with NUE or EUE internal threads for production tubing, injection tubing and workover strings.

Casing Couplings are supplied with STC, LTC or BTC threads for surface casing, intermediate casing, production casing and liner strings.

Coupling material, heat treatment and mechanical properties are matched to the specified tubular grade. Finished couplings undergo dimensional inspection, thread gauging, hardness testing, surface inspection and nondestructive examination before protective coating and packaging.

Product Highlights

• Manufactured to API Spec 5CT requirements
• API Spec 5B thread dimensions and gauging
• Tubing sizes from 1.900 to 4-1/2 in
• Casing sizes from 4-1/2 to 20 in
• NUE and EUE Tubing Couplings
• STC, LTC and BTC Casing Couplings
• Regular, Special Clearance and Special Bevel types
• Seamless coupling construction
• Carbon-steel and alloy-steel materials
• J55, K55, N80, L80, P110 and Q125 configurations
• C90, T95, C110 and C125 high-performance grades
• L80 Type 1, 3Cr, 9Cr and 13Cr options
• Standard, CO₂-resistant and sour-service packages
• Full-length controlled heat treatment
• Precision-machined internal threads
• Controlled coupling bore and outside diameter
• Phosphated and coated surfaces
• Thread compound and rigid thread protectors
• Magnetic-particle and ultrasonic inspection
• Thread-gauge inspection
• Full heat and batch traceability
• Coupling blanks and finished couplings
• Complete casing and tubing string supply

General Technical Specifications

Parameter	Tubing Coupling	Casing Coupling
Product standard	API Spec 5CT	API Spec 5CT
Thread standard	API Spec 5B	API Spec 5B
Nominal pipe size	1.900–4-1/2 in	4-1/2–20 in
Standard connections	NUE and EUE	STC, LTC and BTC
Construction	Seamless internally threaded coupling	Seamless internally threaded coupling
Coupling types	Regular, Special Clearance and Special Bevel	Regular and Special Clearance
Steel grades	J55–Q125	H40–Q125
Material families	Carbon steel, low-alloy steel and CRA	Carbon steel, low-alloy steel and CRA
Heat treatment	Normalized or quenched and tempered	Normalized or quenched and tempered
Thread finish	Precision machined and gauged	Precision machined and gauged
Surface treatment	Phosphate, coating or metallic plating	Phosphate, coating or metallic plating
Inspection	Dimensions, thread gauges, hardness and NDE	Dimensions, thread gauges, hardness and NDE
Marking	Size, grade, thread, heat and batch	Size, grade, thread, heat and batch
Packaging	Individual protection in crates or pallets	Individual protection in crates or pallets

Tubing Coupling Size Range

Goldenman supplies NUE and EUE Tubing Couplings in the following standard sizes:

• 1.900 in
• 2-3/8 in
• 2-7/8 in
• 3-1/2 in
• 4 in
• 4-1/2 in

Tubing Coupling Dimensions

Tubing OD	Tubing OD	NUE Coupling OD	EUE Coupling OD	NUE Minimum Length	EUE Minimum Length
1.900 in	48.26 mm	55.88 mm	63.50 mm	95.25 mm	98.42 mm
2-3/8 in	60.32 mm	73.02 mm	77.80 mm	107.95 mm	123.82 mm
2-7/8 in	73.02 mm	88.90 mm	93.17 mm	130.18 mm	133.35 mm
3-1/2 in	88.90 mm	107.95 mm	114.30 mm	142.88 mm	146.05 mm
4 in	101.60 mm	120.65 mm	127.00 mm	146.05 mm	152.40 mm
4-1/2 in	114.30 mm	132.08 mm	141.30 mm	155.58 mm	158.75 mm

Coupling bore, bearing-face diameter, recess diameter, bevel and weight are manufactured according to the selected NUE or EUE configuration.

Casing Coupling Size Range

Goldenman supplies Casing Couplings in the following nominal sizes:

• 4-1/2 in
• 5 in
• 5-1/2 in
• 6-5/8 in
• 7 in
• 7-5/8 in
• 8-5/8 in
• 9-5/8 in
• 10-3/4 in
• 11-3/4 in
• 13-3/8 in
• 16 in
• 18-5/8 in
• 20 in

Casing Coupling Connection Matrix

Casing Size	STC	LTC	BTC
4-1/2 in	✓	✓	✓
5 in	✓	✓	✓
5-1/2 in	✓	✓	✓
6-5/8 in	✓	✓	✓
7 in	✓	✓	✓
7-5/8 in	✓	✓	✓
8-5/8 in	✓	✓	✓
9-5/8 in	✓	✓	✓
10-3/4 in	✓	✓	✓
11-3/4 in	✓	✓	✓
13-3/8 in	✓	✓	✓
16 in	✓	✓	✓
18-5/8 in	✓	✓	✓
20 in	✓	✓	✓

The finished coupling dimensions are selected from the casing OD, nominal weight, wall thickness, connection type and specified clearance requirement.

NUE Tubing Coupling

NUE means Non-Upset End.

A NUE Tubing Coupling connects tubing whose threaded ends retain the same basic outside diameter as the pipe body.

The connection consists of:

• Two externally threaded tubing pins
• One internally threaded NUE coupling
• Tapered API round threads
• Coupling bearing faces
• Pin-to-coupling thread engagement
• Thread compound sealing and lubrication

NUE Couplings have a smaller outside diameter than matching EUE Couplings.

This provides:

• Increased annular clearance
• Easier running through restricted casing
• Lower coupling weight
• Reduced external contact area
• Compatibility with non-upset tubing ends

NUE is used in:

• Conventional production tubing
• Injection tubing
• Slim-clearance completions
• Workover strings
• Low- and medium-load tubing strings

EUE Tubing Coupling

EUE means External-Upset End.

The tubing end is externally upset before threading, creating a larger and thicker connection section.

The EUE connection uses:

• Externally upset tubing pin ends
• Larger coupling outside diameter
• Increased connection cross-sectional area
• Longer thread engagement
• Larger bearing faces
• Improved tensile and connection capacity

EUE Couplings provide:

• Increased tensile efficiency
• Increased thread engagement
• Improved resistance to cyclic loading
• Stronger tubing-end connection
• Improved performance in deeper wells
• Increased resistance to handling damage

EUE is commonly used in:

• Production tubing
• Deep wells
• High-tension tubing strings
• Gas wells
• Injection wells
• Workover operations
• Wells with repeated pulling and running cycles

NUE vs EUE Tubing Couplings

Feature	NUE Coupling	EUE Coupling
Pipe end	Non-upset	External upset
Coupling OD	Smaller	Larger
Connection length	Shorter	Longer
Tensile capacity	Standard	Increased
Annular clearance	Greater	Reduced
Connection mass	Lower	Higher
Typical application	Standard and restricted-clearance tubing	High-load and deep-well tubing
Direct interchangeability	NUE pins only	EUE pins only

NUE and EUE Couplings are not interchangeable because the pin geometry, coupling bore, thread position, OD and length differ.

STC Casing Coupling

STC means Short Thread Casing.

STC uses a short round-thread connection with a relatively compact thread engagement length.

It provides:

• Fast makeup
• Standard connection dimensions
• Reduced coupling length
• Economical casing-string assembly
• Compatibility with conventional casing-handling equipment

STC is used in:

• Surface casing
• Shallow casing strings
• Moderate-load wells
• Low-deviation wells
• Conventional cemented casing strings

The short thread length gives STC lower tensile and bending capacity than comparable LTC and BTC connections.

LTC Casing Coupling

LTC means Long Thread Casing.

LTC uses the same round-thread principle as STC with increased thread engagement.

The longer connection provides:

• Increased tensile capacity
• Increased connection efficiency
• Improved resistance to bending
• Increased thread contact area
• Improved performance in deeper casing strings
• Better resistance to handling and running loads

LTC is used in:

• Intermediate casing
• Production casing
• Deeper wells
• Moderate-deviation wells
• Casing strings with higher tensile load

BTC Casing Coupling

BTC means Buttress Thread Casing.

BTC uses a trapezoidal buttress thread form designed to transmit high axial load through the connection.

BTC provides:

• High tensile efficiency
• Strong axial-load transfer
• High connection strength
• Improved resistance to thread jump-out
• Effective makeup indication
• Suitability for heavy casing strings

BTC is used in:

• Deep wells
• High-load casing strings
• Production casing
• Intermediate casing
• Horizontal and directional wells
• High-pressure and high-temperature wells
• Heavy-wall and high-grade casing

STC vs LTC vs BTC

Feature	STC	LTC	BTC
Thread form	Round thread	Round thread	Buttress thread
Engagement length	Short	Long	Connection-specific
Tensile capacity	Standard	Higher than STC	Highest of the three standard types
Makeup speed	Fast	Moderate	Moderate
Casing-string load	Low to moderate	Moderate to high	High
Typical depth	Shallow to medium	Medium to deep	Deep and high-load
Typical well profile	Vertical and low deviation	Vertical and directional	Directional, horizontal and deep
Coupling type	Internally threaded	Internally threaded	Internally threaded

Regular Couplings

Regular Couplings use the standard API outside diameter, length, bearing face and bevel configuration for the selected connection.

They provide:

• Standard pipe-string compatibility
• Full connection capacity
• Standard handling-tool compatibility
• Standard thread-protector compatibility
• Simplified inventory management

Regular Couplings are the primary configuration for conventional casing and tubing strings.

Special-Clearance Couplings

Special-Clearance Couplings use a reduced outside diameter while maintaining the specified internal connection geometry.

They are used where:

• Annular clearance is limited
• Casing must pass through a restricted wellbore
• Tubing must run inside small-diameter casing
• Existing casing deformation reduces clearance
• Downhole tools require increased annular space
• Cementing clearance must be protected

Special-Clearance Couplings are manufactured with controlled wall thickness, material grade and outside diameter.

Special-Bevel Couplings

Special-Bevel Couplings use a modified external bearing-face or end-bevel profile.

The bevel provides:

• Improved clearance during running
• Reduced snagging on ledges
• Improved passage through restrictions
• Reduced external sharp edges
• Better handling through deviated sections

Special-bevel geometry is supplied for the specified casing or tubing running program.

Coupling Blanks and Coupling Stock

Goldenman supplies:

• Hot-finished seamless Coupling Stock
• Heat-treated Coupling Stock
• Rough-machined Coupling Blanks
• Bored Coupling Blanks
• Finished unthreaded Coupling Blanks
• Fully threaded Couplings
• Premium-connection Coupling Blanks

Coupling Stock is supplied with:

• Specified outside diameter
• Specified wall thickness
• Steel grade
• Heat treatment
• Mechanical properties
• Straightness
• NDE
• Material traceability

Coupling Blanks are supplied with machining allowance for the final bore, thread and outside-diameter finish.

Steel Grade Range

Goldenman manufactures Casing and Tubing Couplings in the following API 5CT material grades:

• H40
• J55
• K55
• M65
• N80 Type 1
• N80 Type Q
• L80 Type 1
• L80 3Cr
• L80 9Cr
• L80 13Cr
• R95
• C90
• T95
• C110
• C125
• P110
• Q125

Couplings for proprietary or premium tubular grades are manufactured from customer-specified coupling stock and connection drawings.

H40, J55 and K55 Couplings

H40, J55 and K55 are used for conventional low- and medium-strength casing and tubing strings.

They are used in:

• Shallow wells
• Surface casing
• Water wells
• Conventional oil wells
• Moderate-pressure service
• Non-corrosive environments

J55 and K55 have the same minimum yield-strength level with different tensile and heat-treatment characteristics.

N80 Couplings

N80 Couplings are supplied as:

• N80 Type 1
• N80 Type Q

N80 is used in:

• Intermediate casing
• Production casing
• Production tubing
• Medium-depth wells
• Medium- and high-load tubular strings

N80 Type Q uses quenched-and-tempered heat treatment for controlled strength and toughness.

L80 Couplings

L80 Couplings include:

• L80 Type 1
• L80 3Cr
• L80 9Cr
• L80 13Cr

L80 Type 1 provides controlled strength and hardness for many sour-service and corrosion-controlled applications.

Chromium-bearing L80 materials provide increased resistance to CO₂-containing production environments.

L80 Couplings are used in:

• Sour-service wells
• CO₂-containing production
• Production tubing
• Injection tubing
• Completion strings
• Corrosion-controlled casing strings

C90 and T95 Couplings

C90 and T95 provide controlled mechanical properties and hardness for demanding sour-service applications.

They are used in:

• H₂S-containing wells
• Deep sour-gas wells
• High-pressure production
• High-tension tubing strings
• Sour-service casing strings

The complete material package includes chemical composition control, heat treatment, hardness testing and traceability.

C110 and C125 Couplings

C110 and C125 are high-strength controlled-material grades for severe well conditions.

Applications include:

• Deep sour-service wells
• High-pressure gas wells
• High axial load
• High burst and collapse requirements
• Severe completion environments

Couplings are matched to the specified pipe grade, hardness range and sour-service design.

P110 Couplings

P110 provides high yield strength for deep and highly loaded wells.

It is used in:

• Deep production casing
• High-pressure casing strings
• High-tension tubing
• Horizontal wells
• Hydraulic-fracturing wells
• High-load completion strings

P110 Couplings use quenched-and-tempered alloy steel with controlled mechanical properties.

Q125 Couplings

Q125 is used in high-strength casing strings requiring increased burst, collapse and tensile performance.

Applications include:

• Ultra-deep wells
• High-pressure wells
• Heavy casing strings
• HPHT wells
• Complex directional wells
• High-load intermediate and production casing

Q125 Coupling Blanks and finished Couplings undergo full material traceability, controlled heat treatment and enhanced inspection.

Coupling Material Selection

The coupling material package is selected from:

• Pipe grade
• Pipe nominal weight
• Wall thickness
• Connection type
• Maximum axial load
• Internal pressure
• External pressure
• Bending load
• Operating temperature
• H₂S concentration
• CO₂ concentration
• Chloride content
• Completion-fluid chemistry
• Corrosion-inhibitor program

The coupling grade and heat-treatment condition are matched to the tubular string and connection-performance requirements.

Sour-Service Couplings

Goldenman Sour-Service Couplings are manufactured for H₂S-containing production and injection environments.

The sour-service package includes:

• Controlled chemical composition
• Controlled hardness
• Quenched-and-tempered heat treatment
• H₂S-compatible material grades
• Full heat and lot traceability
• Hardness mapping
• Mechanical-property testing
• Magnetic-particle inspection
• Thread inspection
• Corrosion-protective surface treatment

Sour-service grades include L80 Type 1, C90, T95, C110, C125 and project-specific corrosion-resistant materials.

CO₂-Resistant Couplings

Chromium-bearing coupling materials are used in wells containing carbon dioxide and produced water.

Available materials include:

• L80 3Cr
• L80 9Cr
• L80 13Cr
• Stainless-steel and CRA coupling stock
• Project-specific corrosion-resistant alloys

CO₂-resistant Couplings are used in:

• Gas wells
• Water-producing oil wells
• Injection wells
• Offshore production wells
• Corrosive completion environments

Heat Treatment

Coupling heat-treatment routes include:

• Normalizing
• Normalizing and tempering
• Quenching and tempering
• Solution treatment
• Grade-specific controlled cooling

Heat treatment controls:

• Yield strength
• Tensile strength
• Hardness
• Toughness
• Ductility
• Microstructure
• Sour-service performance
• Machining stability

Coupling blanks are heat treated before final thread machining.

Seamless Coupling Construction

Goldenman Couplings are manufactured from seamless tubular coupling stock.

Seamless construction provides:

• Uniform circumferential strength
• No longitudinal weld seam
• Consistent thread machining
• Uniform heat-treatment response
• Stable mechanical properties
• Improved resistance to cyclic loading
• Reliable pressure containment

The bore and outside diameter are machined concentrically before the internal threads are produced.

Thread Manufacturing

The coupling manufacturing process includes:

1. Coupling-stock verification
2. Cutting to blank length
3. Heat treatment
4. Outside-diameter machining
5. Internal-bore machining
6. Bearing-face machining
7. Internal thread cutting
8. Thread-relief machining
9. Bevel machining
10. Thread gauging
11. Surface inspection
12. Phosphating or coating
13. Thread-compound application
14. Thread-protector installation
15. Marking and packaging

API Thread Inspection

Thread inspection covers:

• Thread form
• Pitch diameter
• Taper
• Lead
• Thread height
• Crest and root profile
• Thread length
• Vanish point
• Bearing-face position
• Coupling bore
• Thread concentricity
• Surface finish

Inspection tools include:

• Working plug gauges
• Reference master gauges
• Taper gauges
• Lead gauges
• Thread-height gauges
• Optical inspection equipment
• Coordinate-measuring equipment

Thread Compound

Thread compound provides:

• Lubrication during makeup
• Reduced galling
• Stable makeup position
• Protection against thread damage
• Improved pressure sealing
• Corrosion protection during installation

The compound is selected for:

• Standard oilfield service
• Sour service
• High temperature
• Low temperature
• Metal-free environmental requirements
• Premium connection requirements

Surface Treatment

Available coupling surface treatments include:

• Full phosphating
• Internal phosphating
• Manganese-phosphate coating
• Zinc plating
• Copper plating
• Black-oxide coating
• External protective paint
• Corrosion-resistant storage coating
• Project-specific premium-connection coating

Phosphating reduces thread friction and improves resistance to galling during makeup.

External coatings protect the coupling during transportation and storage.

Thread Protectors

Each finished coupling is supplied with rigid thread protection.

Available protectors include:

• Plastic thread protectors
• Composite protectors
• Metal protectors
• Driftable protectors
• Closed-end storage protectors

Protectors prevent:

• Thread impact damage
• Dirt contamination
• Moisture entry
• Coating damage
• Handling damage
• Foreign material entering the coupling bore

Product Identification

Each coupling is permanently marked with:

• Goldenman identification
• API 5CT product designation
• Nominal pipe size
• Connection type
• Steel grade
• Heat number
• Lot number
• Manufacturing date
• Special-clearance designation
• Sour-service designation
• Premium-connection identification where applicable

Color bands and stenciling provide additional grade identification.

Coupling Compatibility

A replacement coupling is selected using the complete tubular designation.

Required compatibility fields include:

• Tubular OD
• Nominal weight
• Wall thickness
• Steel grade
• End finish
• NUE, EUE, STC, LTC or BTC connection
• Regular or Special Clearance OD
• Thread version
• Material and heat-treatment condition

Two couplings with the same nominal pipe size are not automatically interchangeable.

A 2-7/8-inch NUE Coupling does not fit a 2-7/8-inch EUE pin.

An STC Casing Coupling does not fit LTC or BTC casing pins.

Applications

Goldenman Casing and Tubing Couplings are used in:

• Surface casing strings
• Intermediate casing strings
• Production casing strings
• Casing liners
• Production tubing strings
• Injection tubing
• Gas-lift tubing
• Workover tubing
• Water-disposal wells
• Water-injection wells
• Oil-production wells
• Gas-production wells
• Geothermal wells
• Artificial-lift completions
• Hydraulic-fracturing completions
• Offshore wells
• Onshore wells

Coupling Installation

Installation procedure:

1. Verify the coupling size, grade and thread type.
2. Inspect both pipe pins.
3. Inspect the coupling internal threads.
4. Remove storage compound and contamination.
5. Apply the specified thread compound.
6. Start the coupling squarely on the pipe pin.
7. Rotate the coupling without cross-threading.
8. Use calibrated power tongs or casing tongs.
9. Apply the specified makeup torque or position.
10. Record the final makeup.
11. Inspect for shoulder, position or triangle alignment.
12. Protect the remaining coupling end before running.

The coupling is not used to pull misaligned tubular joints into position.

Common Coupling Failure Modes

Thread Galling

Galling results from:

• Insufficient thread compound
• Damaged phosphate coating
• Contaminated threads
• Excessive makeup speed
• Misalignment
• Incorrect coupling material
• Repeated uncontrolled makeup

Connection Leakage

Leakage results from:

• Incorrect thread type
• Thread damage
• Incomplete makeup
• Excessive makeup
• Incorrect thread compound
• Corrosion
• Poor thread geometry
• Mismatched pipe and coupling grade

Coupling Cracking

Cracking results from:

• Excessive tensile load
• High bending stress
• Incorrect heat treatment
• Excessive hardness
• Sour-service cracking
• Stress concentration
• Impact damage
• Fatigue cycling

Thread Jump-Out

Thread jump-out results from:

• Excessive axial load
• Incorrect connection selection
• Insufficient thread engagement
• Damaged threads
• Improper makeup
• High bending load

BTC and higher-capacity connections provide improved resistance in heavily loaded casing strings.

External Wear

External coupling wear results from:

• Casing-to-wellbore contact
• Tubing-to-casing contact
• Deviated well geometry
• Running through restrictions
• Repeated workover cycles
• Inadequate clearance

Special-Clearance Couplings reduce external diameter where restricted clearance controls the connection design.

Manufacturing Quality Control

Goldenman coupling quality control includes:

• Raw-material certificate verification
• Heat-number traceability
• Chemical-composition verification
• Heat-treatment record review
• Mechanical-property testing
• Yield-strength testing
• Tensile-strength testing
• Elongation testing
• Impact testing
• Hardness testing
• Coupling OD inspection
• Coupling length inspection
• Bore-diameter inspection
• Bearing-face inspection
• Thread inspection
• Thread-gauge verification
• Surface-roughness inspection
• Magnetic-particle inspection
• Ultrasonic inspection
• Coating inspection
• Marking verification
• Final visual inspection

Coupled tubular assemblies undergo the specified drift, dimensional and hydrostatic testing program.

Product Documentation

The documentation package includes:

• Certificate of Conformity
• Product datasheet
• Material certificate
• EN 10204 3.1 certificate
• Chemical-composition report
• Heat-treatment record
• Mechanical-property report
• Impact-test report
• Hardness report
• Dimensional inspection report
• Thread-gauge inspection report
• MPI report
• UT report
• Surface-treatment report
• Coating report
• Heat and lot traceability list
• Packing list
• Third-party inspection report

Frequently Asked Questions

What is an API 5CT Coupling?

An API 5CT Coupling is an internally threaded seamless connector used to join two externally threaded casing or tubing joints.

What tubing coupling sizes are available?

Goldenman supplies tubing couplings in:

• 1.900 in
• 2-3/8 in
• 2-7/8 in
• 3-1/2 in
• 4 in
• 4-1/2 in

What casing coupling sizes are available?

Goldenman supplies casing couplings from 4-1/2 to 20 inches.

What is the difference between NUE and EUE?

NUE connects non-upset tubing ends and has a smaller coupling OD.

EUE connects externally upset tubing ends and provides increased connection strength.

Is NUE a Buttress connection?

No.

NUE is an API round-thread Non-Upset Tubing connection.

Buttress Thread is used for BTC Casing connections.

What is the difference between STC and LTC?

STC has shorter round-thread engagement.

LTC has longer engagement and increased tensile connection capacity.

What is the difference between LTC and BTC?

LTC uses API round threads.

BTC uses a buttress thread form designed for higher axial-load transfer.

Are the coupling and pipe grades the same?

The coupling material and heat-treatment package are matched to the pipe grade and connection-performance requirements specified in the order.

Are P110 and Q125 Couplings available?

Yes.

Goldenman supplies high-strength P110 and Q125 Casing and Tubing Couplings.

Are sour-service Couplings available?

Yes.

Sour-service configurations include L80 Type 1, C90, T95, C110, C125 and project-specific corrosion-resistant grades.

Are 13Cr Couplings available?

Yes.

Goldenman supplies L80 13Cr and other chromium-bearing Couplings for CO₂-resistant service.

What is a Special-Clearance Coupling?

A Special-Clearance Coupling has a reduced outside diameter for running through restricted annular or wellbore clearance.

Can a NUE Coupling be installed on EUE tubing?

No.

NUE and EUE use different pin ends, internal thread positions, coupling bores and outside dimensions.

Can STC and LTC Couplings be interchanged?

No.

STC and LTC use different thread engagement lengths and coupling dimensions.

Are Coupling Blanks available?

Yes.

Goldenman supplies Coupling Stock, rough-machined blanks, finished unthreaded blanks and fully threaded Couplings.

Are premium connection Couplings available?

Yes.

Goldenman manufactures premium-connection Coupling Blanks and finished Couplings from approved connection drawings and material specifications.

Information Required for Quotation

Please provide:

• Casing Coupling or Tubing Coupling
• Nominal pipe OD
• Nominal pipe weight
• Pipe wall thickness
• Steel grade
• NUE, EUE, STC, LTC or BTC connection
• Regular or Special Clearance Coupling
• Special-bevel requirement
• Coupling OD
• Coupling length
• Coupling only or Coupling Stock
• Finished or rough-machined blank
• Standard or sour service
• H₂S concentration
• CO₂ concentration
• Chloride concentration
• Minimum operating temperature
• Maximum operating temperature
• Heat-treatment requirement
• Surface treatment
• Thread compound
• Thread-protector type
• NDE requirements
• Third-party inspection
• Documentation requirements
• Required quantity
• Destination country
• Delivery schedule

Request a Technical Quotation

Goldenman supplies API 5CT Casing and Tubing Couplings for drilling, completion, production, injection and workover tubular strings.

The product range covers:

• 1.900–4-1/2-inch NUE and EUE Tubing Couplings
• 4-1/2–20-inch STC, LTC and BTC Casing Couplings
• J55, K55, N80, L80, P110 and Q125 grades
• Sour-service and corrosion-resistant materials
• Regular and Special-Clearance configurations
• Coupling Stock, Coupling Blanks and finished Couplings

Complete orders are supplied with material traceability, mechanical-property reports, thread-gauge inspection, NDE documentation, protective coatings and thread protectors.

Email: info@goldenman.com