Carbon steel socket weld half coupling is a high-pressure forged branch outlet fitting widely used in oil & gas pipelines, petrochemical processing units, power generation facilities, and industrial piping networks. Forged according to ASME B16.11 and BS 3799 standards, these fittings are designed for reinforcement or branch outlet connections on small bore pipelines, providing excellent mechanical strength, reliable sealing performance, and long-term operational safety.
Unlike threaded outlets, socket weld half couplings ensure stronger weld integrity and minimize leakage, making them the preferred solution in critical pipeline installations. Our A105 carbon steel SW half couplings are supplied globally for EPC contractors, refineries, and industrial pipeline projects.
Product Name: CS SW Half Coupling
Material: Carbon Steel ASTM A105, Low Temperature Carbon Steel ASTM A350 LF2, optional Alloy Steel F11/F22 or Stainless Steel F304/F316
Size Range: 1/8” – 4” (DN6 – DN100)
Pressure Rating: Class 3000 / 6000 / 9000
Standard: ASME B16.11, BS 3799
Connection Type: Socket Weld
Surface Finish: Black Painting, Anti-Rust Oil, Galvanized, Sandblasting
Inspection: Dimensional Verification, PMI, UT, MT as required
Key Features:
Compact and high-strength branch connection solution
Designed for small bore high-pressure systems
Excellent sealing and leak-free performance
Fully compliant with ASME B16.11 and BS 3799
Suitable for global piping codes and standards
Accurate dimensions are critical for proper fit-up during welding. Our SW half couplings cover the following standard ranges:
| NPS | Socket Bore (B) mm | Depth (J) mm | Socket DIA (D) mm | Wall THK (C) mm | Laying Length (E/F) mm |
|---|---|---|---|---|---|
| 1/2 | 21.95 | 21.70 | 16.6 | 4.65 | 22.5 |
| 3/4 | 27.30 | 27.05 | 21.7 | 4.90 | 23.5 |
| 1 | 34.05 | 33.80 | 27.4 | 5.70 | 29 |
| 1 1/4 | 42.80 | 42.55 | 35.8 | 6.05 | 30 |
| 1 1/2 | 48.90 | 48.65 | 41.7 | 6.35 | 32 |
| 2 | 61.35 | 61.10 | 53.5 | 6.95 | 41 |
| 2 1/2 | 74.20 | 73.80 | 64.2 | 8.75 | 42.5 |
| 3 | 90.15 | 89.80 | 79.5 | 9.50 | 44.5 |
| 4 | 115.80 | 115.45 | 103.8 | 10.70 | 47.5 |
Dimensional tolerances:
NPS 1/2 and 3/4 = ±1.5 mm, NPS 1 to 2 = ±2 mm, NPS 2 1/2 to 4 = ±2.5 mm
Internal link suggestion: Dimensions → Buying Guide module to guide procurement decisions.
Forged socket weld half couplings offer unmatched mechanical strength due to the closed die forging process, resulting in dense internal grain structure. This provides:
Superior fatigue resistance
High-pressure endurance
Compact design suitable for instrumentation piping
Reduced turbulence at branch connections
Reliable performance in small bore high-pressure applications
The robust structure ensures minimal maintenance and long-term service life even under vibration and thermal cycling.
Half Coupling:
Welded directly onto main pipe
Provides branch outlet or reinforcement
Suitable for small bore high-pressure pipelines
Full Coupling:
Connects two pipes inline
Used for pipe extension or repair
Suitable for larger diameter pipelines
Choosing the right coupling type is critical to ensure mechanical integrity and system reliability.
Socket Weld Coupling:
High-pressure service suitable
Stronger joint and reduced leakage
Handles vibration and pressure pulsation
Preferred for critical industrial applications
Threaded Coupling:
Lower pressure applications
Quick installation without welding
Not suitable for high vibration or cyclic load
Limited durability under industrial stress
Material selection is crucial for durability and compliance:
Carbon Steel: ASTM A105 (general high-pressure pipelines)
Low Temperature Carbon Steel: ASTM A350 LF2 (cryogenic or cold environment service)
Stainless Steel: ASTM A182 F304 / F316 (corrosion-resistant applications)
Alloy Steel: ASTM A182 F11 / F22 (elevated temperature service)
All materials come with EN 10204 3.1 Mill Test Certificates and full traceability documentation for EPC and industrial projects.
Raw material verification and chemical analysis
Closed die forging for dense grain structure
Heat treatment (normalizing, quenching, tempering)
CNC precision machining of socket bore and welding depth
Surface finishing: black painting, anti-rust oil, galvanizing
Dimensional inspection & NDT (UT/MT/PMI)
Internal link suggestion: Manufacturing Process → Quality Control → Buying Guide
Strict QC ensures compliance with ASME B16.11:
Dimensional verification
Chemical composition analysis
Ultrasonic Testing (UT)
Magnetic Particle Testing (MT)
Visual inspection
This guarantees every half coupling meets project requirements for safety and reliability.
Oil & gas transmission pipelines
Refinery process piping systems
Offshore platform instrumentation outlets
LNG skid and modular plant piping
Power plant high-pressure steam lines
Industrial chemical and utility pipelines
Internal link suggestion: Applications → EPC Project Supply → Request Quote
We support international projects with:
Bulk supply of forged SW half couplings
OEM and custom specifications
Export-grade packaging and documentation
Short lead time and reliable logistics
Perfect for EPC contractors requiring high-quality, traceable fittings for large-scale pipeline projects.
When choosing a forged socket weld half coupling manufacturer, consider:
Forging equipment and production capacity
CNC machining tolerances
NDT inspection capabilities
OEM customization options
Delivery performance and project support
Selecting the right supplier ensures safe pipeline installations and reduces project risk.
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Alt text: "Carbon Steel Socket Weld Half Coupling ASTM A105, Class 3000, 6000, 9000 for industrial pipelines"
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