Socket Weld Flange (SW Flange)
Engineering definition, metallurgical mechanisms, standard testing specifications, and manufacturing guidelines for closed-die forgings up to 50 kg.
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A forged pipe flange with a recessed counterbore socket that seats small-bore pipe, secured with a single external fillet weld.
Technical Explanation & Metallurgical Principles
Socket weld flanges (SW) are engineered specifically for small nominal pipe sizes (NPS 1/2" to 2") operating under high pressure. A 1/16" (1.6mm) thermal expansion gap is left between the pipe end and socket bottom prior to fillet welding to prevent thermal expansion cracking.
Key Engineering Specifications & Parameters
| Technical Parameter / Metric | Engineering Benchmark / Value |
|---|---|
| Size Scope | NPS 1/2" to 2" (DN 15 to DN 50) |
| Expansion Gap | Approx. 1.6 mm (1/16") before welding |
| Pressure Scope | Class 150# to 1500# |
Application at Jayesh Forge (Rajkot Plant)
Forged in Rajkot from A105, A350 LF2, and SS 316L up to 50 kg for chemical instrument headers and high-pressure hydraulic lines.
Related Materials, Standards & Products
Engineered Product Lines
Related Metallurgical & Testing Terms
Weld Neck Flange (WN Flange)
The premier high-integrity forged flange configuration featuring a long, tapered circular hub that butt-welds seamlessly to process pipe.
Slip-On Flange (SO Flange)
A forged pipe flange designed to slide over the outer diameter of process pipe and be secured using two fillet welds (one internal and one external).
ASME B16.5 Pipe Flanges Standard
The definitive American standard covering pressure-temperature ratings, materials, dimensions, tolerances, marking, and testing for pipe flanges NPS 1/2 through NPS 24.
Questions Regarding Socket Weld Flange (SW Flange)
Without the 1.6mm gap, weld shrinkage and thermal expansion of the pipe bottoming out against the socket shoulder can crack the fillet weld root.
Request a Forging Quote with Socket Weld Flange (SW Flange) Compliance
Our Rajkot metallurgy desk is ready to review your technical drawings, testing protocols, and delivery schedules for custom closed-die forgings strictly up to 50 kg.