Socket Weld Flange
Product Description
1. Product Introduction
The Socket Weld Flange is specifically designed for small-bore, high-pressure piping systems where the mechanical strength of a Weld Neck Flangeis desired but the cost and space constraints of a full hub are unnecessary. The pipe end is inserted into the flange's socket bore — a machined counter-bore that leaves a small annular gap between the pipe OD and the socket ID — and then fillet-welded around the face of the pipe. The fillet weld at the pipe face is the primary strength member; a secondary seal is created by the interference fit between the pipe and the socket at the bottom of the counter-bore. The small annular gap inside the socket — typically 1.5mm — can trap the pipe's ID oxidation scale and is generally considered unsuitable for cyclic thermal service where the differential expansion of the pipe and flange could cause fatigue. For this reason, Socket Weld Flanges are specified primarily for non-cycling or moderate-service small-bore lines: hydraulic systems, instrument air, chemical feed lines, and utility connections. Their compact bore design provides a smooth, nearly full-bore flow path with minimal turbulence. The connection is permanent — once welded, it cannot be disassembled without cutting.
2. Product Features
- Sizes from 1/2" to 3" NPS — standard small-bore high-pressure range
- Pressure ratings up to CL1500 (ASME B16.5); PN10/PN16/PN40 for EN projects
- Socket bore with fillet weld creates strong, leak-resistant joint
- Compact hub design — lighter and more compact than Weld Neck flanges
- Near full-bore flow path minimizes turbulence and pressure loss
- RF, FF, and RTJ facing options
3. Core Specifications
|
Parameter |
Specification |
|
Size Range |
1/2" – 3" NPS |
|
Pressure Rating |
CL150 – CL1500; PN10/PN16/PN40 |
|
Facing |
RF (Raised Face), FF (Flat Face), RTJ (Ring Type Joint) |
|
Weld Configuration |
Socket bore with face fillet weld |
|
Flow Path |
Near full-bore — minimal turbulence and pressure loss |
|
Materials |
Carbon steel, alloy steel, stainless steel |
|
Standards |
ASME B16.5, AWWA C207, EN 1092-1 |
|
Certifications |
API, ISO 9001, ISO 14001, ISO 45001, CE |
4. Materials
- European: P235GH, P245GH, P265GH, P280GH for EN-standard piping
5. Product Standards
- ASME B16.5 — Pipe Flanges and Flanged Fittings (1/2" – 3")
- AWWA C207 — Steel Pipe Flangesfor Waterworks Service
6. Applications
- Small-bore hydraulic control lines in refinery and petrochemical process plants
- High-pressure instrument air and pneumatic control systems
- Chemical feed and dosing lines in water treatment and chemical processing
- Power plant auxiliary piping: lube oil, seal oil, and instrument air systems
- Oil and gas production hydraulic and chemical injection lines
- Compressed gas cylinders and manifold connections in industrial gas distribution
7. Packaging
8. Customization
Special bore tolerances, non-standard facing combinations, special alloys for corrosive chemical injection service, and orifice plate configurations for flow measurement applications.
For detailed specifications and applications, explore this product page.
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