Carbon steel socket weld flanges are used on small-diameter, high-pressure piping systems where butt welding is not practical. The pipe is inserted into the socket and fillet welded on the outside, creating a strong, leak-resistant joint with minimal crevice. Huaxia-Steel manufactures socket weld flanges in A105, A105N and A350 LF2 from Class 150 to Class 2500.
Product Overview
Socket weld flanges are compact and well-suited to high-pressure services because the socket provides good support to the pipe end. They are typically used for pipe sizes NPS ½ to NPS 4, especially in steam, chemical and hydraulic systems where vibration and fatigue are concerns.
Size and Specification
| Item | Specification |
|---|---|
| Standard | ASME B16.5 / B16.47 Series A |
| Material | ASTM A105, A105N, A350 LF2, A694 F52-F70 |
| Size | 1/2 inch – 4 inch (DN15 – DN100) |
| Class | 150, 300, 600, 900, 1500, 2500 |
| Facing | RF, RTJ, FF |
| Coating | Black paint, anti-rust oil, hot-dip galvanizing |
| Certificate | EN 10204 3.1, NACE MR0175 on request |
Dimensional Data (Class 300 RF, mm)
| Size | Bore | OD | Thickness | Bolt holes |
|---|---|---|---|---|
| 1/2 inch | 22.3 | 95 | 12.7 | 4×16 |
| 1 inch | 34.5 | 125 | 15.9 | 4×19 |
| 2 inch | 61.1 | 165 | 20.7 | 8×19 |
| 3 inch | 88.9 | 210 | 28.6 | 8×22 |
| 4 inch | 114.3 | 255 | 31.8 | 8×22 |
Installation Notes
Proper installation is critical for leak-free service. The pipe should be inserted fully to the bottom of the socket, then drawn back approximately 1.6 mm before welding to allow for thermal expansion. A 1.6 mm gap is standard for carbon steel socket welds to prevent cracking.
- Clean pipe and socket bore before welding.
- Use compatible low-hydrogen electrodes.
- Preheat A350 LF2 or thicker sections according to ASME IX.
- Perform visual and dye-penetrant inspection after welding.
- Apply post-weld heat treatment for severe service or thick sections.
Applications
- High-pressure steam and process lines.
- Chemical and petrochemical plants.
- Hydraulic and instrument tubing connections.
- Power plant piping systems.
- Oil and gas manifold and wellhead connections.
Quality Control
Flanges are forged or machined from killed carbon steel. Each batch is tested for chemical composition, hardness, dimensional compliance and surface finish. We provide material certificates, hydrostatic test reports and NACE compliance certificates on request.
Packing and Shipping
Flanges are packed in seaworthy wooden cases or pallets, separated by cardboard or plastic, with thread and facing protection. Marking includes size, class, material, heat number and standard.
Need a reliable carbon steel supplier for your next project? Huaxia-Steel supplies mill-certified carbon steel bars, plates, pipes, flanges and fittings with full inspection, export packing and fast delivery. Request a quote today and our team will reply within 24 hours.
