IBR Approved · Flanges
Pipe Flange Manufacturer
Weld neck, slip-on, blind, socket weld, lap joint and threaded flanges to ASME B16.5 / B16.47 — in carbon, alloy, stainless and duplex steel. Class 150 to 2500, RF / FF / RTJ. IBR approved, EN 10204 3.1 / 3.2 traceable.
Overview
Flanges provide bolted, gasketed connections that allow piping, valves and equipment to be assembled and dismantled without cutting. We manufacture the full range of forged flanges to ASME B16.5 (through 24") and ASME B16.47 Series A / B for larger diameters, in pressure classes 150 through 2500 and RF, FF and RTJ facings.
Flanges are forged to the applicable material specification (A105 carbon steel, A182 alloy and stainless, A182 F51/F53 duplex), supplied with EN 10204 3.1 or 3.2 test certificates and, for boiler and steam service, IBR Form IV (Part D) (formerly Form III-C) certification.
Flange Types & Standards
| Type | Standard | Typical Use |
|---|---|---|
| Weld Neck (WN) | ASME B16.5 / B16.47 | High pressure, cyclic & high-temp service |
| Slip-On (SO) | ASME B16.5 | Lower-pressure, easy-alignment service |
| Blind | ASME B16.5 / B16.47 | Sealing flanged openings & vessels |
| Socket Weld (SW) | ASME B16.5 | Small-bore high-pressure lines |
| Lap Joint (LJ) | ASME B16.5 | With stub ends, frequent dismantling |
| Threaded | ASME B16.5 | Non-welded, utility & instrument lines |
Available Material Grades
Flanges are forged from the equivalent grade to the buttweld fittings. Click a grade for full specification, chemistry and mechanical data:
Technical Specifications
| Parameter | Range |
|---|---|
| Size range | 1/2" to 24" (B16.5), 26" to 48"+ (B16.47) |
| Pressure classes | 150, 300, 600, 900, 1500, 2500 |
| Facings | Raised Face (RF), Flat Face (FF), Ring-Type Joint (RTJ) |
| Dimensional standard | ASME B16.5 / B16.47 Series A & B |
| Certification | EN 10204 3.1 / 3.2 · IBR Form IV (Part D) |
| Testing | PMI, dimensional, hardness, DP / UT as specified |
Testing & Inspection
- ✓ Chemical and mechanical testing against the ordered ASTM / ASME material specification
- ✓ PMI (positive material identification) and visual and dimensional inspection to ASME B16.5
- ✓ NDT (DP / MPI, UT or RT) as your specification requires
- ✓ EN 10204 3.1 certificate as standard; 3.2 witnessed by Bureau Veritas, TÜV, Lloyd’s Register, SGS, DNV or your own inspector
- ✓ IBR Form IV (Part D) for Indian boiler piping
Export Documents & Packing
- ✓ Commercial invoice, packing list and certificate of origin
- ✓ Heat-number traceability on every piece
- ✓ Seaworthy wooden cases or pallets, bevel ends protected, marked to your instructions
- ✓ FOB, CFR or CIF terms — see how an export order works
Frequently Asked Questions
What flange types do you manufacture?
We supply weld neck (WN), slip-on (SO), blind, socket weld (SW), lap joint (LJ) and threaded flanges to ASME B16.5 (1/2 inch to 24 inch) and ASME B16.47 Series A/B for larger diameters. Facings include raised face (RF), flat face (FF) and ring-type joint (RTJ), in pressure classes 150, 300, 600, 900, 1500 and 2500.
Which flange should I use — weld neck or slip-on?
A weld neck flange has a tapered hub butt-welded to the pipe and is preferred for high-pressure, high-temperature and cyclic service because it transfers stress smoothly and allows full radiography of the weld. A slip-on flange slides over the pipe and is fillet welded inside and out — cheaper and easier to align, suited to lower-pressure service. Both are supplied to ASME B16.5 across our full material range.
Which certificates and documents come with your flanges?
EN 10204 3.1 certificates as standard, 3.2 with third-party inspection, IBR Form IV (Part D) (formerly Form III-C) where the fittings are for Indian boiler piping, plus export documents: commercial invoice, packing list and certificate of origin.