Special flanges and vessel flanges to drawing
Forged flanges outside the standard — DN 15 to DN 4000, PN 6 to PN 400, single pieces included.
Standard flanges are available everywhere. It gets difficult as soon as the drawing departs from the standard: oversized nominal diameters, irregular bolt patterns, special materials, combined sealing faces, or vessel flanges to DIN 28030 for tank nozzles. Those parts are exactly our business — including single pieces, and including cases where only an old hand sketch survives.
We supply forged special flanges from DN 15 to DN 4000 and pressure ratings from PN 6 to PN 400, or Class 150 to 2500. Available as weld neck, blind, loose or fully custom flanges in carbon steel, creep-resistant steel, stainless steel or duplex. For standardised flanges and recurring requirements, see our standard parts programme.
Technical data
| Nominal size | DN 15 – DN 4000 |
|---|---|
| Pressure rating | PN 6 – PN 400 / Class 150 – 2500 |
| Piece weight | up to 12 t |
| Standards | EN 1092-1, ASME B16.5, ASME B16.47, DIN 28030 |
| Types | Weld neck, blind, loose, threaded and custom flanges |
| Sealing faces | Form B1/B2, RF, RTJ, tongue and groove, male and female |
| Testing | UT, MT, PT; pressure testing and PMI on request |
These are typical manufacturing ranges within our supplier network. Larger dimensions and special materials on request — send us your drawing.
Materials
- P250GH (1.0460)
- P355NH (1.0565)
- 16Mo3 (1.5415)
- 1.4404 / 316L
- 1.4571 / 316Ti
- 1.4462 duplex
Manufacturing and quality assurance
- Reconstruction of the geometry from a drawing, sample or old part — even without complete documentation.
- A forged blank rather than a flame-cut one: the grain flow follows the flange contour and carries the hub.
- Heat treatment according to grade and pressure rating, with documented temperature records for creep-resistant grades.
- Non-destructive testing of the sealing face and transition radius; PMI material verification on request.
- Inspection certificate 3.1 to EN 10204, PED-compliant documentation on request.
Typical applications
- Vessel and process equipment construction
- Valves and pipeline equipment
- Boilers and heat exchangers
- Chemical and process engineering
- Power generation
- Spare parts for existing plant
Frequently asked questions
What distinguishes a vessel flange from a standard flange?
Vessel flanges to DIN 28030 are designed for tank nozzles and differ from pipeline flanges to EN 1092-1 in hub thickness, bolt pattern and connection geometry. They are usually designed together with the vessel and are therefore rarely available from stock.
Do you make flanges from a sample or old part?
Yes. Where no drawing survives we measure the old part or work from your sketch and produce a manufacturing drawing for your approval. For spare parts on older plant this is the normal case.
Are single pieces possible?
Yes. Special flanges are open-die forged or made from forged stock, so no part-specific tooling cost arises. Quantity one is explicitly possible.
Which materials are available?
Carbon steels such as P250GH and P355NH, creep-resistant grades such as 16Mo3, stainless steels 1.4404 and 1.4571 and duplex 1.4462. Further materials including nickel-base alloys on request.
What is the lead time for a special flange?
Typically 6 to 14 weeks from release, depending on nominal size, material and testing scope. For shutdowns and repairs we check expedited handling.
Request a quote for Special flanges
Send us your drawing or specification. You get feedback on feasibility, material selection and an indicative price — from engineers, not from a call centre.
Send enquiry