Inconel 825 Expander FlangeASTM B564 · ASME B16.5 (flange end) · Manufacturer, stockist & exporter, India
Incoloy 825 · Alloy 825 · EXP
An Inconel 825 expander flange is a weld neck flange whose hub increases the pipe size, made from Inconel 825 to ASTM B564. Expander flanges step up the line size at a pump or valve outlet, replacing a reducer and a standard weld neck flange with one part.
- ASTM B564
- ASME B16.5 (flange end)
- EN 10204 3.1 / 3.2
- Export packing
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
What is an Inconel 825 Expander Flange?
- What it is
- A weld neck flange whose hub increases the pipe size
- Material
- ASTM B564
- Dimensions
- ASME B16.5 (flange end)
- Grade
- Inconel 825 · UNS N08825
- Best at
- Sulphuric and phosphoric acid service, chloride stress-corrosion cracking and sour gas
Inconel 825 Expander Flange Specification
| Product | Inconel 825 Expander Flange |
|---|---|
| Material standard | ASTM B564 |
| Dimensional standard | ASME B16.5 (flange end) |
| Sizes | ½" – 24" (ASME B16.5) · 26" – 60" (ASME B16.47) |
| Pressure class | Class 150, 300, 400, 600, 900, 1500, 2500 · PN 6 – PN 100 |
| Facing | RF · FF · RTJ · tongue & groove |
| Bore | To match pipe schedule (state on order) |
| Testing | PMI · dimensional · NDT and IGC on request |
| Documents | EN 10204 3.1 · 3.2 with third-party inspection |
When to Choose an Expander Flange
Expander flanges step up the line size at a pump or valve outlet, replacing a reducer and a standard weld neck flange with one part.
- Increases one or two pipe sizes
- Saves a weld and space
- Weld neck design
More on choosing: Expander flange guide.
Inconel 825 Expander Flange: Why 825 for expander flanges
Expander flanges step up the line size at a pump or valve outlet, replacing a reducer and a standard weld neck flange with one part. In Inconel 825, the choice usually comes down to the medium and temperature — the rows here are the points buyers check for this exact combination.
| Why this grade | Nickel-alloy flanges are used where acids, chlorides or heat defeat stainless. Inconel 825 is picked for sulphuric and phosphoric acid service, chloride stress-corrosion cracking and sour gas. |
|---|---|
| Typical service | Sulphuric & phosphoric acid plants — Tank linings, agitators, heat-exchanger baffles in fertiliser and acid production. |
| B16.5 material group | 3.8 — B16.5 does not permit N08825 above 538 °C. |
| Bolting | B7 (coated), B8M or nickel-alloy studs such as Inconel 825 from ASTM B425, as the project specifies |
| Welding to carbon steel | A nickel-base filler such as ERNiCr-3 (or ERNiCrMo-3) is used when joining it to carbon steel |
| Matching filler | ERNiFeCr-1 (AWS A5.14) |
| Sour service | Listed in NACE MR0175 / ISO 15156-3 within its limits — state it on the order |
Inconel 825 Expander Flange Chemical Composition
| Element | Weight % |
|---|---|
| Nickel | 38.0 – 46.0 |
| Iron | 22.0 min |
| Chromium | 19.5 – 23.5 |
| Molybdenum | 2.5 – 3.5 |
| Copper | 1.5 – 3.0 |
| Titanium | 0.6 – 1.2 |
| Carbon | 0.05 max |
| Manganese | 1.0 max |
Inconel 825 Expander Flange Mechanical Properties
| Annealed | Value |
|---|---|
| Tensile strength | 586 MPa · 85 ksi |
| Yield strength 0.2% | 241 MPa · 35 ksi |
| Elongation | 30% |
Full chemistry, properties and equivalents are on the Inconel 825 grade page.
Other Inconel 825 flanges
Inconel 825 Expander Flanges for export
FOB / CIF · Nhava Sheva (JNPT), MumbaiInconel 825 Expander Flange — questions buyers ask
When is an expander flange used?
Most often at pump and valve outlets where the line size increases immediately.
What pressure rating does a Inconel 825 expander flange have?
It depends on class and temperature. Inconel 825 forgings are in ASME B16.5 material group 3.8; read your class column in that group's table at the design temperature.
Can Inconel 825 expander flanges be welded to carbon steel?
Yes — a nickel-base filler such as ERNiCr-3 (or ERNiCrMo-3) is used when joining it to carbon steel.
Which standard covers Inconel 825 expander flanges?
The material is ASTM B564; dimensions follow ASME B16.5 (flange end). Always state both on your purchase order, with the edition if your project specifies one.
What decides the price of a Inconel 825 expander flange?
The alloy price, the size and pressure class, quantity, and the testing and documents required. Send your list and we quote the same working day.
Can you supply Inconel 825 expander flanges to NACE MR0175?
Yes. Inconel 825 is listed in NACE MR0175 / ISO 15156-3 within its limits; state NACE compliance on the order and it is confirmed on the certificate.
What documents do you supply?
EN 10204 3.1 mill certificates as standard, 3.2 with third-party inspection on request, plus dimensional and PMI reports.
Sources: the ASTM / ASME specifications named on this page and producer datasheets · Last updated October 2026