Monel 400 Expander FlangeASTM B564 · ASME B16.5 (flange end) · Manufacturer, trader & exporter, India
Alloy 400 · UNS N04400 · EXP
A Monel 400 expander flange is a weld neck flange whose hub increases the pipe size, made from Monel 400 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 a Monel 400 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
- Monel 400 · UNS N04400
- Best at
- Seawater, hydrofluoric acid and marine service
Monel 400 Expander Flange Specification
| Product | Monel 400 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 (as specified in the PO) · dimensional · NDT and IGC on request |
| Documents | EN 10204 3.1 or 3.2 on request / as specified in the PO |
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.
Monel 400 Expander Flange: Why 400 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 Monel 400, 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. Monel 400 is picked for seawater, hydrofluoric acid and marine service. |
|---|---|
| Typical service | Marine — Pump shafts, valves and seawater piping. |
| B16.5 material group | 3.4 |
| Bolting | B7 (coated), B8M or nickel-alloy studs in Monel 400 (bar to ASTM B164, where applicable), 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 | ERNiCu-7 (AWS A5.14) |
| Sour service | Listed in NACE MR0175 / ISO 15156-3 within its limits — state it on the order |
Monel 400 Expander Flange Chemical Composition
Under technical review for TDS.
| Element | Current requirement |
|---|---|
| Nickel (+Co) | As specified |
| Copper | As specified |
| Iron | As specified |
| Manganese | As specified |
| Carbon | As specified |
| Silicon | As specified |
| Sulphur | As specified |
Numerical specification requirements are published only after the applicable current standard edition has been verified. Governing specification to be verified: ASTM B127 for UNS N04400.
Monel 400 Expander Flange Mechanical Properties
Under technical review for TDS.
| Property | Current requirement |
|---|---|
| Tensile strength | As specified |
| Yield strength 0.2% | As specified |
| Elongation | As specified |
Numerical specification requirements are published only after the applicable current standard edition has been verified. Governing specification and condition to be verified: ASTM B127 for UNS N04400 — Annealed plate.
Full chemistry, properties and equivalents are on the Monel 400 grade page.
Other Monel 400 flanges
Monel 400 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 Monel 400 expander flange have?
It depends on class and temperature. Monel 400 forgings are in ASME B16.5 material group 3.4; read your class column in that group's table at the design temperature.
Can Monel 400 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 Monel 400 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 Monel 400 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 Monel 400 expander flanges to NACE MR0175?
Yes. Monel 400 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 or 3.2 certificates available on request / as specified in the PO; dimensional reports as required. PMI can be arranged depending on product and requirements, as specified in the PO.
Sources: the ASTM / ASME specifications named on this page and producer datasheets · Last updated October 2026