Monel 400 Buttweld Fittings are made to ASTM B366 / ASME SB366 WPNC (UNS N04400) for seawater and HF acid service. Elbows, tees, reducers and caps are dimensioned to ASME B16.9 and bevelled for welding into Monel 400 pipe.
Raaj Fittings manufactures Monel 400 buttweld fittings in-house at our two plants in India, seamless and welded, from ½" upwards, and exports them to EPC contractors, fabricators and stockists across the Middle East, Europe and the Americas, with full traceability and EN 10204 certificates.
| Material specification | ASTM B366 / ASME SB366 WPNC (UNS N04400) |
|---|---|
| Construction | Seamless and welded |
| Dimensional standards | ASME B16.9, MSS SP-43; bevelled ends to ASME B16.25 |
| Size range | ½" to 48" NPS; larger sizes to order |
| Wall thickness | SCH 5S, 10S, 40S, 80S and heavier walls to order |
| Certification | EN 10204 3.1 mill test certificate as standard; EN 10204 3.2 on request |
Alloy 400 (UNS N04400) is a nickel-copper alloy with about 65% nickel and 30% copper. It is renowned for resisting fast-flowing seawater, hydrofluoric acid and alkalis, and it keeps good toughness from cryogenic temperatures to about 480 °C.
| Element, % | N04400 |
|---|---|
| Nickel (Ni, incl. Co) | 63.0 min |
| Copper (Cu) | 28.0 – 34.0 |
| Iron (Fe) | 2.5 max |
| Manganese (Mn) | 2.0 max |
| Carbon (C) | 0.3 max |
| Silicon (Si) | 0.5 max |
| Sulphur (S) | 0.024 max |
Mechanical properties are as required by the ordered ASTM specification and are reported on the mill test certificate.
| UNS | Werkstoff Nr. | EN / DIN | Other |
|---|---|---|---|
| N04400 | 2.4360 | NiCu30Fe | Monel® 400 |
Monel 400 fittings are formed from pipe, plate or bar and supplied in the solution-annealed condition. Light-wall schedules (5S, 10S, 40S) are common because the alloy's strength and corrosion resistance allow thin walls. Weld with matching nickel alloy filler and low heat input.
Every heat is PMI-verified and its chemistry and mechanical properties are confirmed against the material specification before the buttweld fittings are released. Each piece is marked with grade, size, rating and heat number for traceability to its EN 10204 3.1 mill test certificate. EN 10204 3.2 certification and inspection by the buyer's nominated third-party agency are available on request, as are PED 2014/68/EU compliance for European projects and IBR certification for Indian boiler applications.
Alloy 400 is one of the few materials with good resistance to hydrofluoric acid, so it is the standard choice for piping and fittings in refinery HF alkylation units.
Yes, especially flowing seawater. In stagnant seawater, crevices and deposits can cause pitting, so design and maintenance should avoid stagnant conditions.
Yes. Smaller sizes are normally seamless and larger sizes welded, with weld examination as the specification and your order require. Tell us the size, schedule and any construction requirement.
Every order is supplied with EN 10204 3.1 mill test certificates showing heat chemistry and mechanical properties to ASTM B366 WPNC (UNS N04400). EN 10204 3.2 certification and inspection by your nominated third-party agency are available on request.