Monel 400 Forged Fittings are made to ASTM B564 / ASME SB564 UNS N04400 for seawater and HF acid service. Socket weld and threaded fittings are dimensioned to ASME B16.11 for small-bore Monel 400 piping.
Raaj Fittings manufactures Monel 400 forged fittings in-house at our two plants in India, from ⅛" to 4" in Class 2000 to 9000, 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 B564 / ASME SB564 UNS N04400 |
|---|---|
| Dimensional standard | ASME B16.11; MSS SP-79, SP-83, SP-95 and SP-97 |
| Size range | ⅛" to 4" NPS |
| Pressure class | Socket weld: Class 3000, 6000, 9000. Threaded: Class 2000, 3000, 6000 |
| Threads | NPT to ASME B1.20.1; BSPT / BSPP to BS 21 / ISO 7-1 |
| 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 |
In small-bore lines, the crevices of socket welds and threads are where corrosion starts. Monel 400 forged fittings keep the same corrosion resistance as the run pipe at those points. Use matching filler for socket welds and an anti-seize sealant on threads, as nickel alloys gall easily.
| Pipe | Socket weld class | Threaded class |
|---|---|---|
| SCH 80 / XS | 3000 | 2000 |
| SCH 160 | 6000 | 3000 |
| XXS | 9000 | 6000 |
Every heat is PMI-verified and its chemistry and mechanical properties are confirmed against the material specification before the forged 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.
Class 3000 socket weld fittings match SCH 80 pipe, Class 6000 matches SCH 160 and Class 9000 matches XXS. For threaded fittings, the matching classes are 2000, 3000 and 6000.
Every order is supplied with EN 10204 3.1 mill test certificates showing heat chemistry and mechanical properties to ASTM B564 UNS N04400. EN 10204 3.2 certification and inspection by your nominated third-party agency are available on request.