Specifications
Surface Treatments
Certifications
- ISO 9001 - 2015 Certified
- PED 2014/68/EC
- NACE MR0175/ISO 15156-2
- NORSOK M-650
- DFAR
- MERKBLATT AD 2000 W2/W7/W10
Monel 400 Flanges - UNS N04400 ASTM B564 / ASME B16.5 / B16.47
Monel 400 flanges (also Monel 400 flange, Alloy 400 flange, UNS N04400 flange, Werkstoff 2.4360 flange) are forged to ASTM B564 and dimensioned per ASME B16.5 (NPS 1/2 to 24) or ASME B16.47 Series A / B (NPS 26 to 60). Pressure classes 150, 300, 600, 900, 1500, 2500; face types RF, FF, RTJ with grooves per ASME B16.20. Forms: WN, SO, BL, LJ, SW, THD. Used on HF acid piping, HF alkylation joints, seawater coolers and marine systems. Alloy is UNS N04400; chemistry matches B164 bar and B127 plate. Monel® is a registered trademark of Special Metals Corporation; TorqBolt is not authorized by, affiliated with or endorsed by Special Metals.
Standards Stack
A three-standard part: material to ASTM B564, dimensions to ASME B16.5 or B16.47, gasket grooves to ASME B16.20.
| Standard | Scope | Covers |
|---|---|---|
| ASTM B564 | Material | Forged Ni-alloy parts in UNS N04400 |
| ASME B16.5 | Dimensions | NPS 1/2 to 24; classes 150 to 2500; P-T ratings |
| ASME B16.47 Series A | Dimensions | NPS 26 to 60 (ex MSS SP-44); refinery, offshore |
| ASME B16.47 Series B | Dimensions | NPS 26 to 60 (ex API 605); lighter, legacy |
| ASME B16.20 | Gaskets | Spiral-wound, kammprofile, RTJ ring grooves |
| NACE MR0175 | Sour service | N04400 hardness ceiling 35 HRC |
| EN 10204 | Cert | 3.1 mill MTC; 3.2 third-party witness |
B16.5 P-T ratings sit in Material Group 3.2; derates above 150 C versus A105.
Pressure Class Range
Six ASME B16.5 classes; class 150 for low-pressure water and caustic, class 600 to 900 for refinery, class 1500 and 2500 for HF alkylation headers and offshore wellhead piping.
| Class | PN | 38 C (bar) | 200 C (bar) | Service |
|---|---|---|---|---|
| 150# | PN 20 | 19.6 | 13.8 | Brackish water, caustic, dilute HF |
| 300# | PN 50 | 51.1 | 43.4 | Refinery overheads, seawater |
| 600# | PN 100 | 102.1 | 86.8 | HF storage, sour-water strippers |
| 900# | PN 150 | 153.2 | 130.2 | HF alkylation acid, sour-gas separator |
| 1500# | PN 250 | 255.3 | 217.0 | Offshore wellhead, high-pressure sour |
| 2500# | PN 420 | 425.5 | 361.6 | Deepwater spools, NORSOK L-001 class 6 |
Verify each project against ASME B16.5 Table 2-3.2 for the design temperature. Hydrotest at 1.5x class rating per B16.5 paragraph 2.6.
Face Types - RF, FF, RTJ
The face type is the sealing geometry. Pick once, hold across the spec.
| Face | Geometry | Gasket | Class |
|---|---|---|---|
| Raised Face (RF) | 1.6 mm raised (class 150 / 300); 6.4 mm (class 400 plus) | Spiral-wound, kammprofile | 150 to 600 |
| Flat Face (FF) | Full-face flat, no seat | Full-face graphite or PTFE | 150 |
| Ring-Type Joint (RTJ) | Octagonal or oval groove per B16.20 | Monel 400 ring, R-series | 900 to 2500 |
RF default through class 600. Above class 600 the RTJ takes over: the Monel 400 ring deforms into the octagonal groove and seals metal-to-metal. Mating ring must be the same metallurgy.
Flange Types - WN, SO, BL, LJ, SW, THD
Six geometry options per ASME B16.5. Selection driven by piping spec, weld access and hydrotest class.
| Type | Code | Where used |
|---|---|---|
| Weld-Neck | WN | Default class 600 plus; HF, sour, hydrogen |
| Slip-On | SO | Class 150 and 300; low-cycle, easier alignment |
| Blind | BL | Vessel manways, terminations, future tie-ins |
| Lap-Joint | LJ | Frequent disassembly; mixed-metallurgy seawater intake |
| Socket-Weld | SW | NPS 2 and under, instrument tie-ins |
| Threaded | THD | Utility air, instrument; not HF or sour |
The lap-joint is the mixed-metallurgy move: a Monel 400 stub end welds to the Monel pipe, a carbon-steel backing ring carries the bolt load, and the bolt-up zone never touches the process fluid.
Size Range
ASME B16.5 covers NPS 1/2 to 24; NPS 26 to 60 moves to ASME B16.47 Series A or B. Below NPS 1/2 the part runs as fitting per ASME B16.11.
| Size band | Standard | Classes | Mill route |
|---|---|---|---|
| NPS 1/2 to 24 | ASME B16.5 | 150 to 2500 | Closed-die forged from B564 billet, ex-stock |
| NPS 26 to 60 Series A | ASME B16.47 | 150 to 900 | Ring-rolled or open-die, on indent |
| NPS 26 to 60 Series B | ASME B16.47 | 150 to 900 | Ring-rolled or open-die, on indent |
| NPS over 60 | Customer drawing | Engineered | Open-die forged or fabricated |
Tolerance class per B16.5 Table 8; bolt circle, bolt count and raised-face diameter tabulated by class. RTJ groove dimensions per B16.20 Tables 4 to 7 by R-series ring number.
Chemistry per ASTM B564
B564 Table 1 fixes the chemistry; PMI at receipt verifies Ni and Cu. Matches B164 rod and B127 plate.
| Element | UNS N04400 (wt %) |
|---|---|
| Nickel (Ni) | 63.0 min |
| Copper (Cu) | 28.0 to 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 |
Free-machining R-405 (UNS N04405) at 0.025 to 0.060 percent S is bar only; B564 does not list R-405 for forgings. See chemical composition.
Mechanical Floor and Sour-Service
B564 hot-worked annealed holds the same floor as B127 plate. Hardness sits well below the NACE MR0175 / ISO 15156-3 ceiling of 35 HRC for nickel-copper; the flange clears the sour gate by design.
| Property | B564 annealed | NACE MR0175 |
|---|---|---|
| Tensile, min | 70 ksi (480 MPa) | ... |
| Yield 0.2% offset, min | 28 ksi (193 MPa) | ... |
| Elongation in 2 in., min | 35% | ... |
| Hardness, typical | 110 to 149 HBW | 35 HRC max |
| Charpy V at RT | typical > 200 J | Project-specified |
Sour shipments: EN 10204 type 3.2 plus NACE statement, heat-treat condition and hardness on the MTC. ASME Section VIII allowable stress per BPVC Section II Part D, SB-564. See mechanical properties and sour service.
Companion Piping
Pair every wetted component to the same nickel-copper metallurgy to avoid galvanic step.
| Component | Standard | Grade |
|---|---|---|
| Stud bolts | F468 Class A | F 468U, N04400; 25 HRC max |
| Heavy hex nuts | F467 | F 467U; heavy hex default |
| Washers | F436 / DIN 125 | N04400; through-hardened class 1500 plus |
| Spiral-wound gasket | B16.20 | Monel 400 winding + graphite filler |
| Kammprofile gasket | B16.20 | Monel 400 core + graphite facing |
| RTJ ring | B16.20 | Monel 400, R-series, octagonal |
| Butt-weld fittings | ASTM B366 | WPNC; see fittings |
| Pipe / tube | B165 / B163 | See pipe, tubing |
Tightening per ASME PCC-1 cross-pattern at 50 to 60 percent of F468 yield on hot service. See bolts and stud bolts for torque data.
Certification and Traceability
Every flange carries a stamp: heat number, B564, N04400, class, face, size, manufacturer. Low-stress dot-peen on the OD per B16.5 paragraph 4.4; never on the raised face.
| Certificate | Use |
|---|---|
| EN 10204 type 3.1 | Heat-specific MTC; commercial refinery, marine |
| EN 10204 type 3.2 | 3.1 plus third-party witness; NACE sour, NORSOK, nuclear |
| PMI report | XRF / OES verification of Ni and Cu |
| Hardness report | Brinell on hub and raised face; sour compliance |
| Hydrotest report | Shell test at 1.5x class; class 900 plus |
Traceability: heat to billet to forging to drawing item to fabricated piping, preserved on the MTC and stamp. See data sheet and specifications.
Frequently Asked Questions
Pressure class? ASME B16.5 classes 150 to 2500 (NPS 1/2 to 24); B16.47 Series A or B classes 150 to 900 (NPS 26 to 60). Group 3.2 P-T derates above 150 C; class often stepped up on hot HF.
RF or RTJ? RF default through class 600 with spiral-wound or kammprofile gaskets per B16.20. RTJ takes over from class 900 upward; the Monel 400 ring seals metal-to-metal. FF only for cast-iron and FRP counter-faces.
B16.5 vs B16.47? B16.5: NPS 1/2 to 24, classes 150 to 2500. B16.47: NPS 26 to 60, classes 150 to 900. Series A (heavier, refinery default) and Series B (lighter, legacy) are not interchangeable at the same NPS and class.
NACE certification? Yes for H2S above ISO 15156-3 thresholds. Annealed B564 at 110 to 149 HBW sits well below 35 HRC. Sour shipments ship EN 10204 type 3.2 plus NACE statement, hardness and heat-treat condition on the MTC. See sour service.
Related Pages
Standards: B564, B164, B127, B165, F468, F467, NACE MR0175, DIN 17743. Forms: forging, fittings, plate, round bar, pipe, tubing, sheet. Fasteners: bolts, stud bolts, heavy hex nuts, washers. Properties: chemistry, mechanical, corrosion, HF acid. Applications: HF alkylation, sour service, marine, what is Monel 400, UNS N04400, vs stainless, data sheet, specifications, pricing, main reference.
Request a Quote. For Monel 400 flanges to ASTM B564, UNS N04400, ASME B16.5 / B16.47, class 150 to 2500, RF / FF / RTJ face, WN / SO / BL / LJ / SW / THD form, EN 10204 type 3.1 or 3.2 MTC: send drawing, class, size and quantity to info@torqbolt.com or WhatsApp +91-22-66157017. Mumbai ex-stock price within one working day. Export through JNPT.
References. ASTM B564 Tables 1 and 2. ASME B16.5 (NPS 1/2 to 24). ASME B16.47 Series A and B (NPS 26 to 60). ASME B16.20. ASTM F468. ASTM F467. NACE MR0175 / ISO 15156-3. EN 10204. ASME BPVC Section II Part D. ASME PCC-1.
Satisfaction Survey
