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
Incoloy 800H Flanges
TorqBolt-manufactured Incoloy 800H flanges (UNS N08810, Werkstoff 1.4876) are machined to ASME B16.5 dimensions in NPS 1/2 inch through 24 inch and pressure classes 150, 300, 600, 900, 1500 and 2500, forged from ASTM B564 / ASME SB-564 stock at the Rajkot plant. Flange types in regular production include weld-neck (WN), slip-on (SO), blind (BL), lap-joint (LJ), threaded (TH) and ring-type-joint (RTJ) with raised-face, flat-face, ring-joint, large-male-female and tongue-and-groove facings to suit high-temperature petrochemical, reformer and ASME Section VIII vessel service to 815 deg C (1500 deg F). Each flange is supplied with a default EN 10204 type 3.1 certificate covering heat-number chemistry, solution-anneal cycle at 2050 deg F, room-temperature mechanical results, hardness, dimensional report to B16.5 and a B16.34 pressure-temperature rating cross-reference. Type 3.2 third-party witness certification is available for refinery, LNG and subsea applications on call-out.
Flange Dimensions and Tolerances per ASME B16.5
The table below summarises the size and class envelope at the TorqBolt Rajkot plant. Dimensional tolerances follow ASME B16.5 paragraph 6 (raised-face height, outside diameter, bolt-circle, drilling, hub length). Raised-face finish is supplied as standard 125 to 250 AARH (stock-removal allowance for site grinding) or smooth 32 to 63 AARH on call-out for spiral-wound gasket service.
| Flange property | Specification / range |
|---|---|
| Pipe size range (NPS) | 1/2 inch to 24 inch (DN 15 to DN 600) |
| Pressure class | 150, 300, 600, 900, 1500, 2500 |
| Flange face types | RF (raised-face), FF (flat-face), RTJ (ring-joint), LMF (large male-female), T&G (tongue-and-groove) |
| Flange end types | WN (weld-neck), SO (slip-on), BL (blind), LJ (lap-joint), TH (threaded), SW (socket-weld) |
| RF height (class 150 / 300) | 1.6 mm (1/16 inch) per ASME B16.5 |
| RF height (class 600 to 2500) | 6.4 mm (1/4 inch) per ASME B16.5 |
| RTJ groove (R-type ring) | Per ASME B16.20 - R / RX / BX nomenclature |
| Surface finish (RF / FF default) | 125 to 250 AARH (3.2 to 6.3 micron Ra) |
| Surface finish (smooth on request) | 32 to 63 AARH (0.8 to 1.6 micron Ra) |
Flange Manufacturing Route at TorqBolt
Flange manufacture at the Rajkot plant runs through a seven-station route from B564 forged blank to packed and crated finished flange. The traveller links every piece back to a single heat number for traceability under ASTM B564 and ASME Section VIII Division 1.
- Forged blank receipt: Incoloy 800H disc or ring blank from in-house forging (see forgings) per ASTM B564, chemistry verified to B564 ranges, heat number and traceability records secured.
- Rough machine: Vertical lathe and 4-axis milling rough out flange OD, ID, hub profile and bolt-circle. Machining allowance 2 to 4 mm/side retained for finish.
- Solution anneal: 2050 deg F (1121 deg C) soak, accelerated air cool per ASTM B564 acceptance heat treatment. Grain size 5 or coarser confirmed per ASTM E112 on sacrificial coupon.
- Finish machine: CNC vertical and horizontal centres machine raised-face, bolt-circle, drilling, hub length, bore and finish RF to 125 to 250 AARH.
- Bolt-hole drilling: Multi-spindle drilling head per B16.5 drilling template; deburr per ASME B16.5 paragraph 6.
- NDT + dimensional: Liquid penetrant per ASTM E165, hardness per ASTM E18, full dimensional inspection per B16.5 with calibrated gauges, RF finish profilometer check.
- Marking + protection: Heat-number, grade ("UNS N08810 B564"), size, class, face type, manufacturer mark per MSS SP-25 low-stress stamped on OD. RF protected with disc and waterproof tape; crate with desiccant for sea freight.
Sizes Stocked and Lead Times
| Flange size + class | Stock status | Lead time (after PO) |
|---|---|---|
| NPS 1/2 to 4 inch, class 150 / 300, WN-RF | Held in B564 blank stock | 3 to 4 weeks |
| NPS 6 to 12 inch, class 150 / 300 / 600, WN-RF or SO-RF | Held in B564 blank stock | 4 to 6 weeks |
| NPS 14 to 24 inch, class 150 to 1500 | Forged on order | 8 to 10 weeks |
| RTJ flanges all sizes | Forged on order | 6 to 10 weeks |
| Class 2500 high-pressure | Forged on order | 10 to 14 weeks |
Flange-Specific Inspection and Marking
The flange inspection plan combines dimensional verification to ASME B16.5 with NDT and certification dictated by the pressure class and service temperature. Each flange is supplied with a B564 type 3.1 certificate as default; type 3.2 third-party witness inspection by Lloyds Register, DNV, BV, SGS or TUV is supplied on call-out.
- Dimensional: OD, ID, hub length, bolt-circle diameter, hole diameter, drilling pattern, raised-face height, all per ASME B16.5 paragraph 6.
- Surface finish: Profilometer check on RF - confirm 125 to 250 AARH for standard, 32 to 63 AARH for smooth-finish.
- Liquid penetrant per ASTM E165 on raised-face, hub fillet, weld-prep bevel. No linear above 1.6 mm.
- Hardness per ASTM E18 - Rockwell B 70 to 90 in solution-annealed condition.
- Marking: Heat number, B564 grade, size, class, face type, manufacturer mark per MSS SP-25 standard, plus the project tag number on call-out.
- Certification: EN 10204 type 3.1 default; type 3.2 with witness on call-out; PED 2014/68/EU Annex I certificate for pressure-equipment-directive scope.
Typical Flange Service Conditions
Incoloy 800H flange specifications appear most often on ethylene cracker outlet manifold piping, reformer pigtail tie-in spools, fired-heater inlet/outlet headers, steam superheater drum nozzles and ASME Section VIII high-temperature pressure-vessel man-ways. The pressure class is chosen by cross-referencing the ASME B16.5 pressure-temperature rating curve at the design temperature with the design pressure (see the ASME design stress tables for the parent material allowable stress).
| End-use flange | Design temperature | Typical class | Companion application |
|---|---|---|---|
| Ethylene cracker outlet manifold | up to 1050 deg C tube-skin | 150 / 300 | Ethylene cracker tubes |
| Reformer pigtail tie-in | 815 to 900 deg C | 300 / 600 | Reformer pigtails |
| Fired-heater header nozzle | 650 to 815 deg C | 600 / 900 | Radiant tubes |
| Steam superheater drum nozzle | 540 to 650 deg C | 900 / 1500 | Steam superheaters |
| ASME Section VIII vessel man-way | up to 815 deg C | per UG-22 design | ASME VIII vessels |
Companion Forms and Bolt-up Reference
Incoloy 800H flanges are typically procured alongside matching buttweld and socketweld fittings for the spool fabrication, seamless pipe as the run, and forged stud bolts and heavy hex nuts in matching B408 or B564 chemistry for the bolted joint. For high-temperature bolt stress relaxation and torque-tension behaviour, see the bolt dimensions reference. Welded spools should follow the 800H weldability procedures.
Flanges FAQ
Q. Are Incoloy 800H flanges interchangeable with carbon steel ASME B16.5 flanges of the same class?
The bolt-circle, drilling and gasket-face geometry are interchangeable per ASME B16.5. The pressure-temperature rating of the 800H flange follows the ASME B16.34 stress table for UNS N08810 and is higher than the ASTM A105 carbon steel rating at temperatures above 425 deg C. Below 425 deg C the carbon steel rating may exceed the nickel-alloy rating.
Q. What gasket is recommended on an 800H raised-face flange in high-temperature service?
For service above 540 deg C, a spiral-wound gasket with Inconel 625 or 800H winding and graphite or mica filler is standard. PTFE-filled spiral-wound gaskets are limited to 260 deg C and not used in 800H high-temperature service. For RTJ flanges, soft-iron rings are avoided above 540 deg C and 304L stainless or 800H rings are specified instead.
Q. Do you supply 800H flanges with PED 2014/68/EU certification?
Yes. TorqBolt is PED 2014/68/EU certified for pressure equipment categories and we supply flanges with the Annex I conformity-assessment certificate signed by a Notified Body. The PED certificate is issued in addition to the EN 10204 type 3.1 or 3.2 material certificate.
Q. What surface finish should I specify for a soft-iron RTJ ring on an 800H flange?
RTJ groove flank finish is supplied at 63 AARH (1.6 micron Ra) maximum per ASME B16.20 to ensure proper seating of the soft-iron ring without scuffing the 800H groove flank. For higher service temperature, a 304L or 800H ring is preferred over soft iron.
Q. Can you machine a custom non-standard flange (not in B16.5) from 800H forging?
Yes. Custom flanges to API 6A, API 6BX, Norsok L-005 or customer-specific drawing are forged from B564 stock, solution-annealed and finish-machined to the project drawing. Lead time is 8 to 12 weeks depending on flange size.
Request a Quote on Incoloy 800H Flanges
Send the project line-list, NPS, pressure class, face type (RF / RTJ / FF), end type (WN / SO / BL), surface finish, quantity, ASTM B564 grade, certification class (EN 10204 3.1 or 3.2) and any PED, NACE MR0175 or fire-safe (API 6FB) add-ons to our sales desk.
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