Nickel Alloy Flanges

Product Overview

Hangbo Alloy Group manufactures forged nickel alloy flanges on open-die and closed-die presses from billet produced by vacuum induction melting (VIM) and electroslag remelting (ESR). Forging refines the grain structure and closes centre porosity, giving flange bodies with uniform through-thickness properties and no discontinuity at the hub-to-rim transition — the location where cast or plate-cut flanges most often fail.

Every flange is supplied solution-annealed, pickled and stamped to the applicable standard, with a heat number that traces back to the melt record. Dimensional inspection covers bore, bolt circle, hub diameter, flange thickness and facing finish; positive material identification (PMI) is performed on 100 % of pieces on request.

Flange Types and Pressure Classes

Type	Standard	Typical use
Welding Neck (WN)	ASME B16.5	High pressure, cyclic thermal duty
Slip-On (SO)	ASME B16.5	Low pressure, easy alignment
Socket Weld (SW)	ASME B16.5	Small bore, NPS 1/2 - 3
Lap Joint (LJ)	ASME B16.5	With stub end, frequent dismantling
Threaded (TH)	ASME B16.5	Non-welded, low pressure
Blind (BL)	ASME B16.5	Line termination, pressure test

Pressure classes 150, 300, 400, 600, 900, 1500 and 2500 are available in sizes from NPS 1/2 to NPS 24 to B16.5, and NPS 26 to NPS 60 to B16.47 Series A and B. Facing options include raised face (RF), flat face (FF), ring-type joint (RTJ) and tongue-and-groove.

Grades We Forge

• Inconel 625 (UNS N06625) — seawater, flue gas desulphurisation, acid gas
• Inconel 718 (UNS N07718) — high-strength sour service and subsea
• Hastelloy C-276 (UNS N10276) — mixed oxidising/reducing acids, wet chlorine
• Hastelloy C-22 (UNS N06022) — wider corrosion envelope, FGD absorbers
• Monel 400 (UNS N04400) — hydrofluoric acid, caustic, marine
• Incoloy 825 (UNS N08825) — sulphuric and phosphoric acid, sour gas

Material is supplied to ASTM B564 / ASME SB564 for nickel alloy forgings, with complementary certification to NACE MR0175 / ISO 15156 where the flange enters sour service. See our alloy knowledge centre for grade-by-grade corrosion data.

Quality and Documentation

• EN 10204 3.1 as standard; 3.2 with third-party witness (BV, SGS, TUV, DNV, Lloyd's) on request
• Full chemical analysis and room-temperature tensile per heat
• Ultrasonic testing to ASTM A388 and dye penetrant to ASTM E165
• PMI verification with XRF analyser, results recorded against heat number
• Hardness survey to NACE MR0175 limits for sour service flanges

Our in-house melting, forging and testing capability is described on the facilities page, and our quality approvals are listed under certifications.

What is the difference between ASTM B564 and ASME SB564 flanges?

They are technically identical specifications. ASTM B564 is the material specification for nickel alloy forgings; ASME SB564 is the same specification adopted into the ASME Boiler and Pressure Vessel Code. A flange ordered to SB564 is accepted for code-stamped vessels and piping.

Do you supply flanges with NACE MR0175 compliance?

Yes. For sour service we control chemistry, heat treatment and hardness so the finished forging meets NACE MR0175 / ISO 15156 limits, and we certify hardness survey results with the shipment.

Can you produce large-diameter or non-standard flanges?

Yes. Beyond the ASME B16.5 and B16.47 ranges we forge to customer drawings, including large-diameter ring flanges, tube-sheet forgings and integrally reinforced nozzles. Send the drawing and our engineers will confirm feasibility and lead time.