Tesco Steel & Engineering manufactures Hastelloy C22 flanges (UNS N06022 / W.Nr. 2.4602) — the high-chromium nickel-chromium-molybdenum superalloy with ~56% Ni, ~22% Cr, ~13% Mo and ~3% tungsten. C22 is exceptionally versatile across both oxidizing and reducing media, with outstanding resistance to pitting, crevice corrosion, chloride stress-corrosion cracking and mixed acids — outperforming C276 in strongly oxidizing service. Available in weld neck, slip-on, blind, socket-weld, threaded, lap-joint, spectacle and orifice types to ASTM B564 / ASME B16.5. Class 150 to 2500, NPS 1/2″ to 24″, PN6 to PN400. ISO 9001:2015 certified. Made in India.
Hastelloy C22 (UNS N06022) Flanges
Hastelloy C22 Threaded Flange (Polished)
Tesco Steel & Engineering manufactures C22 flanges in all types from weld neck to orifice, Class 150 to 2500 — supplied with EN 10204 3.1 / 3.2 certification, PMI and third-party inspection on request. Explore the wider Hastelloy flange range, the closely-related Hastelloy C276 flanges, and the flange dimension charts.
| Hastelloy C22 flanges are available in the following specifications: | |
|---|---|
| Material Grade | Hastelloy C22 / UNS N06022 / W.Nr. 2.4602 (NiCr21Mo14W) |
| Alloy Type | Nickel-chromium-molybdenum superalloy (Ni-Cr-Mo) |
| Size | 1/2″ NB to 24″ NB (DN 15 to DN 600); larger to ASME B16.47 |
| Class / Rating | 150#, 300#, 600#, 900#, 1500#, 2500# · 3000#, 6000#, 9000# (socket-weld / threaded) |
| Pressure Ratings | PN 6 – PN 400 (PN6, 10, 16, 25, 40, 64, 100, 160, 250, 320, 400) |
| Material Standards | ASTM B564, ASME SB564, AMS 5837; EN designation 2.4602 |
| Dimensional Standards | ASME B16.5, ASME B16.47 (Series A & B), MSS SP-44, DIN EN 1092-1 |
| Flange Types | Weld Neck (WNRF), Slip-On (SORF), Blind, Socket Weld (SWRF), Lap Joint, Threaded / Screwed, Spectacle Blind, Long Weld Neck, Orifice, Plate |
| Flange Faces | Raised Face (RF), Flat Face (FF), Ring Type Joint (RTJ), Tongue & Groove (T&G) |
| Weld Filler | ERNiCrMo-10 / ENiCrMo-10 (AWS A5.14 / A5.11) |
| Testing | PMI, hydrostatic, UT, MT/PT per spec; EN 10204 3.1 / 3.2 |
The high chromium of C22 (~22%) gives it superior resistance in oxidizing media, while the molybdenum and tungsten protect against localized corrosion in reducing and chloride-bearing conditions. The very low carbon (0.015% max) prevents harmful carbide precipitation in welds.
| Element | Hastelloy C22 (UNS N06022) |
|---|---|
| Nickel (Ni) | Balance (~56%) |
| Chromium (Cr) | 20.0 – 22.5% |
| Molybdenum (Mo) | 12.5 – 14.5% |
| Tungsten (W) | 2.5 – 3.5% |
| Iron (Fe) | 2.0 – 6.0% |
| Cobalt (Co) | 2.5% max |
| Manganese (Mn) | 0.5% max |
| Carbon (C) | 0.015% max |
| Silicon (Si) | 0.08% max |
| Vanadium (V) | 0.35% max |
| Mechanical Property (solution annealed, typical) | Hastelloy C22 |
|---|---|
| Tensile Strength | 690 – 760 MPa (100–110 ksi) |
| Yield Strength 0.2% | 310 – 355 MPa (45–51 ksi) |
| Elongation | 45 – 62% |
| Hardness | ≤ 100 HRB (typ. ~89 HRB) |
| Density | 8.69 g/cm³ |
| Melting Range | 1357 – 1399 °C |
| Standard | Hastelloy C22 Designation |
|---|---|
| UNS (USA) | N06022 |
| Werkstoff (Germany) | 2.4602 |
| EN designation | NiCr21Mo14W |
| ASTM / ASME | B564 / SB564 (forgings); B574, B575, B619, B622 (other forms) |
| AMS | 5837 |
| Common names | Hastelloy C-22, Alloy C22, Alloy 622 |
C22 Weld Neck Flange (WNRF)
C22 Slip-On Flange (SORF)
C22 Blind Flange
| Flange Type | Description & C22-Specific Use |
|---|---|
| Weld Neck (WNRF) | Tapered hub butt-welded to pipe for high-integrity, high-pressure corrosive service; weld with ERNiCrMo-10 filler, no PWHT. |
| Slip-On (SORF) | Fillet-welded over the pipe; common in chemical and FGD piping at moderate pressure. |
| Blind | Seals pipe ends and vessel nozzles in scrubbers, reactors and acid systems. |
| Socket Weld (SWRF) | Small-bore (1/2″–2″) instrument and branch connections in corrosive service. |
| Lap Joint (LJRF) | Used with a C22 stub end where frequent dismantling is required; economizes on alloy in the backing ring. |
| Threaded (TRFF) | Internal NPT/BSP threads for non-welded low-pressure connections. |
| Spectacle Blind / Long Weld Neck | Isolation spades and nozzle/long-neck flanges in C22 for chemical and pollution-control duty. |
| Property | C22 (N06022) | C276 (N10276) | C2000 (N06200) |
|---|---|---|---|
| Chromium | ~22% | ~16% | ~23% |
| Molybdenum | ~13% | ~16% | ~16% |
| Tungsten | ~3% | ~3-4% | — |
| Copper | — | — | ~1.6% |
| Best in oxidizing media | Excellent | Good | Excellent |
| Best in reducing media | Very good | Excellent | Excellent |
| Typical role | Versatile oxidizing / mixed acids | Reducing / chloride workhorse | Both oxidizing & reducing acids |
High Cr + Mo + W make C22 one of the most versatile alloys — equally at home in oxidizing, reducing and fluctuating media.
Outstanding resistance to localized attack and chloride stress-corrosion cracking, even in hot chloride solutions.
Very low carbon and silicon resist HAZ sensitization — usable as-welded without PWHT in most applications.
Excellent in mixed and contaminated acids and rapidly changing process chemistries where other alloys struggle.
| Industry | Typical Application |
|---|---|
| Chemical & Petrochemical | Reactor, column and piping flanges in oxidizing and mixed-acid service |
| Flue-Gas Desulphurization (FGD) | Scrubber, ducting and stack-liner flanged connections in wet/acidic chloride service |
| Pharmaceutical & Agrochemical | Corrosion-critical process and high-purity flanged joints |
| Pulp & Paper | Bleaching plant (chlorine dioxide) piping and equipment flanges |
| Pollution Control & Waste | Scrubbers, pickling lines and waste / acid-recovery flanges |
| Oil & Gas / Sour Service | Acid-gas, sour and chloride-bearing well-stream flanged connections |
Made from certified C22 with PMI verification of Cr, Mo and W — full chemistry confirmed on the MTC.
Manufactured to ASTM B564 / ASME B16.5 in the solution-annealed condition for full corrosion resistance.
WNRF, SORF, blind, socket-weld, threaded, lap-joint, spectacle, LWN, orifice and plate — in RF, FF, RTJ and T&G.
EN 10204 3.1 / 3.2 MTC, heat/lot traceability, hydrostatic and third-party inspection on request.
C22 flange prices reflect the high nickel, chromium and molybdenum content plus forging and machining — it is a premium superalloy for the most corrosive and oxidizing service. Tesco Steel & Engineering offers competitive ex-works pricing from Mumbai with full export documentation and material traceability. Click Ask for Quote or message us on WhatsApp at +91 92233 66922 with flange type, size (NB), pressure class, quantity and documentation requirements.
Q1. What is a Hastelloy C22 flange?
A Hastelloy C22 flange is a pipe flange made from the nickel-chromium-molybdenum superalloy UNS N06022 (W.Nr. 2.4602) — about 56% nickel with ~22% chromium, ~13% molybdenum and ~3% tungsten. C22 is one of the most versatile corrosion-resistant alloys, performing well in both oxidizing and reducing media and resisting pitting, crevice corrosion and chloride stress-corrosion cracking. Flanges are forged to ASTM B564 and machined to ASME B16.5 / B16.47 dimensions in all standard types and classes.
Q2. What is the chemical composition of Hastelloy C22?
Hastelloy C22 (UNS N06022) nominal composition: nickel balance (~56%), chromium 20–22.5%, molybdenum 12.5–14.5%, tungsten 2.5–3.5%, iron 2–6%, cobalt 2.5% max, with very low carbon (0.015% max) and silicon (0.08% max). The high chromium combined with molybdenum and tungsten is what gives C22 its broad resistance across oxidizing and reducing conditions.
Q3. What is the difference between Hastelloy C22 and C276?
Both are Ni-Cr-Mo alloys. C22 (N06022) has higher chromium (~22%) and slightly lower molybdenum (~13%), giving better resistance in strongly oxidizing media, mixed acids and fluctuating oxidizing/reducing conditions, plus excellent resistance to localized corrosion. C276 (N10276) has higher molybdenum and tungsten (~16% Mo, ~3–4% W), giving superior resistance in strongly reducing environments. C22 is often the more versatile all-rounder, while C276 is the long-established choice for reducing/chloride-bearing service.
Q4. What standards apply to Hastelloy C22 flanges?
Hastelloy C22 flanges are forged to ASTM B564 (UNS N06022) and machined to ASME B16.5 (1/2 inch to 24 inch) or ASME B16.47 / MSS SP-44 for larger sizes, with EN 1092-1 for PN-rated flanges. The European designation is W.Nr. 2.4602 / NiCr21Mo14W. Material is supplied with EN 10204 3.1 / 3.2 certification.
Q5. What media is Hastelloy C22 resistant to?
Hastelloy C22 resists oxidizing aqueous media such as ferric and cupric chlorides, wet chlorine, hypochlorite and chlorine dioxide, nitric and mixed nitric/hydrofluoric acids, hot contaminated sulphuric and phosphoric acids, and seawater. It is one of the few alloys able to handle both oxidizing and reducing conditions and rapidly fluctuating chemistries, which is why it is widely used in chemical processing and pollution-control plants.
Q6. Can Hastelloy C22 flanges be welded?
Yes. Hastelloy C22 has excellent weldability by GTAW (TIG), GMAW and SMAW using matching ERNiCrMo-10 / ENiCrMo-10 filler. Because of its low carbon and silicon it generally needs no post-weld heat treatment and can be used in the as-welded condition. Heat input should be controlled and interpass temperature kept low to preserve corrosion resistance.
Q7. What temperature can Hastelloy C22 flanges handle?
Hastelloy C22 retains good strength and corrosion resistance from cryogenic temperatures up to about 1040 degrees C (1900 degrees F) for oxidation resistance, though for wet-corrosion service it is most often used up to around 400–650 degrees C. It also has excellent low-temperature toughness for cryogenic flanged connections.
Q8. What are the mechanical properties of Hastelloy C22?
Typical Hastelloy C22 properties in the solution-annealed condition: tensile strength about 690–760 MPa (100–110 ksi), yield strength about 310–355 MPa (45–51 ksi), elongation about 45–62%, density 8.69 g/cm³. It combines high strength with excellent ductility and toughness.
Q9. What industries use Hastelloy C22 flanges?
Hastelloy C22 flanges are used in chemical and petrochemical processing, flue-gas desulphurization (FGD) and pollution control, pharmaceutical and agrochemical plants, pulp and paper bleaching, pickling and waste-treatment systems, and oil & gas sour/acid-gas service — especially where the media is strongly oxidizing, mixed-acid or rapidly fluctuating.
Q10. Are Hastelloy C22 flanges supplied with material test certificates?
Yes. Every Hastelloy C22 flange is supplied with EN 10204 3.1 (or 3.2) mill test certificates confirming chemistry, mechanical properties and heat/lot traceability, with PMI, hydrostatic testing and third-party inspection on request. Tesco Steel & Engineering is an ISO 9001:2015 certified manufacturer and exporter from Mumbai, India.