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Valve Material Reference

ASTM A494 CW6MC / CW12MW Valve

Hastelloy C-276 / Inconel 625 Cast

ASTM A494 CW6MC and CW12MW are cast nickel alloy grades corresponding to Alloy 625 (CW6MC) and Hastelloy C (CW12MW) compositions respectively.

Form

Cast

Max Temp

+1040°C (C-type); +540°C continuous for valve service

Min Temp

−196°C (cryogenic capable)

Category

Nickel Alloy

Chemical Composition — ASTM A494 CW6MC / CW12MW

CW6MC: Ni ≥ 58%, Cr 20–23%, Mo 8–10%, Nb+Ta 3.15–4.15%. CW12MW (C-type): Ni ≥ 54%, Cr 15.5–17.5%, Mo 16–18%, W 3.75–5.25%.

Temperature Range

−196°C to +540°C (Alloy 625); −50°C to +1040°C (Hastelloy C276)

Maximum Temperature

+1040°C (C-type); +540°C continuous for valve service

Minimum Temperature

−196°C (cryogenic capable)

Equivalent Grades — ASTM A494 CW6MC / CW12MW

StandardEquivalent Grade
CW6MC / Alloy 625UNS N06625, ASTM B564 N06625 (forged)
CW12MW / Hastelloy CUNS N10276, ASTM B574 / B564 N10276
EN2.4856 (Alloy 625), 2.4819 (Hastelloy C-276)

Suitable Services

Sulphuric acid (all concentrations and temperatures)

Hydrochloric acid (all concentrations)

Hydrofluoric acid (with care)

Phosphoric acid and phosphate chemicals

Chlorine and wet chlorine gas

Bleaching chemicals (ClO₂, NaOCl)

Seawater (aggressive conditions — splash zone, high velocity)

Mixed acids

Reducing and oxidising environments simultaneously

Not Suitable For

Cost-sensitive applications where SS 316 or duplex will suffice

High-temperature above alloy limits

Very high temperature oxidising gas service (use Inconel 600/800)

Valve Body Applications

Valve bodies for concentrated sulphuric and hydrochloric acid

Hydrofluoric acid (HF) valve bodies

Chlorine and hypochlorite valve bodies

Seawater and high-chloride service

Bleaching chemical valve bodies (pulp and paper)

Trim Applications

Alloy 625 / Hastelloy trim for corrosive service

Ball valve balls and stems in Alloy 625

Typical Valve Types in ASTM A494 CW6MC / CW12MW

Gate, globe, ball, check valves: Class 150–900

Specialist lined or solid Hastelloy valves for HF acid

Exotic alloy diaphragm valves for pharma/chemical

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We supply ASTM A494 CW6MC / CW12MW (Hastelloy C-276 / Inconel 625 Cast) gate valves, globe valves, ball valves, check valves, and more. Full certification documentation — EN 10204 3.1/3.2 MTCs, hydro test certs — as standard.