HomeValve MaterialsASTM B443 / UNS N06625 (Inconel 625)

Valve Material Reference

ASTM B443 / UNS N06625 (Inconel 625) Valve

Inconel 625 / Alloy 625

Inconel 625 (UNS N06625) is a nickel-chromium-molybdenum alloy with outstanding corrosion resistance across a wide range of aggressive environments — seawater, oxidising and reducing acids, chloride solutions, and high-temperature oxidising gases.

Form

Both

Max Temp

+980°C (+1800°F)

Min Temp

−196°C (−321°F)

Category

Nickel Alloy

Chemical Composition — ASTM B443 / UNS N06625 (Inconel 625)

Ni ≥ 58%, Cr 20–23%, Mo 8–10%, Nb+Ta 3.15–4.15%, Fe ≤ 5%, Al ≤ 0.40%, Ti ≤ 0.40%.

Temperature Range

−196°C to +980°C (−321°F to +1800°F)

Maximum Temperature

+980°C (+1800°F)

Minimum Temperature

−196°C (−321°F)

Equivalent Grades — ASTM B443 / UNS N06625 (Inconel 625)

StandardEquivalent Grade
UNSN06625
ASTMB443 (plate), B446 (bar), B564 (forged fittings)
ENNiCr22Mo9Nb / 2.4856

Suitable Services

Seawater and subsea service (HP/HT wells, HPHT risers)

Chloride-rich process streams and acid chloride mixtures

Acid gas (CO₂ + H₂S) injection wells

Flue gas desulphurisation (FGD) — wet scrubber environment

Nuclear primary coolant and waste handling systems

Aerospace and defence high-temperature systems

Not Suitable For

Concentrated hydrofluoric acid (HF) — use Monel 400

Strongly reducing mineral acids at high concentration

Valve Body Applications

Subsea chemical injection valves and manifolds

Offshore riser isolation valves

Acid gas injection valves (CO₂ + H₂S)

High-concentration acid service valves (nitric, phosphoric)

Trim Applications

Ball valve balls and seats — overlaid or solid Inconel 625

Globe valve stem and disc — Alloy 625 bar stock

Gate valve wedge hard-facing — Inconel 625 weld overlay

Typical Valve Types in ASTM B443 / UNS N06625 (Inconel 625)

Ball valves: subsea chemical injection, Class 600–2500

Globe valves: acid service, instrumentation

Gate valves: offshore HP/HT isolation service

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Technical Reference

Industry Applications · 10 min read

How to Specify Industrial Valves for Chemical Service: A Complete Guide

Chemical plants handle some of the most aggressive fluids in any industry — strong acids, chlorinated solvents, caustic solutions, oxidising agents, and toxic gases. Specifying the wrong valve body material, seat, or seal material can lead to catastrophic corrosion, product contamination, or unsafe failure. This guide covers every variable in chemical valve specification.

All Valve Materials

Need ASTM B443 / UNS N06625 (Inconel 625) Valves?

We supply ASTM B443 / UNS N06625 (Inconel 625) (Inconel 625 / Alloy 625) 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.