HomeService by FluidCaustic Potash (KOH - Potassium Hydroxide)

corrosiveKOHCAS 1310-58-3

Valves for Caustic Potash (KOH - Potassium Hydroxide) Service

Potassium hydroxide (caustic potash, KOH) is a strong alkaline chemical used in potassium soap production, fertilisers, batteries (alkaline and nickel metal hydride), electrolysers for green hydrogen production, and as a pH adjuster. It is handled in concentrations of 10–50% aqueous solution and is highly corrosive to skin and eyes. Unlike caustic soda (NaOH), KOH is slightly more corrosive to stainless steel at elevated concentration, but both behave similarly from a valve selection standpoint.

Pressure Range

1–20 barg

Temperature

Ambient to +120°C

Industries

Green hydrogen electrolysers, Potassium soap production, Fertiliser plants

INDICATIVE ONLY - Reference DisclaimerCaustic potash is severely corrosive to skin and eyes. PPE (face shield, gloves, apron) mandatory. Hot concentrated KOH causes stress corrosion cracking in carbon steel - verify material qualification with process engineer. Vajra Industrial Solutions accepts no liability for material selection decisions based on this guide.

What valves are used for Caustic Potash (KOH - Potassium Hydroxide) service?

Ball Valve (SS 316L or PTFE-lined) are recommended for Caustic Potash (KOH - Potassium Hydroxide) service: Standard isolation for KOH dilution and distribution pipelines.

Key Properties - Caustic Potash (KOH - Potassium Hydroxide)

  • Strong alkali - pH >13 in solution; severely corrosive to skin and eyes
  • Concentrated KOH attacks zinc, aluminium, and tin, and is aggressive to SS at high temp
  • Compatible with carbon steel, SS 316L, Hastelloy, PTFE, PVDF
  • Deliquescent solid - absorbs moisture from air; aqueous solutions are most common
  • Heated KOH (>80°C) is more corrosive - stress corrosion cracking risk for carbon steel

Vajra Industrial Solutions manufactures and supplies valves for Caustic Potash (KOH - Potassium Hydroxide) service — including ball valve (ss 316l or ptfe-lined) — in corrosion-appropriate materials selected for the operating conditions described here, with full material and test documentation.

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Material Compatibility - Caustic Potash (KOH - Potassium Hydroxide)

Ratings are indicative. Actual compatibility depends on concentration, temperature, velocity, and presence of contaminants. Always consult corrosion tables or a materials engineer.

MaterialRatingNotes
Carbon Steel (WCB)GoodAcceptable for KOH <50% up to 80°C. SCC risk above 80°C for stressed CS.
SS 316LGoodGood for dilute KOH; some SCC risk with concentrated hot KOH.
Hastelloy C-276ExcellentExcellent across all KOH concentrations and temperatures.
PTFE-lined / PVDF-linedExcellentBest for concentrated KOH - no metal contact.
Nickel 200ExcellentNickel 200 is excellent for hot, concentrated KOH.
AluminiumNot RecommendedRapidly dissolved by KOH.

Recommended Valves

Ball Valve (SS 316L or PTFE-lined)

Standard isolation for KOH dilution and distribution pipelines

Full selection guide

PTFE-lined Butterfly Valve

Large-bore KOH service - cost-effective corrosion protection

Full selection guide

Globe Valve (SS 316L, Hastelloy trim)

Throttling and control of KOH flow in electrolyser and soap plants

Full selection guide

Diaphragm Valve (PTFE diaphragm)

Accurate KOH dosing control - no metal-fluid contact, zero leak path

Full selection guide

Valves to Avoid

Aluminium or zinc-lined valves

Unlined carbon steel for hot concentrated KOH

Special Considerations

Hot concentrated KOH (>50%, >80°C) causes stress corrosion cracking of carbon steel welds - PWHT required
PTFE-lined or Hastelloy valves preferred above 80°C and >35% concentration
Dilute KOH at ambient temperature: SS 316L acceptable and most economical
Green hydrogen electrolysers: KOH electrolyte at 25–35%, 80–90°C - SS 316L or Ni 200 valves

Applicable Standards

ASME B16.34ISO 9001:2015PED 2014/68/EU

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Caustic Potash (KOH - Potassium Hydroxide) Service — Procurement & Specification

Typical Applications

Green hydrogen electrolysersPotassium soap productionFertiliser plantsBattery manufacturingChemical synthesispH control

Available Standards

ASME B16.34ISO 9001:2015PED 2014/68/EU

Material Options

Carbon Steel (WCB)SS 316LHastelloy C-276PTFE-lined / PVDF-linedNickel 200

Documentation Available

  • -EN 10204 3.1 Material Test Certificates (heat traceable)
  • -API 598 hydrostatic shell & seat test reports
  • -Dimensional inspection reports
  • -Full Manufacturing Data Record (MDR) / data book on request
View documentation package

Inspection Options

  • -In-house QC inspection on every order
  • -Third-party inspection (SGS / Bureau Veritas / TÜV / DNV) coordination
  • -Witness and hold points accommodated on request
View inspection & testing

Order Quantities

Flexible — from single critical-spare valves to full project lots.

Export

Worldwide export with complete documentation (COO, EUR.1, packing lists) to 20+ countries.

Custom Engineering

Built to your specification — materials, trim, pressure class and special service (NACE, fire-safe, IBR, cryogenic).

Delivery Support

Dispatch from Vadodara, Gujarat with documented lead times and priority handling for urgent requirements.

Engineering references

Reviewed by Process Engineering, Vajra Industrial SolutionsDiscipline: Process & Fluid Service EngineeringLast reviewed: 20 June 2026

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