corrosiveNaOHCAS 1310-73-2
Valves for Caustic Soda (NaOH) Service
Sodium hydroxide (caustic soda) is used extensively in the chlor-alkali industry, paper & pulp, alumina refining, and chemical manufacturing. Concentrated NaOH attacks aluminium and zinc. Hot caustic above 60°C attacks SS 304/316 via stress corrosion cracking (caustic SCC).
Pressure Range
1–25 bar
Temperature
Ambient to 130°C
Industries
Chlor-alkali production, Paper & pulp (kraft pulping), Alumina refining (Bayer process)
What valves are used for Caustic Soda (NaOH) service?
Nickel 200 globe valve are recommended for Caustic Soda (NaOH) service: Hot concentrated NaOH - gold standard material, no SCC risk.
Key Properties - Caustic Soda (NaOH)
- Strong alkali - highly corrosive to aluminium, zinc, and tin
- Caustic SCC: SS 304/316 susceptible above 60°C
- Carbon steel generally acceptable at concentrations up to 50% at ambient temperature
- Exothermic dissolution - generates heat on dilution
- Solidifies below ~12°C at 50% concentration - freeze protection required
Vajra Industrial Solutions manufactures and supplies valves for Caustic Soda (NaOH) service — including nickel 200 globe valve — in corrosion-appropriate materials selected for the operating conditions described here, with full material and test documentation.
Need valves for Caustic Soda (NaOH) service?
Send your fluid conditions — we'll recommend the right valve, material and standard, with a 24-hour quote.
Material Compatibility - Caustic Soda (NaOH)
Ratings are indicative. Actual compatibility depends on concentration, temperature, velocity, and presence of contaminants. Always consult corrosion tables or a materials engineer.
| Material | Rating | Notes |
|---|---|---|
| Carbon Steel (WCB/A105) | Good | Acceptable up to 50% NaOH at ambient temperature. Not for hot concentrated caustic. |
| SS 316L | Fair | Risk of caustic SCC above 60°C. Cold dilute service only - verify. |
| Nickel 200/201 | Excellent | Best all-round material for hot concentrated NaOH. Industry standard. |
| Monel 400 | Good | Good for hot caustic service - preferred where Nickel 200 is cost-prohibitive. |
| PTFE-lined | Excellent | Chemically inert to all NaOH concentrations. |
| Rubber-lined (natural rubber/EPDM) | Good | Good up to 50% at ambient temperature. |
| Aluminium alloys | Not Recommended | Rapidly attacked at all concentrations. |
Recommended Valves
Nickel 200 globe valve
Hot concentrated NaOH - gold standard material, no SCC risk
Full selection guideValves to Avoid
Aluminium-bodied valves (any concentration)
Zinc die-cast components
SS 304/316 in hot caustic above 60°C
Bronze or brass valves
Special Considerations
Applicable Standards
Shop Valves for Caustic Soda (NaOH) Service
Other Fluid Services
Caustic Soda (NaOH) Service — Procurement & Specification
Typical Applications
Available Standards
Material Options
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
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
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
Connected Engineering
Need Valves for Caustic Soda (NaOH) Service?
Tell us your fluid, pressure, and temperature — we'll recommend the right valve, material, and standard, with a 24-hour quote.