HomeService by FluidPhosphoric Acid (H₃PO₄)

corrosiveH₃PO₄CAS 7664-38-2

Valves for Phosphoric Acid (H₃PO₄) Service

Phosphoric acid is a moderate acid used in fertiliser production (wet process phosphoric acid), food processing, metal surface treatment, and semiconductor manufacturing. Wet process P₂O₅ contains fluoride and sulfate impurities that dramatically increase corrosivity over pure acid.

Pressure Range

1–16 bar

Temperature

Ambient to 100°C

Industries

Fertiliser (DAP, MAP, SSP), Food additives (cola, baking powder), Metal surface treatment (pickling)

INDICATIVE ONLY - Reference DisclaimerWet process phosphoric acid with fluoride impurities requires detailed materials selection review. Fluoride attack on PTFE and metals at elevated temperature is not always reflected in generic compatibility tables. Consult a specialist corrosion engineer. Vajra Industrial Solutions accepts no liability for material selection decisions based on this guide.

What valves are used for Phosphoric Acid (H₃PO₄) service?

Hastelloy C-276 ball valve are recommended for Phosphoric Acid (H₃PO₄) service: Wet process phosphoric acid with fluoride/sulfate impurities.

Key Properties - Phosphoric Acid (H₃PO₄)

  • Wet process phosphoric acid contains HF and H₂SO₄ impurities - far more corrosive
  • Pure food-grade phosphoric acid is relatively mild
  • SS 316L acceptable for food-grade and clean phosphoric acid
  • Fluoride content in wet process acid attacks many metals and PTFE at elevated temperature
  • Rubber lining is a primary defence for wet process acid

Vajra Industrial Solutions manufactures and supplies valves for Phosphoric Acid (H₃PO₄) service — including hastelloy c-276 ball valve — in corrosion-appropriate materials selected for the operating conditions described here, with full material and test documentation.

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Material Compatibility - Phosphoric Acid (H₃PO₄)

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

MaterialRatingNotes
Carbon SteelPoorHigh corrosion rate in most phosphoric acid concentrations.
SS 316LGoodFood-grade or pure H₃PO₄ up to 85% at ambient. Not for wet process acid with fluoride.
Hastelloy C-276ExcellentBest choice for wet process phosphoric acid with fluoride impurities.
Rubber-lined (natural rubber)GoodExcellent for wet process acid - industry standard for large bore piping.
FRP / PVDF-linedGoodPVDF good for clean phosphoric acid service.
PTFE-linedGoodExcellent for clean phosphoric acid. Caution with fluoride-bearing wet process acid at elevated temperature.

Recommended Valves

Hastelloy C-276 ball valve

Wet process phosphoric acid with fluoride/sulfate impurities

Full selection guide

Rubber-lined butterfly valve

Large bore wet process acid service - industry standard

Full selection guide

SS 316L ball valve

Food-grade and pure phosphoric acid service

Full selection guide

PTFE-lined diaphragm valve

Clean phosphoric acid in pharmaceutical and food processing

Full selection guide

Valves to Avoid

Carbon steel valves (high corrosion rate)

Copper alloys

Standard SS 304 in concentrated acid

Special Considerations

Wet process acid: always specify full material compatibility review including fluoride content
Food/semiconductor grade: full-bore, electropolished SS 316L, zero dead-legs
Scale and gypsum deposition in wet process systems - ball valves preferred over globe

Applicable Standards

ASME B16.34FDA 21 CFR 178 (food grade)API 607

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Phosphoric Acid (H₃PO₄) Service — Procurement & Specification

Typical Applications

Fertiliser (DAP, MAP, SSP)Food additives (cola, baking powder)Metal surface treatment (pickling)Semiconductor manufacturing

Available Standards

ASME B16.34FDA 21 CFR 178 (food grade)API 607

Material Options

SS 316LHastelloy C-276Rubber-lined (natural rubber)FRP / PVDF-linedPTFE-lined

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

Connected Engineering

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