utility

Valves for Cooling Water Service

Cooling water — open or closed circuit — is found in almost every industrial plant. Corrosion, scaling, and microbiological fouling are the main concerns. Open circuit cooling towers use treated water with biocides and corrosion inhibitors. Closed-loop systems are typically less corrosive.

Pressure Range

1–16 bar

Temperature

10–50°C (open circuit); up to 90°C (closed loop)

Industries

Power plants, Refineries, Chemical plants

INDICATIVE ONLY — Reference DisclaimerCooling water chemistry (corrosion inhibitors, biocides, pH, hardness) significantly affects material compatibility. Always review with your water treatment specialist and verify biocide compatibility with valve elastomers. Vajra Industrial Solutions accepts no liability for material selection decisions based on this guide.

Key Properties — Cooling Water

  • Open circuit: risk of MIC (microbiological corrosion), scaling, and corrosion
  • Chlorine and biocide addition can affect elastomers
  • Water chemistry (pH, TDS, hardness) determines material requirements
  • Velocity: carbon steel acceptable above 1 m/s to prevent settling
  • Closed loop: inhibitor-treated, lower corrosion risk than open circuit

Material Compatibility — Cooling Water

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/A105)GoodStandard for closed-loop cooling water. Open circuit: corrosion inhibitor program required.
Ductile IronGoodWidely used in cooling water systems — flanged to ASME/EN.
SS 316LExcellentFor high-quality or process-critical cooling water systems.
Cupro-Nickel 90/10GoodGood for saline or brackish cooling water.
EPDM (seat/seal)ExcellentStandard for cooling water butterfly and ball valve seats.
NBRGoodAcceptable — verify compatibility with specific biocide and inhibitor chemicals used.

Recommended Valves

Resilient-seated butterfly valve (EPDM)

Standard for cooling water isolation — PN 10/16, cost-effective for large bore

Carbon steel gate valve (ASME 150)

Mainline isolation on cooling water headers

Y-strainer

Essential before heat exchangers, condensers, and control valves

Dual-plate wafer check valve

Non-return on cooling water pumps — compact, low pressure drop

Valves to Avoid

Unlined cast iron valves in biocide-treated or chlorinated cooling water

Bronze/brass valves where zinc dezincification is a risk (low pH, high flow)

PTFE-seated ball valves where biofouling on ball seat is a risk

Special Considerations

Velocity below 1 m/s in carbon steel — deposits and under-deposit corrosion
Y-strainer mesh sizing: 3mm mesh for cooling tower water, 1mm before instruments
Biofouling: full-bore ball valves allow easier pigging/flushing
Legionella risk in open cooling towers — no dead-legs in cooling water design

Applicable Standards

ASME B16.34AWWA C504 (butterfly)AWWA C509 (gate)EN 1171 (CI gate valves)

Shop Valves for Cooling Water Service

Other Fluid Services

Need Valves for Cooling Water Service?

Tell us your fluid, pressure, and temperature — we'll recommend the right valve, material, and standard.