The material of construction (MOC) for a closed-circuit cooling tower (CCT) depends on factors like durability, corrosion resistance, environmental conditions, and budget. Below is a detailed breakdown of materials used for key components:
1. Casing/Structure (Frame & Enclosure)
a) Galvanized Steel (Most Common)
- Advantages:
- Cost-effective, strong, and widely available.
Hot-dip galvanized coating resists rust
- Disadvantages:
- Can corrode in coastal or highly acidic environments.
- Use Case:
- Standard industrial applications (HVAC, power plants).
b) Stainless Steel (SS 304 / SS 316)
- Advantages:
- Excellent corrosion resistance (SS 316 better for saltwater).
- Long lifespan with minimal maintenance.
- Disadvantages:
- Expensive (2–3x galvanized steel).
- Use Case:
- Coastal areas, chemical plants, food/pharma industries.
c) Fiberglass-Reinforced Plastic (FRP)
- Advantages:
- Lightweight, rust-proof, and chemically inert.
- Ideal for corrosive or humid environments.
- Disadvantages:
- Less structural strength than metal.
- Use Case:
- Marine, wastewater treatment, aggressive atmospheres.
2. Heat Exchanger Coil (Primary Cooling Coil)
- Copper → Best thermal efficiency (HVAC, general industry).
- Stainless Steel (SS 304/316) → Corrosion-resistant (chemical plants, coastal).
- Titanium → Extreme corrosion resistance (seawater, acidic environments).
- Cupronickel (90/10 or 70/30) → Marine applications (saltwater resistance).
- Carbon Steel (Epoxy-Coated) → Budget option (requires maintenance).
3. Fan Blades & Housing
a) Aluminum (Most Common)
- Lightweight, corrosion-resistant, and cost-effective.
b) Fiberglass (FRP)
- Used in corrosive environments (chemical plants).
c) Stainless Steel
- High-end applications where durability is critical.
4. Water Basin (Sump)
a) Polypropylene (PP) or HDPE (Plastic)
- Advantages:
- Rust-proof, chemical-resistant, and easy to clean.
- Disadvantages:
- Less durable than metal in extreme temps.
b) Stainless Steel (SS 304/316)
- Used in food/pharma or high-corrosion environments.
c) Coated Carbon Steel
- Budget option but requires maintenance.
5. Spray Nozzles & Piping
- PVC/CPVC → Low-cost, corrosion-resistant.
- Stainless Steel → High-pressure or chemical-laden water.
- Brass → Balanced cost and durability.
6. Drift Eliminators & Fill Media
- PVC → Lightweight, chemical-resistant.
- Stainless Steel → High-end applications.
7. Key Factors Influencing Material Selection
- Environment
- Coastal → Stainless steel, FRP, or titanium.
- Industrial → Galvanized steel or coated carbon steel.
- Water Chemistry
- High chlorides → SS 316 or titanium.
- Freshwater → Copper or galvanized steel.
- Budget
- Low-cost → Galvanized steel + epoxy-coated coils.
- High-end → Stainless steel/titanium.
Typical Material Combinations by Industry
| Industry | Casing | Coil Material | Basin |
| HVAC/Data Centres | Galvanized Steel | Copper | Polypropylene |
| Oil & Gas | SS 316 | SS 316/Titanium | SS 316 |
| Marine/Desal | FRP/SS 316 | Cupronickel/Ti | FRP/SS 316 |
| Food & Pharma | SS 304/316 | SS 316 | SS 304/316 |
- Galvanized steel + copper coils → Best for general industrial use.
- Stainless steel (SS 316) + titanium coils → Ideal for harsh environments.
- FRP + cupronickel → Preferred for marine/coastal applications.