Cooling Tower Water Float Valve Introduction

A cooling tower water float valve (also called a make-up float valve) is a mechanical level-control valve that automatically maintains the correct water level in the cooling tower basin.

Function of a Cooling Tower Water Float Valve

* Opens when basin water level drops

* Admits makeup water

* Closes when normal operating level is reached

* Prevents pump cavitation, basin dry-out, and overflow

How Cooling Tower Water Float Valve Works (Simple)

1. Water level falls due to evaporation & blowdown

2. Float arm drops

3. Valve opens → fresh water enters

4. Level rises → float lifts

5. Valve closes

No electricity required.

Typical Installation Location Of Cooling Tower Water Float Valve

* Side wall of the cooling tower cold-water basin

* Connected to:

 * City water

 * Softened water

 * RO water

 * Makeup water tank (via pump)

Common Types of Cooling Tower Water Float Valve

 1️⃣ Brass Float Valve

* Most common

* Good for normal water quality

* Economical

 2️⃣ Stainless Steel Float Valve (SS304 / SS316)

* For corrosive or high-TDS water

* Longer service life

3️⃣ Plastic Float Valve (PVC / ABS)

* Lightweight, corrosion-free

* Used in small FRP cooling towers

Typical Sizes & Ratings Of Cooling Tower Water Float Valve

Item	Typical Range
Connection size	¾″ – 2″ (DN20–DN50)
Pressure rating	2 – 6 bar
Flow capacity	5 – 50 m³/h
Temperature	≤ 60 °C

Float Valve vs Electronic Level Valve

Float Valve	Electronic Valve
Mechanical	Sensor-based
Low cost	Higher accuracy
Simple maintenance	Needs power
Small–medium towers	Large / critical systems

Common Problems & Solutions Of Cooling Tower Water Float Valve

Issue	Cause	Solution
Basin overflow	Valve stuck open	Clean / replace valve
Low water level	Float jammed	Adjust or replace float
Water hammer	High pressure	Install PRV
Scaling	Hard water	Improve water treatment

Best Practices

✔ Install strainer upstream

✔ Add isolation valve for maintenance

✔ Set float level above pump suction

✔ Inspect float movement regularly

✔ Use softened or RO makeup water

Typical Cooling Tower Water Float Valve Setting

* Normal operating level: 50–75 mm above pump suction

* Overflow level: below basin overflow weir