A ball float valve is a mechanical valve used to automatically control the level of liquid in a tank or vessel. It operates based on the buoyancy of a float (usually a hollow ball) that rises and falls with the liquid level. When the liquid reaches a certain height, the float moves and actuates the valve to either shut off or allow flow — commonly used in water tanks, cooling towers, and cisterns.
How It Works:
- A hollow ball float is attached to a lever arm, which connects to the valve mechanism.
- As the liquid level rises, the float rises with it.
- Once a set level is reached, the float moves the lever, closing the valve to stop inflow.
- When the liquid level drops, the float lowers, causing the valve to reopen and refill the tank.
Main Components:
- Float ball (metal or plastic)
- Lever arm (connects float to valve)
- Valve body (brass, stainless steel, plastic, etc.)
- Inlet port (connected to water/gas line)
- Seat and seal (controls flow closure)
Advantages:
- Simple, reliable, and self-operating
- Requires no external power or electronics
- Cost-effective
- Ideal for open or vented tanks
Limitations:
- Not suitable for high-pressure or high-flow systems
- May wear over time if exposed to dirty or corrosive fluids
- Needs clear space inside the tank for float movement
Common Applications:
- Domestic and industrial water storage tanks
- Cooling towers
- Livestock watering troughs
- Boiler feed systems (in low-pressure settings)
- Rainwater harvesting systems