Float and Board Level Indicators: A Reliable Solution for Tank Level Measurement

In industries where accurate liquid level measurement is crucial—such as oil & gas, water treatment, chemical processing, and power plants—Float and Board Level Indicators continue to be a dependable and cost-effective solution. Known for their simplicity, durability, and non-electronic operation, these mechanical indicators offer a highly visible and maintenance-friendly method to monitor liquid levels in large storage tanks and reservoirs.
What is a Float and Board Level Indicator?
A Float and Board Level Indicator is a mechanical system used to visually monitor the level of a liquid within a storage tank. It operates on the basic principle of buoyancy, where a float (typically made from stainless steel or plastic, depending on the liquid) moves up and down along with the liquid level. This motion is transferred to a scale board or indicator board mounted on the exterior of the tank using a wire rope, pulley system, and a counterweight.
The float inside the tank rises or falls as the liquid level changes, and the corresponding movement is shown on the external board via a pointer or indicator, offering a clear and direct reading.
Key Components
- Float – Typically a hollow cylindrical or spherical object, selected based on liquid type, density, and pressure.
- Scale Board – Graduated scale mounted externally to the tank for direct level reading.
- Wire Rope & Pulley System – Transfers the motion of the float to the indicator.
- Counterweight – Balances the system for smooth and accurate movement.
- Guide Pipe or Bracket (optional) – Helps keep the float steady in turbulent conditions.
Advantages of Float and Board Level Indicators
- No Power Required: Ideal for remote locations where power is unavailable.
- Cost-Effective: Lower initial and maintenance costs compared to electronic systems.
- Highly Visible: Large-scale boards make reading easy from a distance.
- Robust & Long-Lasting: Built to withstand harsh industrial environments.
- Customizable: Can be tailored to tank sizes ranging from a few meters to over 15 meters in height.
Typical Applications
- Underground and Overhead Storage Tanks
- Oil Terminals and Refineries
- Firewater Storage Tanks
- Process Water Reservoirs
- Effluent and Wastewater Plants
Design Considerations
When selecting a float and board level indicator, engineers must consider:
- Tank Height & Diameter
- Fluid Type & Density
- Temperature & Pressure Conditions
- Environmental Exposure (indoor/outdoor/corrosive atmosphere)
Options like SS316, PVC, or PP floats are available based on chemical compatibility. Weatherproof scale boards with UV-resistant markings ensure long life and readability.
Conclusion
While advanced electronic and digital level indicators are on the rise, Float and Board Level Indicators still play a vital role in various industries due to their simplicity, ruggedness, and reliability. For many facilities, especially those in remote or hazardous areas, this tried-and-tested solution remains irreplaceable.
At Japsin Instrumentation, we specialize in designing and manufacturing precision-engineered float and board level indicators tailored to your tank specifications and industry requirements. Get in touch with our team to explore reliable, low-maintenance level monitoring solutions today.
