Float Switch

A float switch is a reliable liquid level control device that triggers switch signals as the liquid level rises or falls, enabling automatic pump control and level alarms. Resistant to high temperature, pressure, and corrosive media, float switches are widely used in water treatment, chemical, petroleum, food processing, and industrial liquid level monitoring applications.

How Does a Float Switch Work?

A float switch works by using a floating element that rises or falls with the liquid level. When the liquid reaches a preset position, the internal reed switch or microswitch changes state to trigger actions such as starting or stopping pumps, activating alarms, or controlling valves. Float level switches provide simple, stable, and automatic liquid level monitoring without complex electronic systems.

Main Features of Float Switches

• Mechanical Actuation: Float switches do not require external power for sensing. They operate entirely through buoyancy, where the float moves with liquid level changes to achieve natural mechanical triggering.
• Simple Structure, High Reliability: With no complex electronic circuitry, a float switch typically consists of a float, a pivot mechanism, and an internal switch (such as a reed switch). This minimalist design ensures strong resistance to dirt, corrosion, and electrical interference, resulting in very low failure rates compared to electronic sensors.
• Wide Media Compatibility: Float switches can be used with water, oil, chemicals, wastewater, and other liquids, with corrosion-resistant and high-temperature resistant models available for harsh environments.

Common Types of Float Switches

• Cable Float Switch: Cable-suspended, freely floats with liquid level for flexible installation. Widely used in tanks, water reservoirs, and sewage pits.
• Magnetic Float Switch: Uses a built-in magnet inside the float to trigger a reed switch without direct contact. It offers stable operation, low wear, and long service life with high reliability.
• Stainless Steel Float Switch: Made from corrosion-resistant stainless steel for harsh environments. High temperature resistance, strong durability, suitable for chemical, petroleum, and industrial applications.
• Top-Mounted Float Switch: Vertically installed from top, provides excellent sealing. Suitable for closed tanks and pressure vessels.
• Side-Mounted Float Switch: Horizontally mounted on side wall, does not occupy vertical space inside tank. Commonly used for level detection in tanks and equipment sidewalls.
• Multi-point Float Switch: Equipped with multiple floats to detect different liquid levels such as low, medium, and high. It enables multi-level control, automation integration, and improved system safety.

Common Applications of Float Switches

• Industrial Systems: Used in various industrial liquid storage and process control environments to monitor and manage fluid levels safely and reliably.
• Water Management Systems: Applied in water supply, drainage, and wastewater systems to support automatic liquid level control and overflow protection.
• Energy & Infrastructure: Utilized in fuel storage, HVAC, and utility systems to maintain stable operation and prevent liquid-related failures.
• Agriculture & Environmental Systems: Used in irrigation, aquaculture, and environmental water management for automated water level regulation.
• Commercial & Domestic Applications: Found in buildings, equipment, and household systems for basic liquid level monitoring and pump control.

ATO offer a wide range of float switches designed for accurate and reliable liquid level control in various applications. Our product line includes both plastic float switches and stainless steel float switches, providing flexible options for different media and working environments. Whether for water treatment, industrial automation, or liquid storage applications, ATO float switches deliver stable performance, easy installation, and dependable protection against overflow and dry running.