Float type level switches are devices used to detect the level of liquids in tanks or vessels by utilizing the buoyancy principle. These switches consist of a buoyant float, typically made of a material such as stainless steel, plastic, or foam, attached to a stem or guide rod. The float moves freely with the liquid surface, rising or falling as the liquid level changes.

The float is connected to a switch mechanism, which is activated or deactivated based on the float's position. When the liquid level reaches a predetermined point, the float triggers the switch, signaling the presence or absence of the liquid at that level.

There are two main types of float type level switches:

1. Mechanical Float Switches:

   • Mechanical float switches use a simple mechanical mechanism to detect the position of the float.
   • As the liquid level rises or falls, the float moves a lever arm or rod, actuating a mechanical switch mechanism.
   • These switches are typically used in applications with relatively clean liquids and moderate temperature and pressure conditions.

2. Magnetic Float Switches:

   • Magnetic float switches utilize a magnet contained within the float and a magnetic sensor or reed switch located outside the tank.
   • As the float moves with the liquid level, the magnet within the float triggers the sensor or reed switch, causing it to change state.
   • These switches are often used in applications where direct contact between the sensor and the liquid is undesirable or where the tank walls are non-metallic.

Float type level switches are commonly used in various industries for liquid level control, alarm systems, pump control, and safety shutdown applications. They are relatively simple, reliable, and cost-effective solutions for detecting liquid levels, particularly in applications with stable or slowly changing liquid levels. However, they may not be suitable for use with aggressive or corrosive liquids, and care must be taken to ensure proper selection and installation to prevent issues such as float sticking or mechanical failure.