Article provided by: Harwil Corp.

How To Select The Ideal Float Switch For Your Particular Needs

Some factors need to be adhered to when choosing a float switch for a liquid level sensing application. These factors include cable type, electrical ratings, physical arrangements, float switch and gasket materials.

A lot of industrial processes require implementations that can detect the level of liquid present in various types of chambers or tanks. The indications from these tools may be able to indicate the status or may be used to control the process of production.

A float switch is one of the most well-proven and efficient tools used for detecting the level of liquids in a container. This switch consists of a fixed housing with a magnetic reed switch inside and a magnet provided within a float. As a result of the alternating liquid level, the motion of the float will trigger the reed switch to turn (either open or close) at a specific level. While there are several factors to consider while choosing the perfect float switch for your needs, this piece will discuss some of the most relevant ones.

Physical arrangement and style

The choice of material designs that may be fitting for a particular application will rely on the availability of access to the container, the possible mounting positions and the physical arrangements of the tank. The most common styles are the vertical mounting and the side/horizontal mounting. Vertical mounting typically has a fixed upright stem which slides a cylindrical float and is installed through the bottom or top of a tank while the side/horizontal mounting type is usually a set housing and a hinged float fitted to the fixed house which passes through the sidewall of a container.

Another vital factor that should be taken into consideration is whether there is a likelihood of a buildup deposits from the liquid on the free container. Over a period, these formed deposits can cause failure in the float switches.

Material selection

It is essential to choose a float switch that is designed from the right materials that are ideal for the temperatures and liquids of the particular application. A float switch failure can result from component damage arising from the use of the wrong materials. Use of inappropriate materials uses unwanted consequences.


It is essential to know the electrical ratings of the load that needs to be switched and makes sure that the float switch is compatible with the pack. Entirely resistive loads are the mostly specified by manufacturers in the float switch specifications. A proper protective measure should be applied in any load that has either capacitive or inductive components.


It is paramount to specify materials for the wire used in connecting the float switches, especially if will be applied where spontaneous fluids may spill into the external wiring. For the various float switches and other specialized materials, there are recommended UL-approved cable types.

Custom engineered float switches

The float switch should be chosen based on the operating environment. For instance, a simple plastic float switch may be singly needed for industrial processing water tank. However, an explosion-proof float or stainless steel switch will be required if the area of application is hazardous like a petrochemical storage tank where dust, vapors, and flammable gases are present.


Harwil Corp.

(805) 988-6800

Float Switch

541 Kinetic Dr


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