When you look at the variety of float switches that are out there, you see that there are a lot of different design options. Float switches can be used for a wide range of different applications, and they can work in many different environments.
In many industrial settings, float switches may need to operate in hazardous locations and/or liquids. For these applications, you would need a switch that is designed to withstand the harsh conditions. When hazardous materials are involved, getting the wrong type of float switch could lead to a disastrous failure.
So what is the difference between a float switch that is suitable for hazardous areas and one that is not? The answer is not as simple as pointing to one type of switch and saying that it is good for working in a hazardous environment. You have to consider different factors that relate to the conditions under which the float switch will be placed.
The properties of the location or liquid in question will be one of the most important factors to consider. What makes this area hazardous? You have to consider how the liquid in the tank is going to interact with the material of the switch. If you are talking about a corrosive substance, then you will need a switch that can resist corrosion.
You also have to consider whether the material is volatile in some way. If you have a material that is flammable or combustible, you might need to get a switch that can stand up to those conditions. In an environment with flammable or combustible materials, you would need a switch that can work safely while eliminating the possibility of ignition. For these situations, something like a stainless steel explosion-proof switch might be necessary.
It may also be important to consider the possibility of a spill. If there is a chance that an aggressive liquid could spill from the tank and damage external wiring, then it might be necessary to use a switch where the wiring has a protective coating or sheath.
A good example of a float switch for hazardous locations and/or liquids is one made of polyphenylene sulfide. It is an engineering plastic that is used for a wide range of purposes. In float switches, it can be particularly beneficial for hazardous liquids because it can withstand extreme heat and various forms of chemical damage. It is resistant to acids, alkali and bleaches, and it is also very durable.
Getting the right switch is always important, but not every application is going to require a float switch that can be resistant to harsh chemicals or one that can withstand an explosion. In many industrial settings, you might just need a simple plastic float switch for a water tank that does not contain corrosive materials or high temperature liquid. In some cases, there may also be the need for a custom-engineered switch for a very specific type of application.