The Model KPFS uses a float to determine the presence or absence of liquid in a vessel at the process connection. The float arm assembly consists of a float at one end and a magnet at the other. As the liquid level in the vessel rises, the float rises, and the magnet falls. The magnet actuates a second magnet on the other side of the pressure boundary. This second magnet is the reactive component in the snap acting switch that opens and closes the pneumatic valve. Because of the nature of the design, adjustment is rarely, if ever needed. In the event that adjustment is needed, an easy to use adjustment screw is provided. The model KPFS is used to actuate pneumatic dump valves, such as the Kenco Model KDV series dump valve to control liquids in separators, scrubbers, etc.
The pressure boundary contains no seals; it is a solid stainless steel barrier that passes a magnetic field, but no liquids. It is impossible for the process liquid to enter the switch enclosure through this barrier.
The Model KPFS Pneumatic Float Switch can be ordered to have the pneumatic valve open when it senses a liquid level rising (-LR option) or open when it senses the liquid level falling (-LF option). A manual operator is provided to open the valve manually if desired.
