The FSHPLC is a flow switch designed for connection to a PLC to control external equipment or processes based on flow rate detection. It features a spring-loaded paddle mechanism with a magnetic switch that activates when flow exceeds 20 l/min, and automatically shuts down when flow drops below this threshold. The device is constructed with a brass screw mount and polyamide enclosure rated IP54, with a maximum operating pressure of 10 bar and maximum temperature of 100°C. It provides a volt-free SPNO contact output rated for 1 mA at 5 Vac, connected via 1" BSP pipe connections. The FSHPLC is commonly used to control circulating or centrifugal pumps in water systems with storage tanks, providing automatic flow-based switching for improved system efficiency and reliability.