Core Features Manual Reset Function: The PD11S1 is a manual reset pressure switch. When the system pressure crosses the activation point, the switch changes its electrical state (cut - in/cut - out) and locks. An operator must press the manual reset button to return the switch to its normal state, which is useful for applications where system inspection is required after a maximum pressure has been exceeded. All - Welded Stainless Steel Construction: It features an all - welded unit design that eliminates leak paths. The stainless steel body makes it suitable for all - weather use and compatible with monitoring cleaning agents and gases. Adjustable Pressure Setpoint: Allows for the adjustment of the pressure setpoint to meet specific system requirements, enabling precise pressure control. Typical Applications Fire Suppression Systems: Used to monitor and control pressure in fire suppression systems, ensuring that the system is ready to operate when needed. HVAC - R Control: Applied in heating, ventilation, air - conditioning, and refrigeration systems for pressure regulation and protection. Food Processing: Suitable for use in food processing plants, where it can monitor pressure in various fluid handling systems while meeting hygiene requirements due to its stainless - steel construction.