Honeywell L404F Pressuretrol Controller

The Honeywell L404F Pressuretrol® Controller is a mechanical pressure controller (pressure switch) designed to provide operating control with automatic limit protection for pressure systems. It is part of Honeywell’s PressureTrol series and is commonly used in steam boilers, compressed air systems, and other fluid pressure applications where control of pressure and safety limits is required. The controller uses a diaphragm sensing element and a snap-action switch to open or close an electrical circuit when pressure rises to or falls from a setpoint, with an adjustable differential for fine control. The unit includes a clear plastic cover for viewing setpoints, a 1/4″-18 NPT connection for piping, and a grounded terminal for secure installation. The L404F model is suitable for steam, air, noncombustible gases, or non-corrosive fluids up to roughly 300 psi (2070 kPa).