Mobrey Magnetic Rod

The Mobrey magnetic rod assembly is the mechanical heart of a Mobrey-style boiler water level control. A permanent magnet is fitted to a float or displacer on a vertical rod that slides inside a non-magnetic stainless-steel pressure tube/centre tube . As the water level changes the float (or displacer) and its attached magnet move, transmitting motion through the tube to one or more externally mounted Mobrey switch units. The switch units contain a unique three-magnet snap-action mechanism (primary/secondary/tertiary magnet arrangement) which gives positive, vibration-resistant latching and reliable switching without springs or mercury. This glandless, hermetically-sealed design makes the assembly particularly suited to the demanding environment of steam boilers — high pressure, high temperature and vibration — while minimising maintenance and eliminating leakage/contamination paths. Pressure & temperature capability: Designed for boiler/process use — many models operate at high pressures and temperatures (example ratings shown in manufacturer data sheets: e.g., certain displacer models up to ~102 bar and temperature ranges up to +300 °C depending on model and options). Always select the model rated for your exact service conditions. Positive, repeatable level detection that tolerates vibration and steam environment. Low maintenance due to sealed magnetic coupling (no dynamic seals/glands on the rod). Safe for hazardous atmospheres with certified flameproof/intrinsically-safe options. D