Flanged external cage type level switches are completely self-contained units designed for side mounting to a tank or vessel with threaded, socket weld or flanged pipe connections. In hundreds of industrial applications throughout the petroleum refining, petrochemical production and power generation markets, these switches have demonstrated their worth through reliable and repeatable service.
A permanent magnet is attached to a pivoted switch actuator. As the float/displacer rises following the liquid level, it raises the attraction sleeve into the field of the magnet, which then snaps against the non-magnetic enclosing tube, actuating the switch. The enclosing tube provides a static pressure boundary between the switch mechanism and the process. On a falling level, the float/displacer deactivates the switch.
- Carbon steel float chambers
- Stainless steel float and trim
- Service pressures up to 900 psig (62 bar)
- Process temperatures to +1000 °F (+540 °C)
- Specific gravity ratings as low as 0.34
- Chamber internals accessible via flange top
- Single or multiple switch mechanisms
- 1", 1½", or 2" tank connections available in either NPT, socket weld, flanged side/side or flanged side/bottom construction
The buoyancy force of a process liquid on the float causes the float to ride on the liquid surface. The movement of the float with the liquid level moves an attraction sleeve into the field of the switch magnet, pulling the magnet toward the sleeve and actuating the switch.