Technology of External cage type level switches
A permanent magnet➀ is attached to a pivoted switch actuator and adjustment screw ➁. As the float ➂ rises following the liquid level, it raises the attraction sleeve ➃ into the field of the magnet, which then snaps against the non-magnetic enclosing tube ➄, actuating the switch ≈. The enclosing tube provides a static pressure boundary between the switch mechanism and the process. On a falling level, an Inconel ® spring retracts the magnet, deactivating the switch.
Features of External cage type level switches
- Carbon steel float chamber.
- Easy inspection of float chamber through removable head.
- Stainless steel float and trim.
- Service pressures up to 900 psig (62 bar).
- Process temperatures up to +1000 °F (+538 °C).
- Specific gravity ratings as low as 0.40.
- Available switch styles including dry contact,hermetically sealed and pneumatic.
- Single or multiple switch mechanisms available.
- Available switch enclosures include : NEMA 1 carbon steel for pneumatics,TYPE 4X/7/9 Class I, Div. 1 Groups C & D aluminum
TYPE 4X/7/9, Class I, Div. 1, Group B, aluminum 1″, 11⁄2″, or 2″ tank connections available in either NPT, socket weld, flanged side/side or flanged side/bottom construction.
- Optional high temperature insulation available.
Applications of External cage type level switches
- Flash tanks
- Knockout drums
- Flare pots
- Storage tanks