Series B73 and series 75 sealed external cage liquid level switches
Series B73 and series 75 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. These float-actuated controls have proven their reliability in process control for decades.
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 Features
Carbon steel or stainless steel welded float chamber
Service pressures up to 2240 psig (154 bar)
Process temperatures up to +1000 °F (+538 °C)
Specific gravity ratings as low as 0.32
Available switch styles including dry contact, hermetically sealed and pneumatic
hoice of switch mechanism enclosure: ? TYPE 4X/7/9 Class I, Div. 1, Groups B, C & D, polymer coated aluminum ? NEMA 1, carbon steel for pneumatics
Choice of tank connection: ? 1", 1½" or 2" NPT ? 1", 1½" or 2" flanged side/side ? 1", 1½" or 2" flanged side/bottom ? 1", 1½" or 2" socket welds
Options
Interface calibration
Extreme temperature modifications
Customized installation dimensions
Customized exterior surface preparation and finish
Customized actuation levels
Vent and drain connections
Operating principle
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 Approvals
ATEX
Ex d, Ex ia
CCOE
Ex d
CSA
XP
FM
XP
EAC (GOST)
Ex d, Ex ia
IEC
Ex d, Ex ia
Inmetro
Ex d
Korea
Ex d
NEPSI
Ex d
SIL
SIL 2 (1oo1)
Other approvals are available. Consult factory for more details.