B73 & Series 75
Sealed External Cage
Liquid Level Switches
DESCRIPTION
Sealed external cage type level switches are completely
self-contained units designed for side mounting to a tank
or vessel with threaded or flanged pipe connections.
These units are an industry standard in petroleum
refineries and chemical plants. Thousands of these
switches are in daily service throughout the world.
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
•
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 or
Groups B, C & D polymer coated aluminum
•
1", 1
1
⁄
2
", or 2" tank connections available in either
NPT, socket weld, flanged side/side or flanged
side/bottom construction
•
Optional high temperature insulation available.
See bulletin 41-106.
APPLICATIONS
•
Accumulators
•
Receivers
•
Flare pots
•
Scrubbers
•
Oil refineries
•
Flash tanks
•
Knockout drums
•
Storage tanks
•
Separators
•
Chemical processing plants
•
Steam and electric generating stations
TECHNOLOGY
A permanent magnet
is attached to a pivoted switch
actuator and adjustment screw
. As the float
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, an inconel spring retracts
the magnet, deactivating the switch.
2
5
6
4
1
3
Pivot
Return
Spring
Process Liquid
Process Liquid
Rising Level
Falling Level
MAGNETROL [ MAGNETROL INTERNATIONAL, INC. ]
