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Flanged external cage liquid level switches

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.

External cage side-bottom side
Technology

External cage switches

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 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

Options

  • Dry contact, hermetically sealed and pneumatic switch mechanisms
  • Choice of switch enclosure
  • Interface level
  • Custom materials of construction available upon request
  • Customized levels and mounting dimensions
  • Vent and drain connections
  • High temperature insulation
  • Extreme temperature modifications

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.

External cage level switch
External cage level switch

Approvals

XP=Explosion Proof, IS=Intrinsically Safe, NI=Non-Incendive, NS=Non-Sparking, ELV=EMC/Low Voltage

ATEX Ex d, Ex ia
CCOE Ex d
CSA XP
FM XP
EAC (GOST) Ex d, Ex ia
IEC Ex d
Inmetro Ex d
Korea Ex d
NEPSI Ex d
SIL SIL 2 (1oo1)

Other approvals are available. Consult factory for more details.

Downloads

Approvals & certificates

ATEX Ex d certificate Mechanicals
ATEX Ex i certificate Mechanicals
Canadian certificate Mechanical Switches - IS, NI
FM certificate Mechanical Switches
FMEDA Report Flanged Sealed Cages
IECEx d certificate Mechanicals

Instruction manuals

Flanged Top External Caged Liquid Level Switches I&O Manual
External cage type level switches are completely self contained units designed for side mounting to a tank or vessel with...

Product catalogs

Flanged Top External Caged Liquid Level Switches
External cage type level switches are completely self contained units designed for side mounting to a tank or vessel with...

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