Tuffy®II Side-Mounted Float Switch

The Tuffy® II Buoyancy Level Switches are float-actuated devices designed for horizontal mounting in a tank or vessel through threaded or flanged pipe connections. The compact size allows for installation in small vessels, while its many features provide a variety of application uses. The single switch mechanism is available in SPDT or DPDT forms on units designed for fixed or adjustable, narrow or wide differential and interface service levels.

Operating Principle

The TUFFY II achieves switching action through the use of repelling magnets on the float assembly and the switch mechanism. Separating the two magnets is a nonmagnetic pressure barrier.
The float follows the liquid level as it changes, causing the attached float magnet to move into the field of the switch magnet. The like poles of these magnets repel each other causing the switch magnet to change position, actuating the switch.


Day tanks
Fuel storage tanks
Flash tanks
Condesnate reeivers
Cooling towers
High and high/high alarm from single tank entry


Single electric switch for high or low level alarm or control functions
Spacious switch wiring compartment
Pressure ratings to 2160 psig (149 bar)
Process temperatures to +750° F (+399° C)
NACE and/or ASME B31.3 construction
Specific gravity as low as 0.40


Narrow or adjustable level differential
Silver or gold switch contacts
SPDT or DPDT dry contact or hermetically-sealed switches
External mounting chambers
Hastelloy C wetted parts


XP=Explosion Proof (FM, CSA)
IS=Intrinsically Safe (ATEX)
ELV=EMC/Low Voltage (CE)


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