Liquid Level Indicator – Model 140 LLI

Liquid Level Indicator Model 140 LLI

Model 140 LLI – Liquid Level Indicator

The Model 140-LLI displays the level in a tank by sensing the head pressure on the diaphragm and converting it to movement of a pointer on a fixed scale, continuously indicating liquid level in an atomospheric (vented) vessel.

The Indicator is designed to have a long service with minimal maintenance requirements. Precision machining and calibration provide superior performance and accuracy of measurement while utilizing a set of precision crafted diaphragms as the sensing element, and the superior seal design isolates mechanical working parts from process fluids and corrosive agents in the atmosphere.


Head pressure moves the diaphragm (attached to a shaft) resulting in a linear motion. The shaft connects to the indicator at a pivot point. At this pivot point the linear motion transfers into rotary action, which then moves the indicator to accurately show the liquid level.

Operating Temperature:
-20°F to 225°F.

Maximum Head Pressure:
90 PSI.

Range (Vessel Height):
3 feet through 60 feet.

Electrical Switches:
SPDT Micro Switch; 11 Amp @ 120 to 250 VAC 1/2 Amp @ 125 VDC.

Electrical Connections:
1/2” Female Pipe Thread or 3/4” Female Pipe Thread

Indicator Accuracy:
+ / – 2% of Full Scale

CSA Certified:
Explosion Proof Class I, Division I, Group D


Connector Options:
2” FNPT Standard (Stainless Steel).

Scale Options:
Include feet of water, gallons, barrels and cubic meters and others.

Multipe Switch Options:
Including 2 through 7 switches.

Pulsation Dampener:
The pulsation dampener minimizes pressure spikes caused by erratic flow of liquid into or out of the vessel, delivering a constant pressure on the spring for more accurate readings.

All conections are stainless steel as a standard.

Span and zero adjustment knobs are on the exterior of the unit.

A secondary diaphragm ensures that a leak in the primary diaphragm will not result in a leak to the unit interior.

A leak indicator between the primary and secondary diaphragms lets the operator know if the primary seal is compromised.

Model 140 LLI Back View

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