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8600 Series

Senior Spiral Magnetic Liquid-Level Gauges with 1-1/2" MNPT Thread


The 8600 Series Senior spiral gauges are designed for use in measuring liquid levels in hydraulic, lubricating or fuel-oil storage tanks, and gasoline and diesel fuel levels in stationary, standby and mobile generators. The 8600 Series is not recommended for off-road equipment.

General Information & Features

The 8640 spiral gauge incorporates a strong nickel-plated Neo magnet capable of driving a TwinSite® sender which provides a direct, fractional reading and also sends an electrical signal to a remote receiver.

The 8660 spiral gauge is supplied with an easy to read, side-view fractional dial. The model 8680 spiral gauge is equipped with a standard top reading fractional dial.

All 8600 Series spiral gauges have a 1 1⁄2" MNPT tank connection and are suitable for tank pressures up to 25 psig maximum. They are designed for top mounting in tanks up to 36" deep and some models are UL listed for flammable liquids.


Data Sheet

MS-516 Installation Instructions for Spiral Gauges

General Specifications*


Designed for top-mounting only.


Accuracy depends upon proper gauge sizing. Direct read dials +/-8%, TwinSite dials +/-12%. Accuracy may be less depending upon tank shape. Accuracy may be less near full and empty. Accuracy may be less if tank is not level. Device does not prevent overfill. All accuracy estimates are expressed as a percent of full scale.


Standard operating range is -40°F to 158°F, -40°C to 70°C.


Exposed portions should be painted for marine applications, less dial.


Shorter styles are suitable for some mobile, off-road applications.


Shorter styles are suitable for some mobile, off-road applications.


0.5 watts maximum for TwinSite® versions.

Tank Pressure

0 to 25 PSIG [0 - 1,7 Bar] maximum.


Direct indicating gauge. Available UL listed for flammable liquids. Some models UL recognized for marine service.


When Ordering Specify:

1. Gauge model number.

2. Tank height.

3. Ohm range on TwinSite® version.

4. Riser height, if any.

5. Any special requirements.

Materials of Construction*


Die-cast zinc.

Guide Rod

Zinc-plated steel.



Tie Plate, Guide, & Bearing Pin

Stainless steel.

Center Shaft Holder & Magnet Bushing



Nitrile rubber.

Drive Magnet

Neo, nickel-plated.

Standard Dial

Polycarbonate, hermetically sealed.

Side-View Dial

Aluminum with polycarbonate crystal, hermetically sealed.

TwinSite® Sender



Model Number Sender or Dial Type
8640 Senior TwinSite® Sender in choice of
0-30, 0-90, or 240-30 Ohm ranges. Specify your preference when ordering.
8660 #5025S00570
Senior side-reading fractional dial.
8680 #5844S01793
Senior direct-reading fractional dial.


*Materials and specifications are subject to change without notice. Pressure ratings subject to change due to temperature and other environmental considerations.