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Varec 7660

Tactical Collapsible-Tank Fuel Gauge

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Varec 7660

The Varec® 7660 Tactical Fuel Gauge (TFG) is designed for fuel supply officers, petroleum operations specialists, logistics commanders, and military engineers who need automated inventory measurement on collapsible storage tanks at forward operating bases, expeditionary fuel points, disaster-response depots, and remote industrial sites.

Unlike conventional tank gauges engineered for rigid fixed tanks, the 7660 TFG is purpose-built for the flexible, unpredictable geometry of collapsible bladder tanks. It installs in minutes as a direct vent-pipe replacement and operates across arctic-to-desert temperatures from −4 °F to +140 °F (−20 °C to +60 °C).

A single sensor captures both hydrostatic pressure (for level calculation) and temperature via an integrated Pt 100 resistance thermometer per DIN EN 60751, with 4–20 mA (HART) output. Up to four 7660 TFGs daisy-chain to a single 8240 Tactical Data Unit, simplifying cable runs on multi-tank fuel points.

Hazardous-area approvals include ISA/CSA Class 1 Division 2 Groups C and D and ATEX/IECEx Ex II 3(1)G Ex nA [ia Ga] IIB T5 Gc. The sensor is rated IP 68 at 30 bar for full fuel immersion, and the 7660 feeds FuelsManager® through the 8240 TDU and the TacFuels® computing device.

Varec 7660
Varec 7660
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Features

Direct Vent-Pipe Replacement

Installs into the existing CST vent-pipe opening with no drilling, cutting, or tank modification, reducing setup time and minimizing operator error.

Military-Grade Quick Disconnects

MIL-C-5015 bayonet quick disconnects on all power and communication cables enable fast, tool-free deployment and redeployment in field conditions.

Dual Pressure and Temperature Sensing

One sensor captures both hydrostatic pressure (for level calculation) and temperature via an integrated Pt 100 resistance thermometer, removing the need for separate instruments.

Hazardous-Area Certified

ISA/CSA Class 1 Division 2 Groups C/D plus ATEX/IECEx Ex II 3(1)G Ex nA [ia Ga] IIB T5 Gc approvals cover global deployments.

Daisy-Chain Network Architecture

Up to four 7660 TFGs connect in series to one 8240 TDU, reducing cable runs, infrastructure cost, and configuration complexity across multi-tank fuel points.

IP 68 Immersion Protection

The sensor element is rated IP 68 at 30 bar, protecting internal components during full fuel immersion for sensors resting on collapsible tank floors.

Applications

  • Forward Operating Base Fuel Points: Manual tracking creates accountability gaps; the 7660 TFG delivers verified inventory data to command without adding personnel to the fuel point.
  • Expeditionary Aviation Fuel Farms: JIG and FAA practice calls for accurate quantities at every transfer point; continuous TFG measurement supports that at remote airstrips.
  • Disaster Relief Fuel Depots: Temporary fuel infrastructure needs rapid setup; vent-pipe replacement installs a full gauging system in minutes with no tools.
  • Remote Oil & Gas Sites: Unmanned locations rely on autonomous data collection; daisy-chained TFGs supply tank inventory without operator presence.
  • Military Logistics Hubs: DoD accountability programs call for auditable records; HART data feeds FuelsManager® for timestamped custody-transfer documentation.
  • Temporary Mining Operations: Collapsible tanks enable fuel storage where permanent tanks aren't practical; TFGs provide reliable measurement without modifying the site.
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Specifications

Parameter

Specification

Data Transmission Protocol

4–20 mA (HART)

Environmental Operating Temp.

−4 °F to +140 °F (−20 °C to +60 °C)

Power Required

8–36 VDC

Power Consumption

4 mA

Pressure Measurement Ranges

1.45 psig (0.1 bar) to 218 psig (15 bar); 2.9 psig (0.2 bar) to 290 psig (20 bar); ≤ 5.8 psig (0.4 bar) to 363 psig (25 bar)

Sensor Element Type

Integrated resistance thermometer Pt 100, per DIN EN 60751

Temperature Measurement Range

−4 °F to +176 °F (−20 °C to +80 °C)

Temperature Resolution

1 °K

Sensor Element Dimensions

1.25″ Ø × 7.5″ long, 13′ cable (32 mm Ø × 190 mm long, 4.3 m cable)

Sensor Element Material

PE (polyethylene); compatible with all petroleum fuel products

Sensor Housing

Stainless steel with dry, ceramic-capacitive sensor element

Sensor Element Protection

IP 68 (30 bar)

Vent Pipe Enclosure

Powder-coated aluminum; 4.25 × 5.5 × 15″ (108 × 140 × 380 mm)

Vent Pipe Dimensions

4.25 × 5.5 × 15″ (108 × 140 × 380 mm)

Vent Pipe Mounting

Standard 2″ NPT

Cable Connections

YG95 234 / MIL-C-5015 bayonet quick disconnects (×2)

Network Configuration

Up to 4 units daisy-chained per 8240 Tactical Data Unit

Hazardous Area Approvals

ISA/CSA: Class 1, Division 2, Groups C and D; ATEX/IECEx: Ex II 3(1)G Ex nA [ia Ga] IIB T5 Gc (−40 °C ≤ Ta ≤ 85 °C)

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If you have questions not covered here, please contact the Cognesense support team for assistance.

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Can the 7660 TFG be used with fuel types other than JP-8 or diesel?

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Yes. The stainless-steel housing and ceramic-capacitive sensor element are compatible with all petroleum fuel products, including JP-8, Jet-A, diesel, and motor gasoline. The sensor element does not contact the fuel — it measures hydrostatic pressure through the tank wall — so product compatibility is not a limiting factor.

How many 7660 TFGs can be connected to a single system?

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Up to four 7660 TFGs daisy-chain on a single power and communications loop to one Varec 8240 Tactical Data Unit. For larger fuel points, multiple TDUs can be deployed and their data consolidated through the TacFuels® computing device running FuelsManager®.

Is the 7660 TFG approved for use in hazardous areas?

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Yes. The 7660 TFG is certified to ISA/CSA Class 1, Division 2, Groups C and D for North American installations and to ATEX/IECEx Ex II 3(1)G Ex nA [ia Ga] IIB T5 Gc for international deployments, with an ambient range of −40 °C to +85 °C.

How does the 7660 TFG integrate with SCADA or host inventory systems?

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The 7660 TFG outputs 4–20 mA (HART) to the Varec 8240 TDU, which feeds the TacFuels® computing device running FuelsManager®. For integration with external SCADA, DCS, or other host inventory platforms, the Varec 8250 Tactical Interface Converter bridges TacFuels field data to those systems. Direct SCADA connection from the 7660 TFG alone is not supported.

What happens to measurement data if the power supply is interrupted?

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The 7660 TFG is a sensor, not a data logger, and does not buffer data onboard. Data continuity during a power interruption depends on the 8240 TDU and the TacFuels® computing device. For sites with unreliable power, ensure a UPS or backup covers the TDU and host computing device.

How is the 7660 TFG removed when a fuel point is relocated?

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Removal reverses installation and takes only minutes. Disconnect the power and communications cables, withdraw the sensor cable from the tank (curling the cable as it comes out to avoid kinks) until the sensor clears the vent plate, then replace the original vent pipe to restore standard configuration. The 7660 TFG can then be redeployed at the next location.

What measurement ranges does the 7660 TFG offer?

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Three pressure ranges are available: 0.1–0.218 bar (1.45 psig–218 psig), 0.2–290 psig (20 bar), and ≤0.4–363 psig (25 bar). Temperature is measured from −20 °C to +80 °C with 1 °K resolution via an integrated Pt 100.

How does the 7660 TFG fit with the rest of the Varec TacFuels® family?

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The 7660 TFG is the primary sensing element. It daisy-chains to the Varec 8240 TDU for tank-side aggregation and control; the Varec 8250 TIC bridges TacFuels® data into external SCADA, DCS, or host systems; and the Varec 9760 TMC provides the tactical mobile command/computing layer running FuelsManager®. Together they form the TacFuels® field-to-command inventory stack.

Summary

With over a century of tank gauging heritage, Cognesense brings the Varec 7660 Tactical Fuel Gauge to military, expeditionary, and disaster-response fuel points that depend on collapsible storage tanks. A direct vent-pipe replacement with MIL-C-5015 quick disconnects, dual pressure and Pt 100 temperature sensing, IP 68 immersion protection, ISA/CSA and ATEX/IECEx hazardous-area approvals, and daisy-chain integration with the 8240 TDU and FuelsManager® make it the field-ready automated gauge for CST fuel points — trusted wherever you need to measure, monitor, and protect what matters most.

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