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Varec 2910

Power-Free Mechanical Level Switch

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Varec 2910

The Varec 2910 Float & Tape Level Switch is designed for terminal operators, refinery engineers, tank farm safety officers, and EPC project teams who need an independent, power-free alarm layer on bulk liquid storage tanks.

Unlike electronic level switches that rely on sensors, logic circuits, or battery backup, the 2910 FTLS uses a direct-drive stainless-steel cam mechanism to actuate up to six SPDT switches from the motion of the float and tape — no power, no communications electronics, no firmware in the alarm path.

Available in 2, 4, or 6 SPDT configurations with independently adjustable set points and NO/NC selection, the 2910 drives annunciators, relays, solenoids, and horns at defined high-high, high, low, and low-low tank levels.

Explosion-proof die-cast aluminum construction, IP66/NEMA 4 protection, and cFMus plus ATEX/IECEx flameproof approvals (Ex db IIB T5 Gb, Class I Zone 1) qualify the 2910 for hazardous areas across refineries, chemical plants, aviation fuel farms, and product terminals.

The 2910 FTLS direct-mounts to Varec, L&J, GSI, and Sakura float and tape gauges — including the 2500 and 2520 ATG — and replaces the legacy Varec 2557 alarm limit switch without gauge modification, delivering an independent protection layer that programs like API 2350 rely on.

Varec 2910
Varec 2910
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Features

Independent Mechanical Alarm Path

Direct-drive cam actuates switches from float motion without power, electronics, or battery backup, providing a separate alarm layer programs like API 2350 rely on.

Configurable Switch Count

Supplied with 2, 4, or 6 SPDT cam-operated switches, each independently adjustable for set point and NO/NC, covering high-high, high, low, and low-low levels.

Stainless-Steel Direct-Drive Gearing

Stainless-steel gears deliver long service life, ±1/16 in (1.58 mm) switching repeatability, and reliable actuation without drift common to electronic sensor-based switches.

Explosion-Proof Hazardous-Area Construction

Die-cast aluminum enclosure carries cFMus, ATEX, and IECEx flameproof approvals (Ex db IIB T5 Gb) with IP66/NEMA 4 for Class I Division 1/Zone 1.

Direct-Mount Gauge Compatibility

Mounts directly to Varec 2500/2520 ATG, L&J, GSI, and Sakura gauges without brackets or modification, supporting in-service retrofit without tank shutdown.

2557 Legacy Replacement

Replaces the legacy Varec 2557 alarm limit switch on a like-for-like mounting, extending the life of installed float and tape assets without gauge rework.

Applications

  • API 2350 Overfill Protection: Independent mechanical high-level and overfill alarms on petroleum, chemical, and refined product tanks, providing a separate protection layer programs like API 2350 rely on.
  • Pump Protection Low-Level Alarms: Actuates low-level alarms and pump-stop interlocks to protect centrifugal and positive-displacement pumps from run-dry conditions on bulk storage and transfer systems.
  • Relay and Annunciator Automation: Drives relays, solenoids, warning lights, or horns at defined tank levels without communications hardware, enabling basic tank-level automation at sites without a DCS.
  • Hazardous-Area Compliance Alarms: Ex db IIB T5 Gb and Class I Zone 1 approvals support independent mechanical switching where a dedicated non-electronic alarm path is required.
  • Aviation Fuel Farms: Power-free alarm actuation on jet and AV gas storage at hydrant pits, into-plane fueling, and bulk farms, supporting JIG-aligned practices at unattended sites.
  • Legacy Gauge Upgrades: Drop-in replacement for the Varec 2557 plus compatibility with L&J, GSI, and Sakura gauges enables alarm capability across heterogeneous fleets without wholesale replacement.
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Specifications

Parameter

Specification

Switch Options

2, 4, or 6 SPDT cam-operated switches; 2/4: 180° adjustable dwell; 6: 18° adjustable dwell; independently adjustable set points

Switch Configuration

Each switch independently adjustable for set point and normally open / normally closed

Repeatability

±1/16 in (1.58 mm) typical

Available Ranges

0–25 ft, 0–50 ft, 0–100 ft (0–7.5 m, 0–15 m, 0–30 m)

Switch Ratings

Up to 11 A @ 125/250/277 VAC; 4 A @ 125 VAC (tungsten lamp); 1/3 HP @ 125 VAC / 250 VDC; 1/2 A @ 125 VDC; 1/4 A @ 250 VDC

Operating Temperature

–40 °F to +185 °F (–40 °C to +85 °C)

Enclosure

Explosion-proof die-cast aluminum; IP66 / NEMA 4

Conduit Entries

Transmitter enclosure: 2 × 3/4″ NPT; terminal junction box: 2 × 3/4″ NPT

Approvals

cFMus (US/Canada); ATEX/IECEx flameproof Ex II 2G, Ex db IIB T5 Gb; Class I Zone 1 (–20 °C ≤ Ta ≤ +85 °C); IP66

Power Requirements

None — fully mechanical switch actuation

Gauge Compatibility

Direct-mount to Varec 2500 / 2520 ATG, L&J, GSI, Sakura float and tape gauges

Legacy Replacement

Drop-in replacement for Varec 2557 alarm limit switch

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

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Does the 2910 FTLS provide communications output?

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No. The 2910 FTLS is a limit-switch-only device; its outputs are hardwired SPDT contacts. For digital protocol output and RTD temperature integration alongside the mechanical alarms, specify the 2920 Float & Tape Transmitter. Both devices can be installed on the same gauge simultaneously so one installation provides both alarm switching and digital level and temperature data.

How many alarm set points can I configure?

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Choose 2, 4, or 6 SPDT switches, each with an independently adjustable set point and NO/NC selection. This supports separate high-high, high, low, and low-low alarm levels from a single installation without additional switching hardware.

What electrical loads can the switches drive?

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Typical ratings include up to 11 A at 125, 250, or 277 VAC; 4 A at 125 VAC for tungsten filament lamps; 1/3 HP at 125 VAC or 250 VDC; 1/2 A at 125 VDC; and 1/4 A at 250 VDC. Confirm full electrical ratings from the datasheet before specifying relay or solenoid loads.

Is the 2910 FTLS suitable for hazardous-area installations?

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Yes. The 2910 carries cFMus (US and Canada) and ATEX/IECEx flameproof approvals (Ex db IIB T5 Gb) with IP66 protection, suitable for Class I Division 1 and Zone 1 hazardous locations across refineries, chemical plants, and terminals.

Which gauges does the 2910 FTLS mount to?

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The 2910 direct-mounts to most mechanical float and tape gauges, including the Varec 2500 ATG, Varec 2520 ATG, L&J, GSI, and Sakura units. It also replaces the legacy Varec 2557 alarm limit switch as a drop-in upgrade on existing installations with no gauge rework.

Does the 2910 need power or battery backup?

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No. Switch actuation is fully mechanical via a direct-drive cam and stainless-steel gear train. The 2910 continues to function correctly during and after power outages, which is the reason it qualifies as an independent protection layer in API 2350 programs.

Can the 2910 and 2920 FTT be installed on the same gauge?

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Yes. The 2910 FTLS and 2920 Float & Tape Transmitter can be installed on the same float and tape gauge simultaneously. This gives the tank both an independent mechanical alarm layer (2910) and digital protocol output with RTD temperature (2920) from a single gauge installation.

Does the 2910 align with API 2350 overfill prevention principles?

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The 2910 FTLS provides a mechanically independent, power-free alarm path that is separate from the primary level gauge and its electronics. This architecture supports API 2350 overfill prevention programs, which rely on independent protection layers. Site-specific conformance depends on the full overfill prevention plan; consult your Cognesense application engineer to align the 2910’s configuration with your LOPA and SIL requirements.

Summary

With over a century of tank gauging and overfill protection heritage, Cognesense continues to set the global standard for independent mechanical alarm layers. The Varec 2910 FTLS delivers power-free cam-operated SPDT switching across 2, 4, or 6 independently configurable set points, with Ex db IIB T5 Gb and IP66/NEMA 4 approvals for hazardous-area service and direct-mount compatibility with Varec, L&J, GSI, and Sakura float-and-tape gauges. The result is a dedicated, audit-ready alarm path trusted wherever you need to measure, monitor, and protect what matters most.

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