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Omnitrol  664F/666F/668F

Flanged Chamber Mounted Level Switches

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Omnitrol  664F/666F/668F

For terminal operators, refinery and chemical engineers, boiler and heater treater operators, water and wastewater utilities, and EPC specifiers who need high-integrity point-level control on pressurized vessels or bypass chambers, the Omnitrol 664F / 666F / 668F delivers rugged flanged chamber construction, factory specific-gravity calibration, and predictable switching differentials across a wide range of process fluids.

Unlike float switches or capacitance probes that can foul, drift, or require frequent field adjustment, the 66xF family uses displacer-based magnetic switching inside a forged flanged chamber that is hydrostatically tested to 1.5× its rated pressure. Each unit is tuned at the factory to the process liquid density, providing accurate alarm actuation with no field calibration required.

This design makes the series ideal for API 2350 overfill protection, separator service, heater treaters, steam systems, and pressurized tank bypass chambers, ensuring safe isolation, long service life, and reliable switching in critical industrial environments.

Omnitrol  664F/666F/668F
Omnitrol  664F/666F/668F
Omnitrol 664F/666F/668F

Features

Flanged Chamber Construction

Integrates directly with ANSI 150/300/600 (and up to 1000-lb) flange classes, meeting plant piping standards and enabling simple maintenance isolation with standard spool pieces.

Factory Specific-Gravity Calibration

Each unit ships pre-set for your fluid SG up to 1.7, ensuring correct actuation points and minimizing field adjustment time during commissioning.

Hydrostatic Proof Testing

Every chamber undergoes hydrostatic testing at 1.5× maximum design pressure, providing integrity confidence and reducing HAZOP findings at startup.

Graphite Displacer Standard

Provides excellent chemical compatibility across petroleum, petrochemical, chemical, and industrial applications without requiring special material upgrades.

Multiple Switch Housing Options

Weather-resistant (NEMA 4), explosion-proof/vapor-proof (Class I Groups B/C/D, Class II Groups E/F/G), and explosion-proof/rain-tight configurations available.

UL and CSA Approvals

Certified for hazardous area classifications, ensuring compliance with plant safety standards and simplifying MOC (Management of Change) processes.

Applications

  • Heater Treater Alarms: Flanged chamber handles up to 1000 psig at 500°F for safe, code-friendly high-pressure cutoff without intrusive wetted switches.
  • Light Product Control: Models 666F/668F deliver tight switching differentials at low specific gravities, minimizing false trips and providing predictable control gaps.
  • Pressurized Tank Bypass: External chamber isolates the sensing element, allowing head service without opening the vessel and improving plant uptime.
  • Separator Interface Service: Can be configured for interface applications on special order by specifying gravities of both liquids for accurate phase separation.
  • Chemical Process Vessels: Graphite displacer and multiple material options provide compatibility with aggressive chemicals, acids, and caustic services.
  • Petroleum Storage Terminals: Rugged construction and factory calibration ensure reliable inventory management and overfill protection in demanding tank farm environments.
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Specifications

Models

664F (4″ body), 666F (6″ body), 668F (8″ body) flanged chamber, single actuator.

Pressure/Temperature

Up to 1000 psig @ 500 °F (materials/options per Table G).

Specific Gravity (max)

1.7. Factory SG set; SG affects switching differential per published table.

Materials

Carbon steel, 304 SS, 316 SS chambers; graphite displacer standard.

Housings

Weather-resistant, Explosion-proof/Vapor-proof (Cl I, Gr B/C/D; Cl II, Gr E/F/G), Explosion-proof/Rain-tight variants.

Switching Elements

Multiple SPDT/DPDT micro options with published resistive ratings (E, G, H, M, S families).

Connections

ANSI 150/300/600 (higher classes optional). Dimensional tables published by model/pressure class.

Approvals

UL & CSA (per model options).

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Do these switches require field calibration?

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No — they are factory calibrated to your liquid’s specific gravity.

Can this model handle high-pressure and high-temperature service?

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Yes — up to 1000 psig and 500 °F, depending on configuration.

Why is the flanged design beneficial for high-pressure applications?

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The flanged design simplifies the process for maintenance isolation using standard spool piece removal. It also provides a highly robust, secure, and easily verifiable pressure seal that meets standard plant piping specifications. This is critical in high-pressure applications where integrity is paramount.

What is the significance of the hydrostatic proof test?

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The hydrostatic proof test verifies the physical integrity of the welded chamber by subjecting it to 1.5 times the maximum rated pressure before it leaves the factory. This provides an extra layer of quality assurance and regulatory compliance, confirming the vessel integrity for high-pressure service.

Can I service the switch without opening the vessel?

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Yes — the external chamber design allows head removal without tank entry.

What applications benefit most from the 66xF design?

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Pressurized vessels, heater treaters, bypass chambers, separators, boilers, API 2350 overfill points.

When should I select the 666F or 668F over the 664F?

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Choose 666F/668F when handling lower-SG fluids requiring tighter switching differentials.

When should I choose the 66xC or 66xW versions instead?

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  • 66xC for compact NPT-connected short chambers
  • 66xW for long welded chambers or custom nozzle spacing
  • 76x series for dual setpoints
Summary

The  Omnitrol  664F/666F/668F combines a process-piping-ready flanged chamber, factory SG calibration, tight and predictable switching differentials, and 1000 psig @ 500 °F ratings to deliver dependable level alarm and control on pressurized vessels and bypass chambers. With broad housing/switch options, UL/CSA approvals, and interface capability, it’s a low-risk, spec-clean choice for EPCs and plant engineers who want reliable performance without intrusive wetted switches or tuning hassles.

L&J
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