947 Ground Level Checker Option for Top Mounted Level Control Switches

In an effort to prevent costly and dangerous spills, many major oil companies, pipelines and marketing terminals have established a requirement to check the operation of tank safety switches.  To meet this ever demanding need, the Omnitrol Ground Checker Option has been developed.

The Ground Level Checker Option is a factory installed option which when assembled to a typical top mounted Omnitrol unit provides the unique capability of ground level or tank top checking while maintaining the high quality components and standard features of the Omnitrol Liquid Level Control.  Through the application of this design, a positive check can be made by simply operating a balanced lever arm mechanically linked to the switch mechanism of the control without interrupting normal operation or exposing the operator and/or system to hazardous conditions. Although the checker can be applied to any standard top mounted control, the Model 610 or 710 (for liquids) and Model 621 or 721 (for floating roof and internal floating pans) are most often recommended.

The checker is mounted on the standard 2-1/2” NPT screwed cast iron mounting connection for standard screwed installations or can be mounted using a reducing companion flange, (customer supplied).  It is designed for a maximum pressure of 25 PSI, which is in excess of the pressures commonly encountered in chemical and petroleum storage tanks, and uses Viton O-Ring seals. 

These devices are intended to be a primary source of high (single stage) or high-high (dual stage) level alarm control and are often used in conjunction with the tank gauging equipment.


  • Checks operation of tank safety switches
  • For use with 610/710, 621/721, 613/713, 616/716
  • Ground Level or tank top operation
  • Applicable to cone roof or floating roof tanks, and internal floating pans
  • Checker is supplied with 10 feet of stainless steel beaded chain. Maximum 60 Feet Optional

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