GURU® Flag and Key


The key at the end of the cable on the GURU® Flag and Key is inserted into the cartridge end after warming the nose of the cartridge. The flag can then be attached to the side of the locomotive by its magnetic base to provide an external indication that the GURU® has been disabled. This will help to prevent leaving the key in the valve resetting stem, defeating the valve’s function, and possibly resulting in freeze damage to the locomotive.

When the locomotive’s cooling system is back up to temperature, the key can easily be removed and the GURU® is again armed to protect the locomotive.

Typical Applications

The GURU® Flag and Key is required to be used in conjunction with GURU® valves with anti-tampering caps to keep the valve from “popping” during a  locomotive’s cooling system refill process. The anti-tampering caps are designed so the valve’s resetting stem is not accessible, eliminating the ability to leave a penny or washer tucked up under it.

GURU® Flag and Key

Design Features

  • Magnetic base attaches to locomotive body or running board
  • Flashing light for increased visibility
  • 3 lanyards for easier maintenance
  • Long cable length for easy placement
  • Quick release pin inserts into dome GURU® cap to eliminate tampering abilities


  • Allows refilling of locomotive with cool water without tripping of GURU® Plugs
  • Alerts to the presence of deactivated GURU® Plugs
  • Minimizes risks of deactivated GURU® Plugs
  • Eliminates ability to tamper with the valve resetting stem
  • Can be used with Magnum and DL 2.1 Plugs