Freeze Protection for Hydrant Backflow Meters

Freeze Damage

When colder temperatures are in the forecast, you will need to take steps to winterizing the hydrant backflow assembly meters you have on loan at your project site.  Each year, TVWD loses one or two hydrant backflow meters to freezing damage.  The company using it ends up paying for parts & labor to repair, or a new hydrant backflow meter (HBM).

If your loan/usage period will last into the winter, you will need to take steps to properly protect TVWD’s hydrant backflow meters.

  • The HBM should be drained at the end of business every day.
    • Turn the hydrant valve off
    • Disconnect the attached hose
    • Fully open the gate valve
    • The HBM should discharge water from the relief valve and also drain from the gate valve
  • You may also want to consider insulating the HBM.
    • If wrapped or insulated, do NOT cover the opening of the relief valve
    • Do not wrap the entire fire hydrant as TVF&R may need to access the hydrant for firefighting purposes

What to do if the HBM freezes and will not flow water?

  • Contact the person who assisted with the deployment of the HBM or any member of the Backflow team.  You may also call TVWD’s main phone number (503-848-3000) to report the frozen HBM.
  • Do NOT heat the HBM with a torch.
    • The epoxy paint will blister/burn
    • Rubber and plastic internal parts will melt
    • Heating the frozen HBM may crack the housing/case

If you will not be accessing water during the colder/wetter months, it highly recommended to end the loan period.  If your HBM experiences freezing damage, your project will not be given priority for a replacement.  As with a typical loan, the HBMs are allocated on a first come first served basis dependent on inventory levels.  If none are available, your company will be put on the wait list.

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