Troubleshoot Coolant Foaming in Six Simple Steps

Foaming from glycol coolant products can lead to serious operational concerns, like high heat that can shut down a compressor engine.

Often times, foaming is caused by underlying mechanical issues, such as a crack or failing gasket that has not been detected. Glycol can also foam due to contamination, which can be more difficult to identify.

There is a quick test to determine if the foaming issue is mechanical or caused by the coolant.

  1. Collect a small sample in a clean bottle with lid
  2. Fill the bottle roughly half way with coolant and close the lid
  3. Allow any bubbles to collapse, leaving no visible foam on top of the fluid
  4. Shake the bottle vigorously for 30 seconds
  5. Place the bottle on a flat solid surface
  6. Use a timer to record how long it takes for the bubbles to completely collapse

If the bubbles collapse in less than one minute, the foaming issue is likely mechanical. A thorough inspection of the system should reveal a leak. You can specifically check for hairline cracks in heads or leaks in pump seals.

If the bubbles take more than one minute to collapse or do not collapse at all, the issue is likely with the coolant. It is recommended you submit a coolant sample for analysis to determine if the fluid is in good condition or if contaminants were introduced to the system.

We’ve gathered simple steps you can take to troubleshoot these issues and help reduce foaming throughout the life cycle of the coolant:

When off-loading new material into the system: Avoid using air pumps to push it from the truck. Air can result in entrapped bubbles and oxygen can accelerate degradation of the glycol coolant.

When cleaning and replenishing the cooling system: Allow the coolant to settle before operating the system. It will take time for any entrapped air to escape through vents and allowing it to settle will reduce the chance of additional foaming.

When suspecting contamination: Check and clean the system’s vents. Contaminants, like dirt and debris, can be introduced through vents and cause foaming.

When controlling for an unplanned foaming event: It is recommended to add 0.002% (by system volume) UCON™ LB-1145 Anti Foaming Agent. Do not overdose the system as this could cause more foaming. Do not add silicon-based antifoaming agents as these may negatively react with the glycol.

Interested in submitting a sample for analysis or have more questions on coolant foaming? Contact your Dow representative today.

About our products

Formulated Coolant solutions with patented anti-scaling technology combined with reliable additives help provide non-purified water tolerance that extend the service life of a system. Propylene glycol (PG) based NORKOOL™ coolants that are more environmentally friendly are also available. All Dow heat transfer fluids or coolants, are made using only new virgin glycols, made in our facilities, and are 99.99% pure. Recycled glycols are never used.

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