Double Wall Plate Heat Exchangers
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The Monday Morning Minutes of the last two weeks introduced some differences between plate heat exchangers. Two of the products featured were the double wall plate & frame and double wall brazed plate heat exchangers. We have received many calls regarding these models and Michigan and Ohio plumbing codes.
The plumbing code is very specific in its requirement for double wall with an air gap AND leak paths to atmosphere. There are plate heat exchangers in the market which have double wall construction with an air gap, but the leak path to atmosphere either does not exist or could get plugged. Obviously, since air is an insulator, these products have higher heat transfer and may, therefore, be lower cost but they may not meet code. Worst yet, should a leak does occur, there is no indication until the second plate is breached and there is a cross contamination of fluids. This condition may affect the health of people in the buildings.
The Bell and Gossett double wall heat exchangers provide the protection of “TRUE” double wall construction, the air gaps required by code, and multiple leak paths for your peace of mind if any single leak path plugs.
In addition, plate exchangers are available in ASME and non-code construction. These vessels are under pressure in your HVAC and Plumbing systems and we recommend the specification of an ASME label and testing.
We would recommend your double wall specifications include ASME stamp and U-1 report, double wall construction, air gaps, and multiple leak paths to atmosphere.
Click here for a copy of the Suggested specifications from R L Deppmann
Disclaimer: R. L. Deppmann and it’s affiliates can not be held liable for issues caused by use of the information on this page. While the information comes from many years of experience and can be a valuable tool, it may not take into account special circumstances in your system and we therefore can not take responsibility for actions that result from this information. Please feel free to contact us if you do have any questions.