I need the regulatory / engineering definition of a double wall heat exchanger. Is air required to distinguish one wall from the other or can it be oil, water etc? I am in Idaho but any state or federal regulation links will be helpful.
There are several different types of double wall heat exchangers depending upon if you are dealing with Plate and Frame exchangers or with Shell and Tube exchangers, and also if you are dealing with hazardous materials, or if you are just trying to avoid mixing of the liquid streams if there should be a leak. Your best bet would be to call a few heat exchanger manufacturers and discuss the double wall concept with them.
