Double Wall PHE Drawing

Double-Wall Accu-Therm Eliminates Product Mixing

Mueller's double-wall Accu-Therm plate heat exchanger is constructed with two identical plates nested together. Each of these double-wall pairs are fully welded at the port locations, creating a two-layer heat transfer wall. These pairs are then assembled into the heat exchanger as a normal single plate would be installed.

In the unlikely event that your product might penetrate through one of the plates, the fluid exits between the two plates at the edge of the unit. This allows for immediate visual monitoring of the unit as well as providing maximum protection available from mixing of the products.


  • Acid heating/cooling.
  • Potable water heat exchangers.
  • Lubricating oil coolers.
  • Transformer oil coolers.
  • Quench oil cooling.
  • Any process that demands the highest security from mixing of the two fluids.


  • Reduced fouling.
  • Close-approach temperatures.
  • Low-pressure drop design.
  • Compact size.
  • Reduced weight.
  • Low hold-up volume within the heat exchanger.
  • Reduced cost.
  • Multiple fluid capabilities.

Design and Construction

AT Plate Pairs

The feature that makes the Accu-Therm heat exchanger so useful is external leak protection, which provides double protection with its double-wall construction. Any hole in the plate surface allows the product to leak to the edge of the plate pair for immediate visual detection.

As with every standard Accu-Therm design, any gasket failure also permits the leaking fluid to be safely diverted to the edge of the plate pair. Again, this allows for immediate detection and security that the fluids are not mixing.

The double-wall Accu-Therm has all of the features of the standard design, with only a small impact on thermal efficiency, by adding the second wall of the plate pair.