DWU Series Double-Wall Liquid Heat Exchangers

Double-Wall Protection on a Pumped Water Circuit

The DWU pairs the WU's pumped shell-side arrangement with double-wall tube construction. Two tube walls in intimate contact carry the heat; the vented path between them carries any leak to the outside of the unit where it can be seen.

The most common application is a boiler loop heating domestic water. The boiler circuit carries treatment chemicals and is not potable. The domestic circuit is. Where those two meet across a single tube wall, many jurisdictions require a second barrier, and the DWU is the catalogued way to provide one without moving to engineered construction.

Glycol circuits raise the same question. Even propylene glycol systems carry inhibitor packages, and a heat transfer fluid crossing into potable water is a contamination event regardless of how benign the base fluid is. Double-wall construction removes the question rather than arguing about it.

Sizing allows for the extra resistance. The double-wall interface is a real thermal barrier, so a DWU carries more surface than a WU of equivalent duty. The 5-267 catalogue range reflects that, and the shell diameters run to 12 inches rather than the WU's 30.

Naval brass tubesheets and cast iron bonnets are standard across the range, with the same removable U-tube bundle and 2, 4 and 6 pass tube-side options as the rest of the family.