5-277-04-054-001

Configured for in-tank heating with boiler water in the tubes and cross-contamination protection, this configuration carries the double-wall two-pass U-bend bundle construction that defines the Diamondback tank heater range. The vented air gap between tube walls gives a visible telltale leak rather than allowing boiler water and tank contents to mix. Dimensionally it is a 4-inch shell unit in a 2-pass arrangement. It carries 3/4-inch O.D. tubes. Material selection covers cast iron bonnets, steel shell, and copper (double wall) tubes. Operating limits are 150 PSI on the shell side, 150 PSI on the tube side, and 375°F maximum temperature. This build is designated 5-277-04-054-001. Common applications are domestic water storage under double-wall codes, glycol-fed storage heating, and institutional and health care water storage.