5-277-04-012-001

For in-tank heating with boiler water in the tubes and cross-contamination protection, the Diamondback tank heater line offers a double-wall two-pass U-bend bundle design; this configuration sits within that range. The vented air gap between tube walls gives a visible telltale leak rather than allowing boiler water and tank contents to mix. Physically, the unit runs a 4-inch shell in a 2-pass arrangement. It carries 3/4-inch O.D. tubes. The build specifies cast iron bonnets, steel shell, and copper (double wall) tubes. Design ratings run to 150 PSI on the shell side, 150 PSI on the tube side, and 375°F maximum temperature. The series sees regular use in glycol-fed storage heating, domestic water storage under double-wall codes, and institutional and health care water storage. This build is designated 5-277-04-012-001.