5-277-12-108-001

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 12-inch shell unit, 108-inch shell length 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. On the ratings side, expect 150 PSI on the shell side, 125 PSI on the tube side, and 375°F maximum temperature. Common applications are glycol-fed storage heating, potable water storage tanks, and domestic water storage under double-wall codes. This build is designated 5-277-12-108-001.