| 165 / | HD | HEAT EXCHANGE |
| DIG 135 | DD | MOVABLE HEAT EXCHANGER {4} |
| DIG 139 | DD | .~ Fully rotatable {5} |
| DIG 156 | DD | .~.~ Hollow cylindrical member (e.g., drum, etc.) {3} |
| DIG 159 | | .~.~.~ With particular flow path or defined fluid chamber (e.g., annulus, spiral, etc.) {1} |
| DIG 160 | DD | .~.~.~.~> Concentric shells define annular flow space {1} |