| 165 / | HD | HEAT EXCHANGE |
| DIG 92 | DD | WITH VALVE OR MOVABLE DEFLECTOR FOR HEAT EXCHANGE FLUID FLOW {6} |
| DIG 126 | | .~ Total flow rate through heat exchanger controlled by valve {3} |
| DIG 127 | DD | .~.~> Stove pipe drum {1} |
| DIG 129 | DD | .~.~> Valve regulates flow through housing enclosing heat exchanger {1} |
| DIG 131 | DD | .~.~> Single-confined-fluid radiator for heating ambient air |