| 165 / | HD | HEAT EXCHANGE |
| DIG 355 | DD | HAVING SEPARATE FLOW PASSAGE FOR TWO DISTINCT FLUIDS {7} |
| DIG 442 | DD | .~ Conduits {5} |
| DIG 443 | DD | .~.~ Adjacent conduits with transverse air passages (e.g., radiator core type, etc.) {3} |
| DIG 445 | | .~.~.~ Including transverse corrugated fin sheets |