| 165 / | HD | HEAT EXCHANGE |
| DIG 454 | DD | HAVING SIDE-BY-SIDE CONDUITS STRUCTURE OR CONDUIT SECTION {16} |
| DIG 500 | | .~ Side-by-side conduits with fins {2} |
| DIG 501 | DD | .~.~> Plate fins penetrated by plural conduits {2} |
| DIG 505 | DD | .~.~> Corrugated strips disposed between adjacent conduits |