| 165 / | HD | HEAT EXCHANGE |
| DIG 454 | DD | HAVING SIDE-BY-SIDE CONDUITS STRUCTURE OR CONDUIT SECTION {16} |
| DIG 461 | DD | .~ Plate fins formed with tubular projections which join with projections of adjacent plates to form parallel conduits {1} |
| DIG 462 | | .~.~ Tapering, nested projections {1} |
| DIG 463 | DD | .~.~.~> Conduits oblong in cross section |