| 165 / | HD | HEAT EXCHANGE |
| DIG 355 | DD | HAVING SEPARATE FLOW PASSAGE FOR TWO DISTINCT FLUIDS {7} |
| DIG 356 | DD | .~ Plural plates forming a stack providing flow passages therein {11} |
| DIG 385 | DD | .~.~ Bent sheet forming a single tube {1} |
| DIG 386 | | .~.~.~ To form only air passages |