| 165 / | HD | HEAT EXCHANGE |
| DIG 454 | DD | HAVING SIDE-BY-SIDE CONDUITS STRUCTURE OR CONDUIT SECTION {16} |
| DIG 471 | DD | .~ Plural parallel conduits joined by manifold {15} |
| DIG 478 | | .~.~ Separate means employed for mechanical attachment and hydraulic seal of conduit ends to header plate |