| 165 / | HD | HEAT EXCHANGE |
| DIG 51 | DD | HAVING EXPANSION AND CONTRACTION RELIEVING OR ABSORBING MEANS {2} |
| DIG 52 | DD | .~ For cylindrical heat exchanger {6} |
| DIG 53 | DD | .~.~ Flexible or movable header or header element {3} |
| DIG 54 | DD | .~.~.~ Movable header (e.g., floating header, etc.) {1} |
| DIG 55 | DD | .~.~.~.~ Including guiding means for movable header {1} |
| DIG 56 | | .~.~.~.~.~ Fluid sealing means between movable header and enclosure |