| 165 / | HD | HEAT EXCHANGE |
| DIG 9 | DD | HAVING A SOLID HEAT STORAGE MASS FOR ABSORBING HEAT FROM ONE FLUID AND RELEASING IT TO ANOTHER (I.E. REGENERATOR) {5} |
| DIG 10 | DD | .~ Cleaning storage mass {2} |
| DIG 11 | | .~.~ Reciprocating cleaner device (e.g. scraper, sprayer) |