| 122 / | HD | LIQUID HEATERS AND VAPORIZERS |
| 459 | DF | STEAM TREATMENT {7} |
| * | | .~ Superheater {8} |
| 480 | DF | .~.~> Damper-controlled |
| 481 | DF | .~.~> Firebox |
| 482 | DF | .~.~> Fire tube in steam space |
| 483 | DF | .~.~> Indirectly heated |
| 484 | DF | .~.~> Separate charges |
| 485 | DF | .~.~> Separate furnace |
| 486 | DF | .~.~> Steam dome |
| 487 | DF | .~.~> Water-injected |