| 122 / | HD | LIQUID HEATERS AND VAPORIZERS |
| 459 | DF | STEAM TREATMENT {7} |
| 479.1 | ![]() | .~ Automatic heat regulation of superheater {6} |
| 479.2 | DF | .~.~> Having gas recirculation |
| 479.3 | DF | .~.~> Having flame positioning |
| 479.4 | DF | .~.~> With variable firing |
| 479.5 | DF | .~.~> Having dampers |
| 479.6 | DF | .~.~> Plural furnaces |
| 479.7 | DF | .~.~> Once through |