| 122 / | HD | LIQUID HEATERS AND VAPORIZERS |
|
| 135.1 | DF | FLUE {4} |
| 155.1 |  | .~ Vertical {16} |
| 155.2 | DF | .~.~> With flue baffle |
| 155.3 | DF | .~.~> Having exterior heating flue |
| 155.4 | DF | .~.~> Having corrugated flue |
| 155.5 | DF | .~.~> Having undulating flue |
| 157 | DF | .~.~> Central magazine {1} |
| * | DD | .~.~> Circulation tube {1} |
| 160 | DF | .~.~> Concentric shell {2} |
| 163 | DF | .~.~> Exterior drum |
| 165 | DF | .~.~> Internal water heater |
| 166.1 | DF | .~.~> With internal water tube {12} |
| 182.1 | DF | .~.~> With return fire tube {2} |
| * | DD | .~.~> Spiral water conduit {1} |
| * | DD | .~.~> Standpipe {1} |
| 187 | DF | .~.~> Transverse fire tube |
| 164 | DF | .~.~> Insulated outlet flue |
| 156 | DF | .~.~> Fluid fuel |