| 239 / | HD | FLUID SPRINKLING, SPRAYING, AND DIFFUSING |
| 533.1 | DF | FLUID PRESSURE RESPONSIVE DISCHARGE MODIFIER* OR FLOW REGULATOR* {3} |
| 533.2 | DF | .~ Fuel injector or burner {1} |
| 533.3 | DF | .~.~ Having flow regulator* for reciprocating piston engine {7} |
| 533.4 | DF | .~.~.~ With means to vary or pulse flow within engine cycle {1} |
| 533.5 | | .~.~.~.~ Upstream of flow regulator* |