| 137 / | HD | FLUID HANDLING | 
| 455 | DF | LINE CONDITION CHANGE RESPONSIVE VALVES {11} | 
| 511 | DF | .~ Direct response valves (i.e., check valve type) {14} | 
| 528 |  | .~.~ Reciprocating valves {5} | 
| 529 | DF | .~.~.~> Plural biasing means | 
| 530 | DF | .~.~.~> Cam means for adjusting and fixing bias | 
| 531 | DF | .~.~.~> Varying effective lever arm | 
| 532 | DF | .~.~.~> Weight biased {2} | 
| 535 | DF | .~.~.~> Spring biased {5} |