| 137 / | HD | FLUID HANDLING |
| 315 | DF | WITH REPAIR, TAPPING OR ASSEMBLY MEANS {6} |
| 329 | DF | .~ With provision of alternate wear parts {1} |
| 329.01 | | .~.~ Valve heads and/or seats {3} |
| 329.02 | DF | .~.~.~> Opposite duplicate surfaces of unitary structure {1} |
| 329.05 | DF | .~.~.~> Different portions of continuous surfaces |
| 329.06 | DF | .~.~.~> Successively used adjacent independent elements |