| in any of the configurations | 3 | other |
| valve → be made from → material | 4 |
| valve → be made of → material | 3 |
| valve → be formed of → any of the materials | 3 |
| negative | neutral | positive |
| 0.119 | 0.748 | 0.133 |
| Raw frequency | 10 |
| Normalized frequency | 0.181 |
| Modifier score | 0.500 |
| Perplexity | 111.786 |