Friction Loss Factors
Some examples of the Friction Loss Factor values, for piping circuits (may be added for several singularities):
| 45° elbow, standard | 0.35 |
| 90° elbow, standard | 0.75 |
| 90° elbow, long radius | 0.45 |
| Tee, along run, branch inactive | 0.4 |
| Tee, used as elbow | 1.5 |
| Gate valve, open | 0.17 |
| Gate valve, ¾ open | 0.9 |
| Gate valve, ½ open | 4.5 |
| Gate valve, ¼ open | 24 |
| Diaphragm valve, open | 2.3 |
| Diaphragm valve, ¾ open | 2.6 |
| Diaphragm valve, ½ open | 4.3 |
| Diaphragm valve, ¼ open | 21 |
| Butterfly valve, 5° | 0.24 |
| Butterfly valve, 20° | 1.54 |
| Butterfly valve, 40° | 10.8 |
| Butterfly valve, 60° | 11.8 |
| Non-return valve, disk | 10 |
| Non-return valve, ball | 70 |
| Water meter, disk | 7.0 |
| Water meter, piston | 15 |
| Water meter, Turbine | 6.0 |