Using the nomogram and charts.
| Types of fitting |
Equivalent pipe length in m. |
| Inner pipe diameter in mm. |
| 25 |
40 |
50 |
80 |
100 |
125 |
150 |
| Seat valve |
|
6-Mar |
10-May |
15-Jul |
25-Oct |
15-30 |
20-5C |
25-60 |
| Diaphragm valve |
|
1.2 |
2 |
3 |
4.5 |
6 |
8 |
10 |
| Gate valve |
|
0.3 |
0.5 |
0.7 |
1 |
1.5 |
2 |
2.5 |
| Elbow |
|
1.5 |
2.5 |
3.5 |
5 |
7 |
10 |
15 |
| Bend r=d |
|
0.3 |
0.5 |
0.6 |
1 |
1.5 |
2 |
2.5 |
| Bend r=2d |
|
0.15 |
0.25 |
0.3 |
0.5 |
0.8 |
1 |
1.5 |
| Hose connection T-piece |
|
2 |
3 |
4 |
7 |
10 |
15 |
20 |
| Reducer |
|
0.5 |
0.7 |
1 |
2 |
2.5 |
3.5 |
4 |
Table of equivalent pipe lengths for valves and fittings as used on air distribution systems
Determine the diameter of a suitable air main for the distribution of 6 m3 min-1 FAD.
System pressure is 6 bar, the length of the pipe run is 175 metres, and a maximum pressure drop of 0.3 bar is allowed.
The distribution main must also include the following : . 4bends(r=2d) . 2 elbow fittings . 6 tee connectors . 2 diaphragm valves.