Hot and Cold Water Pipes Sizing
Recommended dimensions hot and cold water pipes.
The table below can be used to determine the maximum numbers of draw offs served by a pipe:
| Nominal bore of pipe | Maximum number of draw offs served | ||||
|---|---|---|---|---|---|
| Flow pipes | Return pipes | ||||
| in | Steel pipe (mm) | Copper pipe (mm) | Head up to 20 m (70 ft) | Head over 20 m (70 ft) | |
| 1/2 | 15 | 15 | 1 | 1 - 2 | 1 - 8 |
| 3/4 | 20 | 22 | 2 - 4 | 3 - 9 | 9 - 29 |
| 1 | 25 | 28 | 5 - 8 | 10 - 19 | 30 - 66 |
| 1 1/4 | 32 | 35 | 9 - 24 | 20 - 49 | 67 - 169 |
| 1 1/2 | 40 | 42 | 25 - 49 | 50 - 79 | 170 - 350 |
| 2 | 50 | 54 | 50 - 99 | 80 - 153 | |
| 2 1/2 | 65 | 67 | 100 - 200 | 154 - 300 | |
- Basins, sinks, showers and similar are regarded as 1 draw off
- Baths and similar are regarded as 2 draw offs
