Problems of capacity, cavitation and higher energy consumption in pumps are often the result of the conditions of the suction side of the pumps.
In general - as a general rule - maintain the flow rate of suction fluid in boiling liquids below the following values:
| Pipe hole | Maximum boiling fluid speed | ||
|---|---|---|---|
| inch | millimeters | m/s | pump/s |
| 1 | 25 | 0,3 | 1 |
| 2 | 50 | 0,3 | 1 |
| 3 | 75 | 0,3 | 1 |
| 4 | 100 | 0,3 | 1 |
| 6 | 150 | 0,35 | 1.1 |
| 8 | 200 | 0,38 | 1.2 |
| 10 | 250 | 0,45 | 1,5 |
| 12 | 300 | 0,45 | 1,5 |
Boiling liquids – due to cavitation – can be extremely difficult to pump. If the pressure at any point within a bomba drops below the vapor pressure of the liquid being pumped, vaporization or cavitation will occur. For example, water 100 o F (38 o C) boils or vaporizes if exposed to a vacuum of 28 in Hg . The problem with cavitation increases with higher temperatures.
Source: https://www.engineeringtoolbox.com/pump-sation-flow-velocity-boiling-fluid-d_230.html
