Problems with cavitation in the pipeline

[wkca80]

I have two problems regarding the vaporization in the pipeline

1)
In the textbook, it is common to find examples with a steady flow and pressure.
If regional pressure is lower than the fluid vapor pressure, vaporization will occur, am I correct?
If suction pressure is 20kPa, sum of loss (elevation, friction, and minor losses) is 18kPa, and the fluid vapor pressure is 2.3kPa, vaporiation will happen, isn't it?

2)
How can I evaluate the same problem if the pump type is changed to pistion pump?
Unsteady suction pressure is induced periodically inside the pipeline, can I carry out the calculation by assuming the averaged suction pressure?
If the estimated peak suction pressure is 30kPa, under what suction pressure value will vaporization happens?

 

[Pkruse]

Or just apply an anti-cavitation coating. I’ve used one supplied by Belzona. Then you can just let it cavitate with no damage.

Don’t forget that vaporization of your working fluid is only one source of cavitation. You also have dissolved gasses to be concerned about. That is normally responsible for a much smaller portion of the damage, but not always.