4 replies to this topic

[Vegeta]

Dears,

 

Can any one help me in how to determine if a liquid PCV will cavitate or not? Also, in the PCV process data sheet there is a space to be filled for critical pressure. Is it the thermodynamic critical pressure or it is something else? why is it needed?

 

Regards,

[fallah]

Vegeta,

 

When in the vena contracta a pressure lower than the saturation pressure is reached then the liquid evaporates and forms vapor bubbles. If due to pressure recovery, the downstream pressure is higher than the vapor pressure in the vena contracta, then the vapor bubbles totally or partially implode and cavitation will be happened.

 

And yes, it's thermodynamic critical pressure...and needed as per above criteria for cavitation happening...

Edited by fallah, 28 September 2014 - 05:32 AM.

[Vegeta]

Fallah,

I understood the first part of your reply ( vapor pressure part ). However, I didn't get the second part. Can you explain it in more details, please?

Sorry for any inconvenience.

Regards,

[breizh]

http://www.flowserve...ENBR0068-00.pdf

http://www.controlen...8d5c4b8279.html

Consider these document and link .

 

Breizh

Edited by breizh, 29 September 2014 - 12:33 AM.

[fallah]

Vegeta,

 

The critical pressure is needed to predict if cavitation would be occurred. If vapor pressure is more close to critical pressure, the possibility and intensity of cavitation is lower...

Edited by fallah, 28 September 2014 - 08:02 AM.