PRV vs Orifice for fluctuating flow

[S4in]

Hello all!

I have a fuel return pipe from a diesel engine that naturally have a fluctuating flow. Pressure pulses in the system was noted to be reduced when the PRV was replaced by an fixed restriction (orifice) but unfortunately it is a bit difficult to explain why.
Anybody have any good ideas on why this effect is experienced?

Best Regards,
Sai

 

[BigInch]

PRV's PID settings were wrong?

http://virtualpipeline.spaces.msn.com

"What gets us into trouble is not what we don't know, its what we know for sure" - Mark Twain

 

[insult2injury]

Has to be in the tuning and response time of the controls.

I2I

 

[S4in]

Thank you for your answers!
The PRV was of the cheap type, spring regulated with no active PID control.
I agree with you I2I, the spring was not able to respond quickly enough to the pulses, and therefore making the problem worse instead of helping to resolve it.

Br,
Sai

 

[budt]

Are you aware that the Orifice fix will allow pressure beyond it to build on its Outlet to whatever Inlet pressure is when flow demand changes. A Pressure Compensated Orifice would keep this from occuring.

On top of that, If the Use Demand is no longer required and inlet flow is left on, pressue after the orifice will comtinue to build to the same pressure as the Inlet.


Bud Trinkel, Fluid Power Consultant
HYDRA-PNEU CONSULTING