2 replies to this topic

[Takechi]

Dear all

 

Can anyone share rule of thumb for permanent pressure loss at Flow meter such as orifice, turbine, vortex, coriolis, etc.? Is it depend on fluid type(liquid, vapor)

 

Can anyone share rule of thumb for minimum pressure drop of Control valve(Globe valve)? Is it depend on fluid type(liquid, vapor)

 

Because I am during design the system with allowable pressure drop is less than 0.5 kg/cm2g.

 

 

Best regards,

 

Salapao

[VeryProfessionalEngineer]

Without knowing more about what you are measuring and controlling and what range of flow rates you might expect there's not much I can tell you.

 

Is 0.5 kg/cm2g the pressure drop for the total system (valve, flowmeter, and whatever other equipment you have)? I'm not sure how much rules of thumb will help you. For control valves, you generally want some percentage of your dynamic pressure drop (not counting set pressure drops like static head) in the system in order for the valve to handle changes in flow and/or fouling. That percentage might be 25-50% depending on the service and how much fouling or flow variation you anticipate. Of course, that all depends on the service too, because I am used to systems with much higher pressure drop. I wouldn't want to comment on flow measurement pressure drop as you may have some niche application for which it would not be applicable. 

[Takechi]

Thank you VeryProfessionalEngineer

 

Salapao