Orifice Plate - Flow reduction
Orifice Plate - Flow reduction
(OP)
Hi,
We want to fabricate an orifice plate to reduce a flow in a pipe.
To summarize, we have two pumps running at 1,100m³/hr discharging into a treatment system that cannot handle more than 1,800m m³/hr. The pumps do not have a VFD.
Our quick solution is to reduce the flow using an orifice plate. I have base my calculation, to find what size of orifice we should install, on Bernouilli’s derive equation as shown on Wikipedia : https://en.wikipedia.org/wiki/Orifice_plate
My problem is the formula requires a differential pressure.
I don’t have this value, and I could only have it if the orificie plate was already made and installed with two points of pressure measurements.
Does anyone have a way to pass over this issue? Or use another formula?
Thank you,
We want to fabricate an orifice plate to reduce a flow in a pipe.
To summarize, we have two pumps running at 1,100m³/hr discharging into a treatment system that cannot handle more than 1,800m m³/hr. The pumps do not have a VFD.
Our quick solution is to reduce the flow using an orifice plate. I have base my calculation, to find what size of orifice we should install, on Bernouilli’s derive equation as shown on Wikipedia : https://en.wikipedia.org/wiki/Orifice_plate
My problem is the formula requires a differential pressure.
I don’t have this value, and I could only have it if the orificie plate was already made and installed with two points of pressure measurements.
Does anyone have a way to pass over this issue? Or use another formula?
Thank you,





RE: Orifice Plate - Flow reduction
Mike Halloran
Pembroke Pines, FL, USA
RE: Orifice Plate - Flow reduction
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Orifice Plate - Flow reduction
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: Orifice Plate - Flow reduction
This diff pressure at the RO is the permanent pressure loss and not the vena contracta dp. Also take into account any vapor space pressure in the downstream treatment system. For this RO to work, both upstream and downstream pressures at the RO must be relatively invariant with all operating modes you'd expect to have, else you may have to resort to a much more expensive control valve option. And of course, the fluid must be relatively solids free. And also check that the vena contracta pressure at the RO is above the saturation vapor pressure of the fluid you're pumping at the max operating pumping temperature. Typically beta ratio for this RO would be between 0.2 and 0.8, and RO hole dia should be more than 3mm.