Orifice plate selection

[John Doney]

Hey everybody,

I'm coming to the point in my build where I need to start thinking about the orifice plates. I plan on having a normally usable range of 1-400cfm with a max of 600cfm.( using eight motors)

If I understand correctly the orifice plate will always be mounted inside the bench when a cylinder head is being flow tested with no plate on top. An additional plate is added on top of the bench when calibrating for testing intake ports (the inside plate will flow more air than the top plate). The calibration is done at 28" water column with the plate on top of the bench. The inside plate could also be tested at 16"wc with a larger plate on top of the bench? So for plate selection should I get a 100,200,300, 400, 600, and one plate slightly larger for the calibration of the 600? Is my understanding of orifice plate calibration correct?

Any help would be greatly appreciated!

[Brucepts]

A PTS Flowbench build?

If so I have a set of 4 plates worked out for a 0-600cfm range that are internal or calibration plates, if you are going digital with a PTS DM

[John Doney]

Yes this is a PTS build using the 40" digital manometer. I remembered seeing the plates in your youtube video so I went ahead and ordered them up.

Thanks again Bruce!