PTS plate CD

[Bakerlite]

What CD are you getting on your PTS calibration plates Bruce?

[Brucepts]

My plates are machined for a .62 Cd sharp edge orifice

[Bakerlite]

Ok thanks, the plates I machined up were based on that CD. I'll send them to a friend and see how close they come to the calculations.
Have you ever had one orifice hole next to another and noticed any effect from having them both open together at the same time?

[Brucepts]

I have not but I know people who have and it's not good

[ftch]

hello bruce the plates I bought from you are a 3.490 and its marked 16"/600

should this be 3.490 16"/660 This works out correctly to the spread sheet.

The other is a 300 28" and measures 2.046 and calculates correctly to the spreed sheet.

The formula at the bottom where I place the flow required and it calculates the diameter , I dont thing I undersatand as I cant get that to match up.

I cant say enough about hoe good this forum is. We have our 12 motor bench running now and are just getting ti the final stages.

Michael Marriott
Australai

[Brucepts]

Yes the 3.490 is 660@16

I assume you are talking about ed's spreadsheet?

[jfholm]

hello bruce the plates I bought from you are a 3.490 and its marked 16"/600

should this be 3.490 16"/660 This works out correctly to the spread sheet.

The other is a 300 28" and measures 2.046 and calculates correctly to the spreed sheet.

The formula at the bottom where I place the flow required and it calculates the diameter , I dont thing I undersatand as I cant get that to match up.

I cant say enough about hoe good this forum is. We have our 12 motor bench running now and are just getting ti the final stages.

Michael Marriott
Australai

I don't know Bruce's ability to get to a computer right now, but I ran it in the spread sheet that Ed from the forum had done. At 16" H2O I show an orifice with a diameter of 3.490" with a cd of .62 should be 660 cfm. I get the same thing you get.

John

[ftch]

Yes the down loadable spread sheet from this site. Extremley good.

Still not sure what im doing wrong when entering the desired CFM and it calcs the required diameter . ?

regards Michael

Thanks on the 660 plare. cheers

[jfholm]

Yes the down loadable spread sheet from this site. Extremley good.

Still not sure what im doing wrong when entering the desired CFM and it calcs the required diameter . ?

regards Michael

Thanks on the 660 plare. cheers

It calculates the needed orifice diameter to flow a desired cfm using the test pressure you have entered above. So make sure you have your desired inches of h2o entered above. An orifice will of course flow much more air at a higher test pressure.

[ftch]

Thanks jfholm

I was doing that , hmm and just did it again and it works correctly.... Must have been doing to many things at once and not focussed.

Cheers
All working
Michael Marriott
Australia