I just checked my bench, does this look right

[JRM]

Hopefully this is the final insanity lol.
I was abol to borrow a set of test plates from my equipment supplier. (Jamison equipment)
Here are the results I came up with. keep in mind that these plates have been checked on a fiew SF benches so I am using the asumption that they are accurate, I've noticed the numbers varied between test plates so im a little confused.
the formula i used to figure my disk was. 13.55*ori diameter SQRT * SQRT28
my plate thickness is .050 using a sharp edge

Using 600 cfm test plate tested @28" a 2.5" hole

4.193 hole (1265 cfm) 49% @ 28"

3.625 hole (945 cfm) 74% @28"

2.550 hole (467) 92@ @28"

2- 1.590 holes (362) 77% @28"

1.770 hole (225) 72% @28"

1.320 hole (125 cfm) 71% @ 28"



Using 450 cfm test plate with 1.897 hole

4.193 hole (1265 cfm) 27% @ 32"

3.625 hole (945 cfm) 41% @ 28

2.550 hole (467) 96% @28

2- 1.590 holes (362) 89% @ 28

1.770 hole (225) 80% @ 28

1.320 hole (125 cfm) 70% @ 28

.930 hole (62 cfm) 75% @ 28


Using 300 cfm plate 1.746 hole

4.193 hole (1265 cfm) 20% @ 34"

3.625 hole (945 cfm) 34% @34"

2.550 hole (467) 95% @29

2- 1.590 holes (362) 89% @ 28

1.770 hole (225) 79% @ 28

1.320 hole (125 cfm) 74% @ 28"

.930 hole (62 cfm) 69% @28

Using 1.200 150 cfm test plate

.930 hole (62 cfm) 55% @ 28

1.320 hole (125 cfm)77 % @ 28

using .805 test plate

.930 hole (62 cfm) 52 % @ 28

[JRM]

forgot to add im using the red fluid in the meters.

[larrycavan]

JRM

I'm not understanding how you tested.

Let's take the 600CFM calibration plate by itself. If, what you mean is that calibration plate flows 600CFM @28" on a Superflow, and the results you got on your bench was 49% of a range you are figuring to be 1265CFM, then the range would calibrate out to be about 1225 [.49 * 1225 = 600.25] I would consider that to be quite normal variance from the formula calculated value of the range. [Coefficient of Discharge works out to .622]

Now, moving on in the same line of thought, the 945 range calibrates to 812 [.74 * 812 = 600.88] [Coefficient of Discharge .534] [the other hole is more efficient - nothing to worry about]

From that point on down, that thinking goes right out the window because you should be well above maxed out on the rest of the ranges [467 - 362....etc.] They are all less than 600CFM. What am I missing here?

On a more certain note, the red guage oil will affect your readings because it's lighter than water and will travel aprox. 1.2 times further on the scale at any given pressure. If you have it in both manometers, you need to adjust your scales for it.

If not done, 28" on the vertical is actually closer to 22.4" and 49% on the inclined is closer to 39.2%.

[JRM]

Hopefully I can explain better.
the test plates have been flowed on a fiew different super flow benches. I put the hole diameter as well as the verified numbers for each test plate.

I did some more research tonight and if i am understanding correctly if my ori plate hole flows less then the test plate all my numbers will be off. Does that make sence, the way it was explained is use a verified test plate that is = or less then the machined ori plate to get accurate test numbers.
If I am understanding correctly if the ori plate flows mathmatically (sp) more then 600 cfm @ 28 use a 600 cfm test plate. If it flows less then 600cfm use a smaller test plate.
On a plus note the manometer readings are rock steady :;):

[larrycavan]

[JRM]

Larry,
Thanks for the help. The test plates I was abol to borrow are 600 cfm, 450, 300, 150,125,62. I just talked with the guy who let me borrow them and he said all of the test plates have been checked on diferent superflow benches @ 28" . I have to call him back later to see if i can borrow them for a little bit longer to rerun the cal tests doing what you suggested.
on the manometers the incline is a dwyer durablock if i rhember correctly its a 246 model. It goes from 0-100% the scale is 20" long. the virt meter is also a dwyer that goes to 36".

[larrycavan]

[larrycavan]

John,

Here's a speradsheet for you to use.

[JRM]

Thank you for all the help
John