PTS Flowbench Forum

You all sleeping???

I posted data and no discussion???

Did I make you all speechless with what I posted???

What can we say with test results like that!

Oh, 'I use Bruce's orifice plates to calibrate my flowbench!'

Ray

Bruce,
That effort was much appreciated! What I want to do also is hook my vertical manometer up to test the actual Delta p of the orifice inside the bench at 100%. What I want to do is put my head on the bench and then test each orifice inside the bench. I will adjust the valve to an opening lift until it reads 100% on my inclined at a set test pressure and see where the vertical reads. I will try to do this to see if the Delta P stays the same with each orifice also. That would be an interesting test.

John

jfholm wrote:Bruce,
That effort was much appreciated!
John

Oh the effort was under taken for Rick,Tony, and myself's understanding of what we actually designed and built . . . I'm just sharing it with you all

I spent probably the better part of 2 weeks trying to get a better understanding of the digital manometer project's capabilities beyond what we already know or thought we knew. But the more we learn and understand the more we can think of other things! Personally, I think we just scratched the surface on what we can do with this product! For a couple of guys who did this project via emails, phone calls and a few personal visits still makes me say "hummm, the damn thing works quite well".

One of my projects was to run the DM in conjunction with water gages while testing plates this verifies the sensors follow along with the water gages and sets my calibration number. At one point in my testing I was using a 1" inclined manometer to look at the low cfm numbers. It was also connected to a commercial hand held digital manometer for the "hell of it".

You will find if you do enough orifice plate testing there comes some point in time when you say "ok what more can I achieve?" And you just kinda start going in circles!

We are still learning . . . .

I want to do also is hook my vertical manometer up to test the actual Delta p

John I think this would be well served if you used two water gauges one on the depression side and one on the motor side and did the actual math rather than use a u tube and only measure the DP. You may ask why but i bet we could gain some motor knowledge from testing like this.

As for Bruce's testing and some playing around here in the lab/office I leaned that the sensitivity of the PTS DM is enough that you could measure a Nats Phart. The issue is making sure the end user does not lose the perspective of what the devise is for and uses it in the most accurate manor. I believe based on your motor choices you will need a minimum of 3 internal plates and would be best served with 4 or 5 that fit your motor combination and testing needs.

I am currently working on an update to FlowSoft to allow multiple configurations so it will be easy to change between plates and there given calibration settings both intake and exhaust.

25 to 600 on one plate is a grate thing in the lab but i think you are asking for trouble trying to do this in real world testing.

Just some thoughts.

Rick

Rick,
I think you are correct and am planning on using 4 to 5 orifices when I flow even if the digital manometer may cover the range.

John

jfholm wrote:Rick,
I think you are correct and am planning on using 4 to 5 orifices when I flow even if the digital manometer may cover the range. John

Most of my testing on the "big bench" very closely mirrors the testing posted above.

We switch between ranges as we find that there IS a "sweet spot" in every orifice plate made that will give you almost linear results.

Finding out if a Tested part actually did change with a modification is easily worth the cost of multiple orifice plates.

JMO

Tom Vaught

There are some variation in my bench with (2) 400 cfm plates when calibrated for 350cfm. But its at the lower numbers, around +/-5 cfm. However, if all your R&D efforts are tested in that manner then you will still see the gains or losses for your own notes.

It seems to me, that if you have built a monster flow bench that can flow perhaps 600 CFM+ but you are doing a particular project that involves some small engine testing, you fit an orifice plate with a flow range appropriate for the job.

Anyhow, the whole thing has worked out extremely well for us all, and the hardware seems to be quite stable with temperature, and the repeatability is good too, which were my main concerns at the design stage.
As far as I know, there have been no equipment reliability issues either, which is also very satisfying.

It is interesting that as time goes on, further testing and experimentation is showing how good this system really is, rather than exposing any weaknesses.

Tony. My DM has been through pretty harsh "conditions". Its outside in the garage for a few years, from 0*F to 100*F and different humidities. Still works the same. And thats how the bench is set. Calibrated close to the range of the work. Good job.