PTS Flowbench Forum

An introductory to PTS Orifice plates, does not get into the math behind plates.

Great video! Very professionally done. I would suggest this video as a must watch video. btw I would like to see more than just your chin

John

I tried to keep the video "tight" as the backdrop only covers so much of my mess in the shop

I have a wider backdrop for future videos to come. Cleaning and organizing the shop as we speak so I have a larger studio!

While editing this video I found I shot all of it using SP instead of HD DUH! Working on a new audio setup so I'm not using the camera's audio which sucks! Hence the reason I needed to be close to the camera . . . don't focus on my chin anyways, maybe it was a distraction to the video content?

Video is shot unscripted, I'll try and work on that in future shoots.

I am editing another one shot the same day on motor controls, should get that one up later this weekend.

Bruce,
I thought it was a great video and very well done. Professional and informative. Keep these coming as it really helps the new guys. It sure helps take the mystery out of flow benches. I think that big blue wanted it to be a mystery so they could make so much money from building benches. I have worked with a lot of benches in the years past and I find your design is by far the best. When people see how easy it really is to build a bench from your plans they should be beating your door down to buy some. Your products are excellent.

Very well done Bruce, keep the videos coming.
The plain uncluttered background is most appropiate, and the dialog very clear and easy to understand.
A lot of thought has gone into this, and the result is excellent.

Wow! I had not seen this video congratulations Bruce.
Too bad it only understand part Flow Bench ... lol

great stuff Bruce...

Okay so I'm new to this web site but there are some things I don't understand.

First the 16" differential is for internal, but to actually measure flow across what ever you are measuring, probably a head, wouldn't the differential vary based on the flow? Hence the formulas and spreadsheets elsewhere on this website?

Despite the norm being 28" of water column being the standard, if you wanted to drop that to 16" wouldn't the 16" number still be valid on the bench top?

Eeyore wrote:Okay so I'm new to this web site but there are some things I don't understand.

First the 16" differential is for internal, but to actually measure flow across what ever you are measuring, probably a head, wouldn't the differential vary based on the flow? Hence the formulas and spreadsheets elsewhere on this website?

Despite the norm being 28" of water column being the standard, if you wanted to drop that to 16" wouldn't the 16" number still be valid on the bench top?

You can use any differential pressure (DP) you would like, 16" is used on the PTS Digital manometer, if you build water gauges you can set them up for any DP or rise. Your test pressure can be any pressure you would like to test at also, for the most part 28" is a good standard.

The plate is machined to work with the DP so for example a 300cfm @16" plate would allow you to test from 0-300 CFM no matter what you are testing on top of the flowbench at what ever static pressure you use as long as it does not flow more than 300cfm at the test pressure. You are still creating 0 to 16" of DP across the orifice plate, CFM is calculated from the DP across the internal orifice plate 0 would be 0 cfm and 16" would be 300 cfm and any DP between those two would calculate out to a cfm between 0 and 300cfm.

Take a look at the Flowbench 101 post on the forum here which might explain it a tad better than I can.

Yeah, I've read the 101 and a lot of other threads on here. I just wanted to make sure I understood the 0-16" and in your example 0-300 cfm. It seams that the value is always given as an absolute, as in 300 cfm and 16". I wanted to make sure I was correct that in use it is a variable and that is what the DM or water manometer is measuring. I got it, that's what I thought, I just didn't read it that way. I need to make another longer post, but this is probably the wrong area. Thanks Bruce!

Oh one more thought. I think I read somewhere on here that you were thinking of offering a DM that worked at a lower differential (less than 16"), is that still a possibility? Just seems it would lower the vacuum motor demands.

Thanks again!