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Re: SF Sizes
Posted: Wed Nov 23, 2011 12:55 pm
by Chad Speier
1960FL wrote:Chad,
I know you are probably getting tired of my off the wall posts but I am trying to understand what SF’s intentions were in there design so we have a logical path to follow to a comparative calibration.
First off the Intended (Design) Delta P is most likely 13.37 not 13.4 yes splitting hairs but it equated to .5 CFM. To my earlier point I do not believe anyone makes a 7.015” rise manometer, thus we know you measured it at around 13.4. So the SG of the oil used is 1.91 the rise of the incline must be 7” and thus DP = 7” * 1.91 or 13.37” based on the SF documentation #5 range is 0 to 450 cfm by using the spreadsheet with air density standards a Preasure of 13.37 and orifice ID of 3.059 then to get to 450.0 the CD they designed around will be .6014.
Am I understanding your posts correctly? But again I am not sure where you are getting the 442.2 /442.9 Number you are using in your flow calc? it is my understanding that #5 on the SF 600 is 0 to 450CFM.
I'm getting the 442.2 number off the bench that SF marked #5 hole with.
Re: SF Sizes
Posted: Wed Nov 23, 2011 2:28 pm
by 1960FL
OK!,
I get it now, they build a bench arond a given design spec then when they manufacture it they put some arbitrary number on the front so you calculate your airflow off that not the actual 450CFM potential of the internal orifice.
HMMMMM, so if you buy a bone stock sf600 with no options you will get one with the 442.2 factor on it but if you buy all the options with Flowcom you might get one with a 452.5 factor stamped on it.
Nice.
In case one is wondering here is the specifications.
http://www.superflow.com/Flowbenches/br ... series.pdf
Re: SF Sizes
Posted: Wed Nov 23, 2011 2:33 pm
by blaktopr
So Rick. Where do you think they got the # from? Different CD or guage oil SG? Kinda weird about the under 450 #. Was it built on a Friday or Monday? I don't remember doing calcs off the inclined back in the day with a 44X.XX
Re: SF Sizes
Posted: Wed Nov 23, 2011 2:35 pm
by Chad Speier
I'm thinking out loud here and I'm wondering something.
I have no less than 5 independent flowsheets that show their #5 hole at 450-456 cfm. I also have one here that has it at 444.8 cfm, it's a newer bench, within 5 years.
I wonder if maybe SF hasn't changed the number, lower, because of the discrepancy between a SF600 and SF1020???? Trying to tighten up the difference between the two.
That might hold some water!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Re: SF Sizes
Posted: Wed Nov 23, 2011 2:40 pm
by Brucepts
That's called "Quality Control" on the holes sizes they machine
Each SF has it's own calibration so no two match I have found from the calibrations I have gotten from some people for their SF600's.
Plus 1 . . . for going digital!!
Re: SF Sizes
Posted: Wed Nov 23, 2011 3:30 pm
by 65mustang393
The #5 orifice on my SF600FC says 447.7 on the data card.
Does SF use their calibration plates to ensure every SF bench is matched up to their baseline calibration plates?
The FC has six ranges and all are adjustable, so you can input whatever the cal data for the orifice is.
Re: SF Sizes
Posted: Wed Nov 23, 2011 3:33 pm
by Chad Speier
I need some help with this next test. This doesn't look right.
I have the small well (without the fluid/left side) tee'd and hooked to the top of the extra manometer on the bench. With a head on the bench, I made the depression read 28" with 100% manometer.
Both on #3 and #5 holes, the manometer is reading 3.80.
Is this correct?
Re: SF Sizes
Posted: Wed Nov 23, 2011 3:36 pm
by 65mustang393
Chad Speier wrote:I'm thinking out loud here and I'm wondering something.
I have no less than 5 independent flowsheets that show their #5 hole at 450-456 cfm. I also have one here that has it at 444.8 cfm, it's a newer bench, within 5 years.
I wonder if maybe SF hasn't changed the number, lower, because of the discrepancy between a SF600 and SF1020???? Trying to tighten up the difference between the two.
That might hold some water!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
http://www.speedtalk.com/forum/viewtopi ... a544a8eb0c
I was sent this.
"Pass the word but please dont tell anyone you heard it from me."
"The Superflow 1020 bench has problems with turbulence entering the orifice plate at higher air speeds. This is why the 1020 number and the SF600 numbers are the same or close tot eh same up to about .500 lift then the 1020 shows the head to flow less from there on up. The more air you flow, the more discrepancy there is between the benches."
So please don't ask who sent this to me.
Stan
Little thread on speedtalk that shows maybe a little problem with SF1020... Anyone on here have connections with SF to maybe verify?
Re: SF Sizes
Posted: Wed Nov 23, 2011 3:43 pm
by 65mustang393
Chad Speier wrote:I need some help with this next test. This doesn't look right.
I have the small well (without the fluid/left side) tee'd and hooked to the top of the extra manometer on the bench. With a head on the bench, I made the depression read 28" with 100% manometer.
Both on #3 and #5 holes, the manometer is reading 3.80.
Is this correct?
Is this because the SF benches are rated for 25" of water?
Re: SF Sizes
Posted: Wed Nov 23, 2011 3:45 pm
by jfholm
I have heard the same issue