Author Topic: Flat Oval  (Read 2673 times)

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Offline DDI LtdTopic starter

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Re: Flat Oval
« Reply #15 on: Sep 26, 2005, 11:58:39 AM »
well... erm.

That can be one of the points of having this, so when you jiggling with your f/o size, it tells you what the circ equiv is ie.. 248.9 dia. looking at this, will tell you that this size is a male 250 dia equiv without having to look at anything. And sometimes we do not use off the shelf sizes, as there are all the other sizes inbetween which are all possible to manufactor.

i just guessed it would be something like the angle shown on a taper. the same kinda thing for the circ equiv, you cant edit it, just view it.
Gary Hussey - Ductwork Design & Installation Ltd

Offline Danlux

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Re: Flat Oval
« Reply #16 on: Sep 26, 2005, 01:25:27 PM »
I see
Scripting ain't for me............. I'm rubbish! :)

Online Don

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Re: Flat Oval
« Reply #17 on: Apr 11, 2018, 03:12:46 PM »
I would like to re-open this thread because I am fishing for some information.

We have a job that we are currently looking to compare the price for manufacture in flat oval instead of rectangular (should work out cheaper) I think. As this is only a comparison at this stage, I've used flat oval sizes that are formed from the circular design equivalent of some of the rectangular sizes on the list of ductwork I have. This should be good enough for the purpose of putting a price comparison together.

However, if we wanted to go along the route of swapping out rectangular for flat oval I would need to make sure that all the "science" is covered in respect of making ANY allowances for the shape change i.e. are there any losses to incorporate for friction e.t.c

I'm not a designer so this is so far out of my league. I've looked on line for some guidance, but have found conflicting information, some showing my best guess to be undersized - some say oversized.

Has anybody got a conversion tool for this that they have used and consider to be ok? Or any information, formulas etc, that would enable me to build my own conversion tool would be very welcome.  :) 

Oh and sorry for the long explanation.  ;D

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Offline VirtualPilot

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Re: Flat Oval
« Reply #18 on: Apr 12, 2018, 02:18:20 PM »
I would like to re-open this thread because I am fishing for some information.

We have a job that we are currently looking to compare the price for manufacture in flat oval instead of rectangular (should work out cheaper) I think. As this is only a comparison at this stage, I've used flat oval sizes that are formed from the circular design equivalent of some of the rectangular sizes on the list of ductwork I have. This should be good enough for the purpose of putting a price comparison together.

However, if we wanted to go along the route of swapping out rectangular for flat oval I would need to make sure that all the "science" is covered in respect of making ANY allowances for the shape change i.e. are there any losses to incorporate for friction e.t.c

I'm not a designer so this is so far out of my league. I've looked on line for some guidance, but have found conflicting information, some showing my best guess to be undersized - some say oversized.

Has anybody got a conversion tool for this that they have used and consider to be ok? Or any information, formulas etc, that would enable me to build my own conversion tool would be very welcome.  :) 

Oh and sorry for the long explanation.  ;D

Yes, SEMCO has a little program that calculates Oval based on a rectangular size... (spoke too soon, seems like they took it down)

Eastern shows one calculator, check here...   http://www.easternsheetmetal.com/Tools/Equivalent-Round-Duct-Calc-App

But be aware that NOT all sizes are manufacture-able in oval, it all depends on the round duct and the DIE used to stretch it with, so, for correct duct sizes possible with Oval, use our chart, if you have questions on the chart shoot me message.
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Online Don

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Re: Flat Oval
« Reply #19 on: Apr 12, 2018, 02:47:03 PM »
Thanks for the info VP. I've seen the Eastern calculator, I downloaded it yesterday but at first I discounted it as it is written using Imperial dimensions.

We manufacture our own flat oval in set sizes from 320 x 76 to 1885 x 508 so I will need to find the best design equivalent closest to one of our sizes keeping the depth no larger than the rectangular depth.

The Eastern excel tool was password protected, but I've managed to get past that  :-X so now I can see their formulas it might help me to sort one out in metric using our range of flat oval sizes. I was just hoping to save some time and find a metric input tool. Looks like I will have to go down the longer route instead. 
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Offline VirtualPilot

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Re: Flat Oval
« Reply #20 on: Apr 13, 2018, 01:52:27 PM »
Thanks for the info VP. I've seen the Eastern calculator, I downloaded it yesterday but at first I discounted it as it is written using Imperial dimensions.

We manufacture our own flat oval in set sizes from 320 x 76 to 1885 x 508 so I will need to find the best design equivalent closest to one of our sizes keeping the depth no larger than the rectangular depth.

The Eastern excel tool was password protected, but I've managed to get past that  :-X so now I can see their formulas it might help me to sort one out in metric using our range of flat oval sizes. I was just hoping to save some time and find a metric input tool. Looks like I will have to go down the longer route instead.

Seen this one? at the bottom of the inputs it can be changed to Metric...

http://efficientcomfort.net/asp/AllDuct_Web/AllDuct_Web.asp
Santos Cedeno
CAD/BIM Mgr - DIXIE Metal Products
Adesk Design Suite 2016 - FAB CAD - FAB CAM - FAB EST / SP 4
DELL T-5810 Intel Xeon 3.50Mhz - 16Gig RAM - 4Gig AMD FirePro 5100 - W10/64 - 1T HD