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Duct Construction and Uses
Discussion in fabricating and use of products that move air including spiral pipe, duct board and typical sheet metal work.
       


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  #1  
Old 12-17-2014, 11:33 AM
Bradleyc1982 Bradleyc1982 is offline
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Default Duct manufacture

please help..at the moment when making elbows, straight square duct (and round) and transitions I put a 5/8" flange on and pop rivet them together. I'm looking to purchase a Pittsburgh seam and lock forming machine, was wondering if the Pittsburgh seam would lock all pieces together?. I know that for the elbows and straight sections it would be fine, but was wondering if that was the seam of choice for transitions and offsets?? Is the Pittsburgh seam the best for that or should I look at something else?.? thanking you in advance Bradley
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Old 12-17-2014, 05:05 PM
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Definitely the seam of choice for us.
The only items we rivet are the smaller ones that we know the lock former will either spit out, or worse yet, get jammed up in the machine.
Highly recommended.
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Old 12-17-2014, 05:25 PM
wmckane wmckane is offline
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Flange if you have to but a Pittsburgh seam is always preferable. And it's better than snap lock (prefab duct) too because it usually stays where you put it. Also a much tighter seal, which means less sealing for you. You'll be glad you did!
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Old 12-17-2014, 05:33 PM
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Snap lock just needs a screw to keep it in place.
Pittsburgh seam will travel sometimes.
Poke it with an automatic punch on the hammered side at one end.
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Old 12-17-2014, 05:42 PM
wmckane wmckane is offline
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Yep. I think the weakest use for snap lock is on radius elbows---almost always have trouble with the fit, where a properly laid out pittsburgh will go together with minimal fuss.
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Old 12-18-2014, 12:45 AM
Bradleyc1982 Bradleyc1982 is offline
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Ok Pittsburgh it is then !! Can I get one machine to do flanging and seaming or wil i need two machines? I have been looking at this (not sure on quality though). Think it is available with a flanging tool for round elbows aswel? http://www.wnealservices.com/acatalo...llformers.html How small a piece would you pop rivet together?? Thanks for the replies
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Old 12-18-2014, 05:25 PM
wmckane wmckane is offline
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We used to use a 10 foot brake to form the flange; ours were 1/4". There was a stationary Lockformer machine that ran a Pittsburgh on one side and several types of flanges on the other---this was mainly used for the doubled right angle flange with a tab below that you find on take-off fittings. Another machine turned edges on radius pieces. So we would edge the cheeks of an elbow on that one and run the heel and throat through the Pittsburgh. Those two would be formed on a slip roll and then everything put together.

Your machine looks like it does everything except the take-off flange, plus runs drive cleats. Sounds good but I think I'd want to see one and use it a bit if possible. This is a big purchase. I also think I would not go with a portable version.
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Old 12-19-2014, 12:08 AM
Bradleyc1982 Bradleyc1982 is offline
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Ok great..I'm with you on all of that except the take off flange? What is that? I would like to use the machine also, not the portable though! I think the distributor has demo machines, although not sure if that is sufficient to really get to know a machine?!,.
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Old 12-19-2014, 05:32 PM
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Quote:
Originally Posted by Bradleyc1982 View Post
How small a piece would you pop rivet together??
Anything less than 4 inches is difficult to control through the lock former.
It wants to bind up on the last guide roller.
It's hit or miss.
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Old 12-19-2014, 05:52 PM
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Quote:
Originally Posted by wmckane View Post
doubled right angle flange with a tab below that you find on take-off fittings.
We call this a clinch edge or fish lock.
Many hours spent bending them up manually.
Now I have slaves that do that for me.
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