DC Piping

Al killian

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Floydada, Tx
Spiral pipe? I am not sure exactly where to find it or what it really is. Is is something that can be found in a HVAC supply house? I am ready to step up from useing a short hose and going from machine to machine with the DC. Sewer pipe in larger size can only found in the cities(hour plus drive on way):( or going thru local plumbers that want way to much for it. So I am looking for alternatives to PVC.
 
Suppliers to the HVAC firms is one place.

I know Lindab is a company that makes them. I think JET sells them as well.

They're out there. If you go into many commercial/industrial establishments, it is what they use often for their forced air ducting or exaust.

I used 4 inch PVC for my DC collection system and I did not understand what was really meant by "Static Pressure" of plastic piping vs. metal piping. Thankfully I have a small shop with short runs, as I realize now that static pressure is like having the inside walls of the ducts wet insofar as what they could pull vs the same size in metal spiral duct.

The other advantage is there should not be grounding issues with metal pipe, whereas plastic, although they say that in a home hobbiest using less than 5HP DC there should be no concern, I don't want to be the one in a million to find out otherwise, so I grounded my piping inside and out.

The cost for me of the PVC vs Spiral was $600 vs $$750. I honestly decided on PVC for simplicity of implementation and the fact I could run down to Home Depot and get joints and connectors as I went along, rather than have to deal with returning unused components or acquiring additional components at greater expense and delay using spiral.

Here in Canada, the only source I found within reasonable distance of the grreater Toronto area were all wholesalers and have a list price for suckers and a contractors price which is 40 to 60% less if you can get chummy with them and get them to agree to sell it to you at that price. I actually did get one of them to agree to 50%-60% discount on the initial order.

Do your homework as to what you need and have a list of what you want to buy. Lee Valley has an excellent self cleaning metal blast gate that was cheaper than the non-self-cleaning ones sold anywhere else I found which is what I used for mine.

Good Luck...Kevin
 
I'm on the exact same quest at the moment and frankly I'm finding the duct research harder than the time I spent researching the cyclone DC. I'm heavily leaning toward going with the spiral duct but who knows at this point. One thing I've noticed on Bill Pentz site is that the type with laser welded seams is much better than the stuff a lot of companies make so I've been watching for this on my web-surfing. Here's a excerpt from Bill Pentz' site:

Here are the Hazen/Williams friction factors for various duct types (a higher C number is better).

Corrugated steel duct= 60
Spiral Duct = 90-100
Laser Welded Steel Duct = 110-125
3-PVC Duct = 146

Bill's site also had a recommendation and link to these guys:
http://www.ductincorporated.com/companyinfo.htm

And these also seem to be using laser welded duct
http://www.nordfab.com/pipe.cfm
http://www.monroemetal.com/products/product_category.cfm?category_id=1

Haven't investigated the prices yet from any of these, but I hear the Nordfab stuff is pretty pricey.
 
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I looked at home depot for 6" pvc, but the dont not carry it. At this point if I have to order it it looks like it will be close to the same price. Laser welded pipe from what I have seen is way to much funds, at least till I win the lottery.:D :rofl: . Thanks for the input. When I do decide on a final setup pics will be posted.
 
Al, on the 6" PVC, you won't find it at HD or Lowes. I've heard from some that a few Menards carry it. If you are interested in using it, you need to find a wholesale plumbing supply house. Ask a couple plumbers in your area where they buy their supplies. I found a couple places that could get it, and one that normally had it but was out, and one that had it in stock, but didn't know what it was called! Ask for thin wall gravity fed sewer and drain pipe, 6". The ATSM numbers didn't seem to make much sense to anyone I talked to. I bought 2 10' lengths at 1.86 per foot, then the last 3 they sold to me for almost half that! It was 10.11 each including tax (8.25%). McMaster Carr has the best price for the 6/6/6 wyes, and the 45 els. If you use any 4", again better priced there. I got 6/6/4 wyes at Lowes for just under 19.00 each. Go figure, they have some fittings, but no pipe! Maybe the same fittings fit on the green S&D pipe that they carry, never tried to fit it together. I got my 6" flex from Woodworker's Supply. Best price I found. Waiting on the 4" to come off back order. With a little use of a hair dryer, it fits on the 6" PVC nice and tight. And for those of you with MiniMax and maybe other, dust inlets that are metric...The 4 inch thin wall PVC is a tight tight fit over that, then you can plumb with the pipe and fittings! I didn't even feel that I needed to seal the joint, but I did silicone the edge anyway.:thumb: I'm guessing the other units have the same outlet for DC hookup that my E16 has. Hope this helps!. Jim.
 
I was going to say what Jim said. So rather than repeat it I will just second it, find a plumbing supply house.

I have never worked with spiral duct but I would imagine that PVC would be much easier to work with and simpler to make changes to in the future. Once I finally do get to do mine that is what I am going with.
 
Any decent sized sheet metal shop fabs spiral ducting. Yellow pages, plumbing heating and air conditioning.
 
Al, I'm in NJ. I use Dunphy and Associates Supply Co. (Dasco). They are in Edison and Whippany. And I'd definitely recommend the spiral pipe route, I love mine.
 
I just talked to my freind how does HVAC work. He says when I am ready to install the spiral pipe he will get it for me at his cost.:thumb: So I think this will be the route taken. Now I have one other option that someone else around here has in there small shop. He is using stove pipe and has had no problems over the last ten years. I am just wondering if this will hold up on long runs. Next summer I will be moving into my drem shop ( 30x60) with 13' ceilings. All the walls are coverd w/tounge and grove red oak. When I do move in I am going to build Bill Pentz cyclone and I do not want the pipe to collapes due to suction. This the main reason for doing so much asking and searching.
 
al, "stove pipe" can run anywhere from 20 gauge to past 16 gauge, be stainless or mild steel ect.......if you have a soure for spiral pipe and fittings that won`t break the bank i`d go that route.......tod
 
Al, that stove pipe you mentioned gave me an idea.

I remember years ago installing a pre fab fireplace and using 12" OD flue that had an inside dimention of 8" ID.

I have a Pentz cyclone I built and want to install a muffler at the filter side. I am thinking a section of that flue might just do the trick. It is packed with glass fiber as a fireretardant, maybe a good sound blanket as well?

If I remember correctly it was pretty affordable and came in 24 or 36 inch sections.

Just a thought.
 
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