# Using ASTM 3034 - SDR35 - PVC Piping in Clearvue DC System



## MJCD (Nov 28, 2011)

I'm upgrading my DC system to a Clearvue CV1800, and am researching Ducting alternatives.

I've read a great deal about thin-wall (ASTM 2729) white PVC piping - it's lightweight, evidently in-expensive, and … virtually impossible to find - I'm in the Annapolis, MD area, and large plumbing supply houses won't touch the stuff.

On the large-scale side is Schedule 40 PVC, that in the 6" diameter version is both heavy and expensive, as well as a special order from the Big Box stores.

Several Plumbing Supply professionals are recommending the interim ASTM 3034, or SDR 35 by another name, piping. While this sounds good, I can't find comparative statistics to determine if the slightly thicker walling equates to a stronger pipe - there's nothing that I can find which says the products are chemically, mechanically equivalent, with the only difference being additional thickness.

Has anyone used the ASTM 3034 (SDR 35) material in their DC system, and if so, can you provide commentary on how it's handled the job?

Thanks for your input.
MJCD


----------



## marcuscraft (Nov 14, 2012)

Will the PVC build up more static electricity than other pipe? My only thought when I read this was to make sure you have a grounding wire in place.


----------



## MJCD (Nov 28, 2011)

Marcus:

Thanks for the response - fortunately, my electrical panel ground is close-at-hand, and I'll ground the ducting to it.

MJCD


----------



## AandCstyle (Mar 21, 2012)

I once read that grounding PVC is pointless because plastic is an insulator so any grounding is only effective VERY close to a ground leaving the remainder unaffected. I have about 80 feet of PVC in my shop with metal blast gates and never get any static shocks from them. FWIW


----------



## paulnwa (May 22, 2011)

I live on the other coast of the country from where you are, so I have no idea what sources you might have for the ASTM D2729 thin wall PVC piping and fittings. That said I found these contacts as possible sources in your area, tho I don't know how far away you are from any of these:

http://www.hellotrade.com/hardmetal-underground-supply/contact.html#
http://www.macraesbluebook.com/search/product_company_list.cfm?prod_code=3107250&region=Maryland-MD
http://www.mcmaster.com/#pvc-pipe-fittings/=psr1o3

I don't know how the specifications for the ASTM D2729 and ASTM D3034 compare, but I suspect the latter is a little heavier wall thickness. I would think either would work for your application. I have a small shop plumbed with 6" thin wall D2729 PVC for my 3HP DC. A lot of folks who have ClearVue cyclones have used the 6" thin wall PVC ducting with great success.

Another possibility might be to contact either irrigation supply companies, or companies that install septic tank systems.

BTW, I find that static electricity build up on the PVC duct surface due to the high airflows only occurs here in the Seattle, WA area when the air is cold and the humidity is low. Annoying sometimes, but not dangerous and definitely not an explosion hazard as some folks would lead you to believe. Some folks have wrapped a grounded bare copper wire around the ducts they may come in contact with.

Hope you find what you are looking for.


----------



## wapakfred (Jul 29, 2011)

I have a mix of both on my system. I started with the thinwall (2729) and then I moved and needed some more, but couldn't find it. Menard's carried the 3034, and actually had it for about the same price I paid for the 2729 so I bought it. Performance wise, you will not notice a difference, if there is one it would take laboratory instruments to measure it. The thin wall fittings still fit. Where you will notice the difference is in the weight, and maybe the cost. My system is hung from the ceiling, and I did it as a one man job. I doubt I could have done that with the 3034, it's just a lot more awkward to deal with due to the weight. As for the cost, the thinwall I bought was quite a few years ago, at $17 per 10' stick from a local lumber chain not known for discount prices. The 3034 I got from Menard's for about $20 for a 10' stick. Usually in rural areas you can find the thinwall, it's used a lot on farms. But i live in a rural area, and it's still tough. If you have a Hughes Supply nearby, try them.


----------



## MJCD (Nov 28, 2011)

Many Thanks for the considered responses. From what I've researched, the 2729 has a regional availability, with Menards being one of the few big-box to have a supply, or have-supplied at one time. I've asked my contact at Clearvue for their opinion - Fred, my guess is they'll be no issue. Previously, I had the shop piped with Schedule 40 (4"), so I could do the weight - not sure I could do this with 6".

The Northeastern US temperatures fluctuates between 95 degrees and 15 degrees, and the somewhat thicker wall makes sense, on many fronts.

I'll update this Forum Post when Clearvue responds. Thanks, again.
MJCD


----------



## paulnwa (May 22, 2011)

If you go with the 6" thin wall PVC, i highly recommend the PETG plastic duct hangers and the 6" blast gates that are sold by ClearVue Cyclones. I just finished helping a friend install his 3HP cyclone system using these products, and found they are easy to use and work extremely well. The hangers fit the ducting snugly and space the duct about 2" or so from the wall/ceiling, which was great clearance for the conduit we had installed on the ceiling for the overhead lighting.


----------



## MJCD (Nov 28, 2011)

Paul, Others-

I received a fairly emphatic "NO" from Clearvue, on the SDR 35; with an equally emphatic "use the 2729"-so, I will.

The closest supplier is Cresline in Mechanicsburg, PA - a long driving-distance for me, but it's better than paying shipping for the 10' lengths, and boxes of fittings.

With this, Paul, I'll look at Clearvue's blast gates - I was going to make them; however, it may just serve me better to purchase them from the source.

MJCD


----------



## khowarte (Mar 26, 2011)

I used the 2729 pipe that I found at a local plumbing supply house on my Clearview. The 2729 pipe has 28.27 sq in of area versus the SD35 only has 27.11 sq in which is a 4.1% reduction in cross section. To mount it I used 6" ss band clamps from Menards. I drilled a hole for a drywall screw at a location on the clamp that would put the clamp screw in a good location to tighten it. I used 2×4s fastened to the concrete wall and ceiling joist. I tried some tie wraps and they are hard to get tight. Menards had most of the thin wall fittings I needed. Used furnace 6" to 4" reducers at the equipment. Cut slots with the bandsaw in the 2729 to get 6" hose on and used band clamps to secure it.


----------



## JJohnston (May 22, 2009)

I used nothing but SDR 35 on my Clearvue system. I couldn't get the super-thin wall locally. It works fine. Weight is not an issue. I've got mine held up with small screw eyes and soft steel wire.


----------



## shawnmasterson (Jan 24, 2013)

I used sdr35 on mine. the stuff I got was 14' lengths and has rubber slip gaskets on the end bells and fittings. The cost was minimal compared to the cost of glue fittings. I went this route thinking it would be sealed better. I would not recommend it. the fittings were very hard to slide together, and I think they will come apart even harder.


----------



## wapakfred (Jul 29, 2011)

Did CV say why they were so adamantly opposed to the heavier pipe? That 4% reduction in cross section doesn't seem like it would make that much difference.


----------



## Grandpa (Jan 28, 2011)

the fittings were very hard to slide together
Did you try using dish detergent for a lubricant on the rubber gaskets? This usually makes rubber components slick and it will not normally harm most gaskets. When it dries it might be even more difficult to take apart but not impossible.


----------



## MJCD (Nov 28, 2011)

Fred, ...:

The comment from Clearvue is that SDR35 is "Thicker and Heavier". I interpret this as resulting in the smaller ID. From an airflow perspective the different may be only 3.1% (it's the % change in the square of the ID: 6.175 (38.1) vs. 6.095 (36.9)) - I'm not sure about this, but it's between 4% and 3% - not much, for the wear & tear I've gone through to find the 2729).

I'll trust Clearvue's comment - from their perspective the SDR 35 is more expensive, heavier to install, and results in lower CFM & higher Static Pressure. Availability becomes my issue - no disrespect to Clearvue - they have been GREAT in addressing my questions (nice people to deal with).

The SDR35 comes in both Gasketed and Solvent Weld (attachment differences) - my plumber strongly recommends against the gasketed - once it's together, nothing gets it apart; and the tolerances are such that I shouldn't have to 'solvent weld' the fittings.

My homework is near complete: if the 2729 is available locally (I'll find out tomorrow, Monday), my plumber can purchase it - it will be my hands-down selection. If not available locally, I'll have to pay List Price and drive 225 miles (round trip) to get it; tipping the decision to the 3034.

Everyone, thanks for the input.
MJCD


----------



## shipwright (Sep 27, 2010)

Have you looked at PVC fitting prices? Check this out before you spend too much.


----------



## paulnwa (May 22, 2011)

I would avoid using the PVC with gasketed ends. If the D3034 is available with the socket ends, that would be my choice if the thin wall D2729 was not available. The OD/ID fit of the PVC ducting to the fittings or to the bell ends on the duct pieces is very good. Leakage has never been a problem with any of the systems I have put together without caulking, solvent welding, or even taping of the joints. 
In my opinion, the slight performance hit you will take for the 3-4% reduction in area if you have to use the D3034 ducting should not be a serious problem with a ClearVue cyclone unless you have a very large shop with lots of long runs. Unfortunately, sometimes when we assemble a DC duct system, we have to make compromises that depart from the ideal-but in my opinion, that is not any worse than having to add a wye or an ell or use a longer length of flex hose than we wanted to just to clear some obstruction or accommodate a more efficient tool grouping.

BTW, if you haven't seen them, the fan curves for the Clearvue cyclone line can be found here: 
"http://www.clearvuecyclones.com/Bullentin/showthread.php?t=1383"

As you can see from the fan curves, this line of cyclones has outstanding performance. I installed one in my previous shop and really hated to leave it when I moved into a different house having a very tiny shop with very limited ceiling height.


----------



## MJCD (Nov 28, 2011)

Paul:

Thanks, it looks like I'll go the 3034 route: I want this done. The CV1800 (which I've upgraded, with the Clearvue Christmas program - a larger impeller (16" vs 15") - is somewhat overkill for my shop. However, I like to do things once, and move-on (Focus, Finish, Move-on is a long-time favorite saying)...

Are the Clearvue Blast Gates compatible with the 3034? I'm on the fence about making them; however, I'm backed-up on projects, and need to get working on the backlog.

Everyone, thanks.
MJCD


----------



## JJohnston (May 22, 2009)

I tried to put together one of the gasketed joints, and gave up. I cut off the bell and went with a plain old coupler. Clearvue blast gates fit fine. Outside diameter of both types of thin wall pipe is the same.


----------



## MJCD (Nov 28, 2011)

Shipwright:

Thanks for the link - and the consideration.

Tempting …, very tempting - I know where my connections are: I'm ducting to generalized locations, then using flex hose to get to whatever equipment I'm using - mine is a limited, mobile shop. The pvc connectors will cost the lionshare of the ducting. The question is whether I have the downtime, at my skill level, to a decent job on what you've done - I might have the patience.

MJCD


----------



## paulnwa (May 22, 2011)

As someone mentioned, the OD of the PVC ducting is the same for the D2729 and the D3034, so the ClearVue 6" blast gates will work with either one. The new blast gate design ClearVue is currently selling run about $16 ea., which is a bargain in my book. They are injection molded clear plastic and have a self cleaning feature to keep dust from building up inside. They are sized to a snug fit to the OD of 6" PVC ducting. I have several of them in my shop ducting system, and I highly recommend them.

In the event you want to make your own, this design from Alan Schaffter has a lot of merit: http://www.sawmillcreek.org/showthread.php?132453-Blast-Gate-Plans


----------



## MJCD (Nov 28, 2011)

I'll pick-up the 3034 tomorrow, Thursday, and provide an update with pricing.


----------



## MJCD (Nov 28, 2011)

Material arrived today: the conduit is 2729 (a surprise from my plumber-friend), and it's a dream to work with… the fittings are SDR 35, and they fit to the conduit perfectly. In about two hours, I had several branches run, several diverters, Ys and elbows pressure-fit (I'm not going to cement them).

Pricing - all 6":
Conduit (2729) $1.98/Lft
Ys: $25.58 each (ouch!)
45 degree elbows: $15.17 each
straight couplings: $9.69

These are delivered prices, after-tax.

Assuming the 2729 withstands the Clearvue's 16" impeller draw, this has been an excellent choice.
MJCD


----------



## paulnwa (May 22, 2011)

Great news! Yeah, the prices kind of take your breath away, but I suspect if you want to make yourself feel better, check out the prices of the some of the metal ducting and fittings…............. I agree with you, it is great stuff to work with. Just finished helping a friend plumb his system with 6" D2729-he just made a simple box type miter box and cut it to length with a handsaw. The only problem he had was trying to accommodate the plethora of varieties of 6" flex ducting. I think he had about four different ones-all different weights, flexibility, and dimensions. But his system came out really nice. He especially liked the ClearVue 6" blast gates. You won't have any problem with the PVC withstanding the great airflow thru the ClearVue cyclone.

Please post some pics of your system when you get it up and running. Those of us with tiny shops like to see how the other half of the world lives…................


----------



## MJCD (Nov 28, 2011)

Paul:

My shop, my 1 & 1/2 car shop, is 17×23: so, it probably classifies as a small shop, as well. As a rule, I have more tools than talent.

The upgrade eliminates my 4" pvc into a Super Dusty Deputy into a 1.5hp Delta single-stage: all parts worked great, except for them being undersized to clear my TS & Router Table - end-of-run. The limiting factor was the 4" pipe, but then the SDD was limited by a 5" inlet, and then the Delta was only 1.5hp: the whole system constrained itself.

I chose the Wynn 6" flex hose; though, I have to admit I haven't opened the box yet - I'm still cutting & fitting the conduit. The conduit will run along the 23' wall, with a branch (mid-run) running behind the TS and RT, down the road, I'll branch the TS connection to include a draw from the TS blade guard.

I'm still waiting on the CV18.
MJCD


----------



## wapakfred (Jul 29, 2011)

The last thing you need worry about is the 2729 being sucked flat. If I recall it has a 3000# crush resistance (look on the side of the pipe)....remember this stuff is buried right beneath the soil and then driven over with tractors and implements. You will still have to seal the joints, and it's good to not glue them. Bit a thin bead of silicone around each joint with the DC running (that sucks it in a little) will give you a nice seal, a join that can still be easily separated and eliminates the really,really, annoying whistle that leaks in the joints sometimes have.


----------



## paulnwa (May 22, 2011)

With due respect to Fred's suggestion, I would encourage you to assemble your system without any sealant method and test for leaks. If any are found, the aluminum duct tape available at Lowe's or other places does a very good job of sealing the joints and may be easily removed if any future modifications are required.


----------



## MJCD (Nov 28, 2011)

The fit of the fittings to the conduit OD is excellent; though, my experience with 4" Sch40 is that the pressure fit wasn't air-tight - IMO the 2729 seems more precisely formed - I will check for leaks, then either duct-tape or apply the bead of caulk - Thanks, both excellent suggestions.

MJCD


----------



## mbs (May 8, 2010)

MJCD - not sure if you have the need but I made some very inexpensive 6" to two 4" Y's. You can see them in my workshop. It takes about 10 minutes to make them.


----------



## mprzybylski (Nov 21, 2011)

I apologize for reviving an old thread but I'm about to embark down this very same path and wanted to see how your success with this has been, MJCD? Did you end up sealing the joints any way?


----------



## jmos (Nov 30, 2011)

Matt,

I didn't re-read the whole old thread, but I'll risk commenting, hopefully I hit close to the point - I used 2729 for my system (I found it at an irrigation supply store.)

I didn't seal any joints, I just fully seated each joint and drove a couple self tapping screws to keep the pipes from pulling apart. It's been working great for years; I see no reason to seal, and a big reason not to (ease of disassembly.)


----------

