Plastic Vent Pipe for High Efficiency appliances

SpeyFitter

In the Viessmann Vitodens 100 Technical Manual online (Viessmann.ca) it says that their Coaxial Polypropolene Vent Pipe is rated to 248 F.

But, considering the Coaxial Pipe is technically "cooling" the exhaust pipe with the intake air on the outside, there may be no correlation perhaps? It also doesn't say in the manual that it is rated to S636 at the time, and even then the S636 temperature rating system may have different protocols.

As part of our local (Terasen Gas) rebate program for a few boilers I am installing (commercial in a golf & country club), they will only allow you to use stainless steel vent pipe for boilers to get the rebate, no plastic/CPVC 636, even if the manufacturer specifies the 636 is allowable as per their specs. Now stainless Z-vent (and others) is darn pricey. Makes 636 look attractive.

SpeyFitter

Plastic Vent Pipe

So the company I work for does a fair amount of installations, mainly hydronics, using Aquatherm Pipe (http://www.aquathermpipe.com).

If you don't already know, Aquatherm this is a German made Polypropolene Pipe that is fused together using Irons and will last longer than Copper in a lot of applications.

Well one curiousity of mine, and many others who use the product I'm told, is if we can use this stuff for the vents of high efficiency appliances. What peaked my interest first off was it's noted properties that they list as its benefits. And then learning that the Coaxial pipe offered by Viessmann for their boilers is Polypropolene.

Here in BC, all vent pipes used for the exhausts of high efficiency appliances must meet the S-636 standard. In a lot of peoples opinions, it's just another line of BS as we know PVC and CPVC pipe has worked fine for years, but I guess just more justification for someone or some company (Ipex for example) to gain a monopoly on the manufacturer of a pipe for a while where they can charge out the arse for it. For example, 4" CPVC pipe I was told recently was priced at $20 PER FOOT!!! But I guess when you factor in the $$$ it costs just to get the S-636 stamp theres probably some solid justification behind some of that pricing too.

So I recently contacted Viessmann and learned that their Coaxial Polypropolene pipe has just achieved/passed the S-636 standard.

So I have contacted Aquatherm about their climatherm and asked them about it (getting their pipe to meet S-636), I was told that the Germans (who make this stuff) like to offer their pipe with an insurance policy of at least 10 years (they actually don't offer it with a warranty, they offer it with an insurance policy instead at least for the hydronics/water end of it), of which in venting applications no Insurance company will touch any kind of insurance policy on it for obvious reasons.

So I responded to him that I didn't think anyone who sold S-636 pipe offered any kind of real warranty other then the conventional defects in workmanship or materials but the typical wear & tear/environmental factors aren't covered. And this kinda got me thinking.

So I ask, are there any manufacturers, 636 or otherwise, who offer a warranty or insurance policy on plastic vent pipe of high efficiency appliances???

Also, my question is how does this stuff react to situations where there might be an extreme issue with the boiler where it is firing with very rich or lean fuel mixtures and causing potentially dangerous combustion mixtures going up the flue?

My reasoning behind this is first this Polypropolene pipe is a way more environmentally friendly pipe,and in my opinion is probably better suited to exhaust venting than PVC or CPVC in the long run, plus there are no VOC's when installing that you have to inhale (the CPVC 636 glue will just about knock you off your ladder!!)

Unknown

Plastic Vent Pipe

I know what you mean Scott as I`m in Ontario.
As far as I know 636 is the only game in town for plastic vents, and as you know Ipex has a monopoly on that,, for now anyway,,, ;-)

Dave

The Boiler Dr.

S 636

What is the max temp range on Aquatherm? Basically anything other than furnaces are required to use CPVC on the exhaust because of the temperature. However, I have recently found a number of boilers where the exhaust temperature is right at the max rating for CPVC during "normal winter operation". It makes me wonder about the long term effects on the material.

Henry

ULC S636 is the only plastic vent pipe presently approoved for Canada. The platic pipe manufacturers use the sch 40 standards to manufacture PVC and CPVC vent piping. We install some Aquatherm piping also. When I was in Germany at their plant, we tested the heating pipe to the S636 standards. It passed. Their pipe is more costly to manufacture compared to pvc. The market is not very big in Canada, so the volume is not interesting. The US market where lawyers make a fortune, has no problem with abs, pvc or cpvc. The main reason the S636 standard is now required has to do with the poor installations and equipment failures that Ontario's TSSA had experienced. The provinces then forced it on us during our annuual gas code meeting. BTW, abs has a higher temperature rating than pvc!

SpeyFitter

ULC S636

Henry, I thought I heard somewhere that Solid Core ABS has a 170 F temp rating but could be wrong. That's what you mean, right? Not cell core, which most manufactueres specifically exclude in their I/O manuals.

Now when you say "poor installations," do you mean guys using different glue then that which is spec'd with the pipe? One of the things a fairly knowledgeable Emco rep has iterated to me is that what defines PVC and CPVC in North America, the standard or whatever, is fairly "vague" in grand terms, which is why most manufacturers of PVC And CPVC are fairly anal about requiring you to use their glue for their pipe, otherwise there could be problems, which seems to be something that does happen. Has something to do with the chemistries of the glue versus the pipe, etc, stuff that goes over my head for now.

I guess the one thing that is nice about the S636 system is guys are more likely now to use their glue since they offer seperate glues for it.

But the one thing I saw recently which pissed me off was an apparently old time gas fitter who did a high efficiency furnace and high efficiency gas hot water tank installation for a buddy for his big reno. He was recommended by his father in law who works for a gas company. Instead of the guy using the proper PVC 636 glue for the Ipex 636 PVC, he used the 636 Transition glue (which says it allows you to transition from ABS to PVC or CPVC, or vice versa or from PVC to CPVC) for everything. Yes, not technically wrong, but also not technically right in my opinion. Kind of a lazy way to do it.

Henry

ABS solid core starts to deform at 217F. Try using PVC DWV for a steam humidifier drain! You will get spaghetti soon, not so with ABS. We had only one bad installation with ABS. That wa because our team decided not to follow instructions and used an old can of ABS glue. The joints all fell apart within a season.

ALL sch 40 and 80 PVC and CPVC pipes follow an ASTME and plastic standard. Therefore, as long as you use a PVC or CPVC glue from any manufacturer, it will work. The ABS glues are adhesives while the PVC and CPVC are cement like and they actualy deform the surface of the the pieces for a more solid bonding. The glue used for S636 is not a proprietory product except for the pigments added. But now we have to follow the manufacturer's certified instructions which specify that there is no mix and match. We have had no problems previously so, it is a profit minded instruction sheet.

Transitional glue is not aprooved by any S636 plastic pipe manufacturer!

SpeyFitter

I know a guy who works for a wholesaler who attends all kinds of standards meetings. The information I shed for you concering the wide "berth" that defines CPVC and PVC and the subsequent various manufacturers being fairly adamant about you using their glues is something I learned from him (he is EXTREMELY knowledgeable about the industry and has all sorts of stories about how products evolved and why some fail, etc. - he is very interesting guy to talk to), as well as a job we did where IPEX supplied us directly with their products (A Leed Platinum project) where they specified to me to only use their glues on their products quite adamantly, and it wasn't a profit issue seeing as how I didn't need to buy the glues.

Ipex offers a CPVC/PVC/ABS glue for S636 applications! It's honey coloured and very similar to their normal CPVC/PVC/ABS transition glue, at least in looks.