Inspector comes to his senses

HDE

New York Town Rescinds Ban on PVC Vent Systems



The Chief Plumbing Inspector for the town of Huntington, on Long Island, N.Y., informed AHRI that the town has rescinded the ban on the use of PVC venting systems for gas appliances and equipment. Huntington follows the New York State Fuel Gas Code, which allows the use of plastic vents for Category IV appliances where such vents are specified by the appliance manufacturer and are installed in accordance with the appliance manufacturer’s installation instructions.



Thanks for following your own adopted codes and manufacturers requirements sir!

Zman

Interesting

Just as the rest of the US heating world is starting to question PVC venting, they finally excepted it. I see much more PP in the future.

Carl

HDE

Alot of reasons for PP in the boiler world

Boilers often times would benefit from PP, and with availabilty getting stonger and cost coming down thats great.

What I have a problem with is grouping other products into the fight such as tank heaters, condensing furnaces and residential condensing tankless units. The uninformed and people with finiancial gains to be had use scare tactics against products that rarely see over 125 degree flue temps, no need for PP.

Steamhead

Part of the issue

when discussing units "that rarely see over 125 degree flue temps" is that if something goes wrong, the flue temps can rise dramatically.



The typical galvanized chimney connector used on non-condensing equipment can probably withstand over 1000° F- not sure how much more, but I seem to remember some of the old stack relays having vent slots that were to be opened on jobs which ran that hot, to keep the helix from distorting. Nowadays, we don't like to see gross flue temps over about 500° F even on older equipment, and lower is better down to a point where flue gases start to condense. That would amount to a 100% safety factor.



So the question is, on units "that rarely see over 125 degree flue temps"- how hot would the vent pipe get under the worst possible fault conditions?

TonyS

Lets count the number

of dead people from properly installed PVC vent systems over the last ,say 30 years.

0+0x0=0000

It becomes quite obvious that there is a dire need to replace this death pipe.

For those concerned about temperature, obviously stainless is the only choice.

The entire argument is ridiculous based on the facts.

Steamhead

Tony, until we see all the investigative reports

from cases like Lofgren, you can't be sure of that.



And we may never see them, since AFAIK they are sealed by court order.



Again, how hot would the vent pipe get under the worst possible fault conditions?

HDE

It was released

Early findings were published.

Boiler, to be unnamed here due to all fairness had a PVC vent system not solvent welded or supported. All venting regardless of material could fail under those conditions.

TonyS

I would say

If everything failed we could exceed 1000 degrees. That would exceed the temperature rating of both plastics.Adiabatically gas burns at 3000, in an atmospheric burner about 1800 to 2000.

Steamhead

Is there

a link?

Steamhead

Exactly

venting systems have to handle the worst possible case and still remain safe. The money that one would save using plastic over stainless doesn't sound like much when compared to a CO event or building fire. 

ChrisJ

I don't know

I have to be honest,  the B-vent we installed with my boiler may take a lot of heat, but do you think it could handle 2000F?  I doubt it as it has an aluminum liner and is only 1 inch from flammables on the outside.

I mean sure, the draft hood mixes a lot of cool air with it but lets say (worst case) for some reason someone put something under it that blocked it?  Something that just happens to be able to withstand 2000F without catching on fire it self.  At the same time the boiler looses all of its water and the temperature switch on the draft hood also fails.  Under those conditions the B-vent would also fail in my opinion.



Does this mean we should insist on a class A vent for everything?  Should the boiler be surrounded by aspestos or equivlant tile as well?



As many know I'm a homeowner not a pro, but I think we need some amount of confidence in the control systems of these units as well.  If we don't, then the control systems need to be improved not necessarily the venting systems.

TonyS

We have to be reasonable

If we tried to cover every base we would be driving our cars wil helmets, we would eliminate electrical wiring from our homes(#1 cause of fires and deaths in a home).

I think if we compare devices we bet our lives on everyday, tires,street lights, ect. PVC venting would rate at the top of the chart. You cant argue with facts. Unless you sell AGA APPROVED corrugated ss gas piping, then you can flat out lie and pay consumers one by one out of court.

I would bet if one case came back against the PVC manufacturers, they would print on the side of the pipe...not to be used for gas venting.

Bob Harper

pvc venting

We have had discussions on this here so please check the archives.



PVC is not listed by UL but Inno Flue's polypropylene is for ex. The UL Stds Technical Panel cannot agree on a std. for glued polymeric venting. The PP has a slip joint so it can handle changes in dimension with temperature and has a max. temp rating of about 100F higher than PVC. B-vent is rated for 570F max. Appliance's have stated clearances to combustibles, which reflect 'worse case' scenarios so you should not require additional shielding to combustibles.



All the pvc mfrs. I'm aware of stat in their literature not to use their product for combustion venting. No, if mfrs. had to print warnings on the pipe for all the unapproved uses, you would only be able to buy 100 ft. diameter pipe to make room for all the warnings. They don't have to be idiot proof. Note that using pvc for combustion venting results in a transfer of liability or an assumption of risk by the appliance mfr. so the pvc mfr. actually has very little exposure.

TonyS

That was probably the same

panel that approved ultravent and plexvent and csst.

PVC has over 30 years behind it. Furnaces make up 92% of the heating systems in the USA and have alot of plastic on them including the draft inducers. The world has enough problems right now and PVC Venting isnt one of them.

Steamhead

Actually

I said we don't like to see stack temps higher than 500° F, and the typical non-condensing chimney connector might handle at least 1000° F, since the old stack relays had to have their vent slots open at that temperature.



At 2000° F, all bets are off.

HDE

This is pretty factual

http://www.scribd.com/doc/57752470/Estates-of-Parker-Lofgren-and-Family-Versus-Marlin-Brown-Et-Al



Around page 10 mentions fittings not primed, glued, supported

Steamhead

That was the original complaint

is there any record of the outcome? 

Jason_13

PCV to CPVC

The codes inspector around Richmond VA does not allow the connection of PVC to CPVC with glue. The guys are starting to run all CPVC which is about the same price as stainless steel vent.

HDE

Some

Criminal case dismissed against installer, inspector + town so far. Statue of limitations ran out.

I suppose prosecution didn't push and judge stalled.



Civil case not decided but lack of prosecuted crime doesn't help.



A lot of good is coming out of this which includes CO detectors required.

SWEI

CPVC to PVC

Unfortunate, because a few feet of CPVC on the hot side can really take the stress off.

Jean-David Beyer

The codes inspector around Richmond VA does not allow the connection of PVC to CPVC with glue.

Instructions for my W-M Ultra say I can use PVC Schedule 40, PVC-DWV, CPVC Schedule 40, or ABS-DWV schedule 40. I can also use AL29-4C. They specify a different cement and primer for each kind of plastic.



They also say



"WARNING Plastic piping -- Do not attempt to connect different types of plastic piping together.



"NOTICE: Do not use cellular core pipe.