# Science lab



## red_devil (Mar 23, 2011)

I recently started the (awesome) job of doing glass pipe( dwv) in 4 science labs in a high school. I got the hang of working with it and it does kick serious butt. 

My issue is, using ontario code, How can I possibly vent a fd and a lab sink? The lab sink is an island style so no continous waste and vent is allowed. rembering the job being all glass (including vents through roof) and the cost factor. Material must be kept to a minimum. And I don't think they make a glass cheater vent :laughing: and I don't know if island venting is still allowed in obc. 

Any advice at all would help as this is really puzzling me!?!


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## NYC Plumber (May 4, 2011)

If you dont want to do island sink venting cause of the amount of fittings, pick it up like a shower, ptrap and vent on floor below.
Ive seen it done like that and inspectors will let it go. If you think about it, its actually a better job also imo.


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## justin (May 14, 2010)

red_devil said:


> I recently started the (awesome) job of doing glass pipe( dwv) in 4 science labs in a high school. I got the hang of working with it and it does kick serious butt.
> 
> My issue is, using ontario code, How can I possibly vent a fd and a lab sink? The lab sink is an island style so no continous waste and vent is allowed. rembering the job being all glass (including vents through roof) and the cost factor. Material must be kept to a minimum. And I don't think they make a glass cheater vent :laughing: and I don't know if island venting is still allowed in obc.
> 
> Any advice at all would help as this is really puzzling me!?!


im from tx. can u loop ?


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## red_devil (Mar 23, 2011)

I forgot to mention the traps for these sinks are pencil traps and have to be under the sink, which now that I think of it, aren't really traps just collect debris, pencils etc. So I think I will have to find a way to gang trap this and I think I can fix my issue that way. 

I don't even know if we can island vent in ontario, never came by this. What do you mean by loop? Loop and circuit? 

BTW I'm gonna take pics and make a vid when I'm done because this is by far the coolest pipe I have ever worked with in my life. My fav. part is cutting it, its so easy.


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## justin (May 14, 2010)

red_devil said:


> I forgot to mention the traps for these sinks are pencil traps and have to be under the sink, which now that I think of it, aren't really traps just collect debris, pencils etc. So I think I will have to find a way to gang trap this and I think I can fix my issue that way.
> 
> I don't even know if we can island vent in ontario, never came by this. What do you mean by loop? Loop and circuit?
> 
> BTW I'm gonna take pics and make a vid when I'm done because this is by far the coolest pipe I have ever worked with in my life. My fav. part is cutting it, its so easy.


u dont know what a loop vent is. maybe someone with a pic csn show u one.









heres one


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## RW Plumbing (Aug 16, 2010)

red_devil said:


> I recently started the (awesome) job of doing glass pipe( dwv) in 4 science labs in a high school. I got the hang of working with it and it does kick serious butt.
> 
> My issue is, using ontario code, How can I possibly vent a fd and a lab sink? The lab sink is an island style so no continous waste and vent is allowed. rembering the job being all glass (including vents through roof) and the cost factor. Material must be kept to a minimum. And I don't think they make a glass cheater vent :laughing: and I don't know if island venting is still allowed in obc.
> 
> Any advice at all would help as this is really puzzling me!?!


No, they don't make a glass AAV. They do make an acid system AAV though, and they make adapters from glass to spears sch 80. The adapter has the ridge end on it and you put it on the glass with that rubber/stainless coupling. Works pretty slick, we had to do an old school chem lab a few years ago and used the adapters to adapt onto the main. We got them from a supplier called modular piping supply. They basically carry everything plastic.


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## RW Plumbing (Aug 16, 2010)

justin said:


> u dont know what a loop vent is. maybe someone with a pic csn show u one.
> 
> heres one


A loop vent is an island vent. I've heard it called loop island and return vent. Three names for the same thing.


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## NYC Plumber (May 4, 2011)

RW Plumbing said:


> A loop vent is an island vent. I've heard it called loop island and return vent. Three names for the same thing.


Ive heard all those terms also, the correct term is island vent though.
A loop vent technically is something else, and a return vent is a made up term.


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## justin (May 14, 2010)

NYC Plumber said:


> Ive heard all those terms also, the correct term is island vent though.
> A loop vent technically is something else, and a return vent is a made up term.


in texas that is a loop vent, or island vent


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## NYC Plumber (May 4, 2011)

This is the definition of a loop vent.

loop vent
1. A vent arrangement for a group of plumbing fixtures; consists of a vent pipe which is connected to the waste or soil branch immediately before the first fixture of the group and immediately before the last fixture of the group; the two connections are then “looped” together and connected to the vent stack.
2. The same as a circuit vent except that it loops back and connects with a stack vent extension of the soil stack instead of a separate vent stack.


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## NYC Plumber (May 4, 2011)

Really who cares im just being technical, i know what you mean and plenty of people call it a loop vent.


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## justin (May 14, 2010)

NYC Plumber said:


> This is the definition of a loop vent.
> 
> loop vent
> 1. A vent arrangement for a group of plumbing fixtures; consists of a vent pipe which is connected to the waste or soil branch immediately before the first fixture of the group and immediately before the last fixture of the group; the two connections are then “looped” together and connected to the vent stack.
> 2. The same as a circuit vent except that it loops back and connects with a stack vent extension of the soil stack instead of a separate vent stack.


awesome


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## TX MECH PLUMBER (May 27, 2011)

Here guys. I believe NYC is correct about the term but it has grown to be a well known slang for island vent These are both known as loop vents !!


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## Tim`s Plumbing (Jan 17, 2012)

justin said:


> in texas that is a loop vent, or island vent


In Mass it is called a Bow vent.


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## red_devil (Mar 23, 2011)

holy crap haha ya an island vent... 

Don't worry I got ya. I figured out with the obc and gang trapping is permitted so im all good. Thanks guys.


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## billy_awesome (Dec 19, 2011)

I'm from Ontario. I might be able to help you out on some code.

Island vents are not legal in Ontario code.

Your best bet IMO might be to circuit vent some fixtures, your going to have to be very creative how you do this. I've never seen that much glass work must be an impressive job, best of luck and let it know how it goes!


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## The real E.P. (Aug 9, 2011)

red_devil said:


> holy crap haha ya an island vent...
> 
> Don't worry I got ya. I figured out with the obc and gang trapping is permitted so im all good. Thanks guys.


Good call .. Off the top of my head washing machines, lab sinks, floor drains ( not where they can receive organic waste) and shower drains think that's all


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## red_devil (Mar 23, 2011)

Yup you nailed it on the code. I forgot the reference but thats what I am and will be doing. Glass is neat and really easy to work with but is extremely expensive. Knowing that your holding a piece of pipe 5 ft long worth over 300 bucks can be intimidating. And a ten footer, I don't even want to know the cost. 

I've had almost every trade/ person on the job site come in and make a bong reference lol


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## NYC Plumber (May 4, 2011)

billy_awesome said:


> I'm from Ontario. I might be able to help you out on some code.
> 
> Island vents are not legal in Ontario code.
> 
> Your best bet IMO might be to circuit vent some fixtures, your going to have to be very creative how you do this. I've never seen that much glass work must be an impressive job, best of luck and let it know how it goes!


How do you vent an island sink?


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## red_devil (Mar 23, 2011)

trap under floor using your max. trap arm length ( it think 1 m or 1.2 m) and back vent. Just be sure to install a co under sink.


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## billy_awesome (Dec 19, 2011)

NYC Plumber said:


> How do you vent an island sink?


 
back vent or a wet vent.

they changed our code in 2006 to allow a 4ft fixture outlet pipe. (to allow for ptraps under floor)

The American code makes sense for island vents, without getting off topic would you treat the waste pipe like a wet vent and oversize it?


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## billy_awesome (Dec 19, 2011)

red_devil said:


> Yup you nailed it on the code. I forgot the reference but thats what I am and will be doing. Glass is neat and really easy to work with but is extremely expensive. Knowing that your holding a piece of pipe 5 ft long worth over 300 bucks can be intimidating. And a ten footer, I don't even want to know the cost.
> 
> I've had almost every trade/ person on the job site come in and make a bong reference lol


Where are you working? I'm off this week and looking for something to do, I'll stop by your job, give you a hand, and maybe break a fitting or two!

You definitely don't want to know how much those fittings cost, I did a job in 4" and I almost cried when I broke a tee.


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## NYC Plumber (May 4, 2011)

billy_awesome said:


> back vent or a wet vent.
> 
> they changed our code in 2006 to allow a 4ft fixture outlet pipe. (to allow for ptraps under floor)
> 
> The American code makes sense for island vents, without getting off topic would you treat the waste pipe like a wet vent and oversize it?


Yeah thats what i said in a previous post, p-trap under the floor and pick up like a shower with a back vent. I really think that is a better job.
I dont see how you can wet vent an island sink though, maybe a pic would help?
As for oversizing i dont think its neccasary, the vent just gets tied back into the waste in case there is a stoppage. But everything else works normal.
Actually wet venting is very new in nyc, i know the basics but i am not really familiar, we just vent everyting so you cant be wrong lol.


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## billy_awesome (Dec 19, 2011)

NYC Plumber said:


> Yeah thats what i said in a previous post, p-trap under the floor and pick up like a shower with a back vent. I really think that is a better job.
> I dont see how you can wet vent an island sink though, maybe a pic would help?
> As for oversizing i dont think its neccasary, the vent just gets tied back into the waste in case there is a stoppage. But everything else works normal.
> Actually wet venting is very new in nyc, i know the basics but i am not really familiar, we just vent everyting so you cant be wrong lol.


Wet venting (modified stack venting) is crazy here in Ontario, basically everything we can possibly do is wet vented, its actually a superior way of venting besides individual venting, but saves so much time and labour.

I hope I don't upset anyone on this one, but back venting is actually the worst option in venting. Water always wants to find it's own level, and the hydraulic gradient will push water back up the back vent stopping air from entering the waste pipe.

But in my opinion, back venting works JUST FINE!!!!!!!!!!!!!!

NYC Plumber: I'll draw a pic later when im not buzzing!


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## NYC Plumber (May 4, 2011)

billy_awesome said:


> Wet venting (modified stack venting) is crazy here in Ontario, basically everything we can possibly do is wet vented, its actually a superior way of venting besides individual venting, but saves so much time and labour.
> 
> I hope I don't upset anyone on this one, but back venting is actually the worst option in venting. Water always wants to find it's own level, and the hydraulic gradient will push water back up the back vent stopping air from entering the waste pipe.
> 
> ...


I disagree that wet venting is better than a back vent, you would only have water in the vent if there is a stoppage.
The vent should come off the waste at an angle of 45 or greater, so under normal conditions you woldn't have that.
Wet venting your vent is being used as a waste line all of the time!
I think what your saying the island sink is what i would consider a combination waste and vent system. 
Where you oversize the waste line? Could be a difference of terms, but that is not a better method of venting either imo.


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## NYC Plumber (May 4, 2011)

Actually i was referring to a revent, a back vent is actually the best type of vent you can install.


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## billy_awesome (Dec 19, 2011)

NYC Plumber said:


> I disagree that wet venting is better than a back vent, you would only have water in the vent if there is a stoppage.
> The vent should come off the waste at an angle of 45 or greater, so under normal conditions you woldn't have that.
> Wet venting your vent is being used as a waste line all of the time!
> I think what your saying the island sink is what i would consider a combination waste and vent system.
> Where you oversize the waste line? Could be a difference of terms, but that is not a better method of venting either imo.


 
LOL we have so many different terms, we cant crack the usa vs canada language barrier 

We always learned in school the benefits of wet venting, not just labour and materials, but the waste of the wet vent clears out the fixture it serves.

Maybe another canuck can help me out on this one, I understand the code fully but I'm not the best at teaching, and still, I'm just an apprentice who talks a big game :thumbsup: LOL


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## NYC Plumber (May 4, 2011)

Terms are probably different lol, but i wont buy that wet venting is ever superior to any type of individual vent.
If you have waste passing through a vent you will have more pressure flucuations and a greater chamce lose trap seal.
Only place i agree with the washdown, is where you start your vent stack at the base of stack, you pick up the first fixture on the vent side and stack vent that fixture. That way your vent stack connection gets washdowned and wont clog up over the years.


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## billy_awesome (Dec 19, 2011)

getting too drunk for this thread......

WE NEED MIKE HOLMES!


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## NYC Plumber (May 4, 2011)

billy_awesome said:


> LOL we have so many different terms, we cant crack the usa vs canada language barrier
> 
> We always learned in school the benefits of wet venting, not just labour and materials, but the waste of the wet vent clears out the fixture it serves.
> 
> Maybe another canuck can help me out on this one, I understand the code fully but I'm not the best at teaching, and still, I'm just an apprentice who talks a big game :thumbsup: LOL


Obviously the benefits of wet venting is dollars...labor and material, but pumbing system wise individual venting is always better.


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## NYC Plumber (May 4, 2011)

billy_awesome said:


> getting too drunk for this thread......
> 
> WE NEED MIKE HOLMES!


Mike homes??? Lol we are looking to a GC for answers to deep plumbing theory lol!!


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## Airgap (Dec 18, 2008)

billy_awesome said:


> getting too drunk for this thread......
> 
> WE NEED MIKE HOLMES!


MAKE IT RIGHT!!!


:laughing:


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## plbgbiz (Aug 27, 2010)

red_devil said:


> ....rembering the job being all glass (including vents through roof) and the cost factor. Material must be kept to a minimum....


Maybe somebody should have given thorough consideration to the budget before deciding they wanted to build a laboratory. Why should the expensive desires/needs of the project be your burden?


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## The real E.P. (Aug 9, 2011)

NYC Plumber said:


> Obviously the benefits of wet venting is dollars...labor and material, but pumbing system wise individual venting is always better.


You are right if you have no budget or unlimited depth underground or floor joist space individual vents are best. With respect to vent stacks they are only required for larger building over 4 stories so for a school or residentially there is no need.... Although if there was one it would make life easier but would cost more money... As for back venting not superior in anyway because of hydraulic gradient


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## NYC Plumber (May 4, 2011)

Yeah why use glass? They make plenty of plastic pipes that can handle that type of waste nowadays....


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## The real E.P. (Aug 9, 2011)

NYC Plumber said:


> Yeah why use glass? They make plenty of plastic pipes that can handle that type of waste nowadays....


I think it's for acid waste or for sanitation reasons farms used to used glass for dairy but now use stainless steel


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## NYC Plumber (May 4, 2011)

The real E.P. said:


> You are right if you have no budget or unlimited depth underground or floor joist space individual vents are best. With respect to vent stacks they are only required for larger building over 4 stories so for a school or residentially there is no need.... Although if there was one it would make life easier but would cost more money... As for back venting not superior in anyway because of hydraulic gradient


Ok we have a bunch of differences in our codes here i think. I was referring to the vent stack only for the washdown.
What is a back vent to you? If you look at my pic in the previous post its the middle example.
i really dont see how that is not the best type of vent you can install??


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## NYC Plumber (May 4, 2011)

The real E.P. said:


> I think it's for acid waste or for sanitation reasons farms used to used glass for dairy but now use stainless steel


Yeah we install acid systems and use fuseal piping system. Its plastic designed for acid waste. Im just saying it would definitely help the tight budget andis an approved accepted material. Even for tough agencies like the sca.


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## The real E.P. (Aug 9, 2011)

NYC Plumber said:


> Ok we have a bunch of differences in our codes here i think. I was referring to the vent stack only for the washdown.
> What is a back vent to you? If you look at my pic in the previous post its the middle example.
> i really dont see how that is not the best type of vent you can install??


Back vent would be a t installed on its back on the trap arm


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## NYC Plumber (May 4, 2011)

The real E.P. said:


> Back vent would be a t installed on its back on the trap arm


Ok thats what i am calling a revent, i would agree that that is not the best. Still better than wet venting though.


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## MarkToo (Dec 17, 2011)

billy_awesome said:


> LOL we have so many different terms, we cant crack the usa vs canada language barrier
> 
> We always learned in school the benefits of wet venting, not just labour and materials, but the waste of the wet vent clears out the fixture it serves.
> 
> Maybe another canuck can help me out on this one, I understand the code fully but I'm not the best at teaching, and still, I'm just an apprentice who talks a big game :thumbsup: LOL



I'm guessing you're thinking of a "Continuous waste and vent" instead of a wet vent. Individually vented continuous waste and vent is the best.

A wet vented fixture would be next as by nature requires a continuous waste and vented fixture as the wet venting fixture.

Lastly a back vented (Canadian terminology and looking at the above drawing not the same as US terminology), fixture is last.

Drawing your hydraulic gradients shows the differences and why.

Wet venting, loop venting and stack venting while fully functional are essentially methods of saving labour and materials costs.


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## billy_awesome (Dec 19, 2011)

Thanks Marktoo, you cleared that up 

Just to be a prick....LOL, isnt a continuous vent different from a dual/individual vent???

As continuous vent is a vent that serves a typical wet vented group and its length and size is limited based on fixture units, and a dual/individual is NOT limited for length?

Hopefully this post gets 10 replies lol


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## MarkToo (Dec 17, 2011)

billy_awesome said:


> Thanks Marktoo, you cleared that up
> 
> Just to be a prick....LOL, isnt a continuous vent different from a dual/individual vent???
> 
> ...


LOL. I think you're making things too complicated.

Vents are going to be either wet or dry - that's it. The rest is terminology based on installation practices. Developed length and sizing of the dry portion is laid out in the code book for all venting regardless of name. Wet vents get sized according to the fixture/trap they serve and/or special considerations in the code. e.g. Same floor, order of fixtures (basin first, tub next, WC last), max and min distances, max fixtures, etc.


Regardless of the terminology we use to describe a particular install, the function of a fixture (good or bad), will have more to do with the workmanship of the install than the name of the venting used to serve that fixture.

Hope this makes sense...

Mark


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## AWWGH (May 2, 2011)

I recently did a science lab myself. Specifications required us to use a special neutralization tank at every since rather than the glass. Uses limestone chips, requires maint. once a year to add more chips.

Some of the other labs within the school had the glass piping and one neutralization tank.

Was a fun and different experience.


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## Keefer w (Jan 26, 2012)

Ehh, I miss plumbing like this. I need to get out of this service outfit


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## red_devil (Mar 23, 2011)

we tried the plastic but engineer wouldn't budge. Would be much cheaper and quicker. As for the cost its not about a budget I just want the best way with the least material thats all.


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## plumber666 (Sep 19, 2010)

Last time I did a big lab, the engineers drew it up as island loop vents which aren't allowed (or were'nt allowed, haven't even looked at the newest code). To make it code compliant, it took me some serious head scratching. There were several lab benches with a teacher's station in each class. I moved all the traps to below floor level and doubled back with the vented teachers sinks and used those as circuit and relief vents. Literally saved thousands of dollars on fittings, and that was the Blue-line plastic acid waste stuff, not the even pricier glass.

Only time I did a big glass job was a slab on grade school 19 years ago. Was all laid in accessable trenches and was one of the coolest jobs I ever did.

Did a reno a few years ago, existing glass pipe with new Blueline tied in all over the place. I found that if you're in a bind with no glass cutters, if you take it slow and roll the pipe as you cut, you can use an abrasive wheel chop saw. Just don't get the pipe red hot, and it won't crack, it is Pyrex after all.

Have fun!


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