# Stack Venting



## Plumber3653 (May 5, 2010)

Need some opinions regarding stack venting as IPC, UPC, local codes, what ya learnt all these years or what ever you feel, but relating to toilets specifically. I know that some prefer a vertical tee and some prefer a wye-combination vertically on a stack to branch off horizontally. Now if a toilet is only a few feet away from the stack, does anybody see the pros or cons of using the wye-combo as opposed to the tee to receive the drainage from the WC for stack venting? Any code violations? When testing for your license, do they look for one specifically on the drawings? Would like to hear what the rest of the world thinks.


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## Pipe Dreams (Feb 10, 2011)

Plumber3653 said:


> Need some opinions regarding stack venting as IPC, UPC, local codes, what ya learnt all these years or what ever you feel, but relating to toilets specifically. I know that some prefer a vertical tee and some prefer a wye-combination vertically on a stack to branch off horizontally. Now if a toilet is only a few feet away from the stack, does anybody see the pros or cons of using the wye-combo as opposed to the tee to receive the drainage from the WC for stack venting? Any code violations? When testing for your license, do they look for one specifically on the drawings? Would like to hear what the rest of the world thinks.


Wet vent everything :thumbup:


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## ogre plumber (Dec 30, 2010)

By code you should use the tee.


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## Plumber3653 (May 5, 2010)

Thanks ogre, that's what I was looking for. Depending on the location in the US. Some codes require tees and some allow both, but prefer wye combos (for cleaning and rodding, it directs cables and hoses in the direction of flow without risk of running up the stack.) But some codes state that the branch is not properly vented if a combo is used in place of a tee. Over the past few years there has been some debate in Pennsylvania between the state's implementing of the IPC and Philadelphia/Pittsburgh who already had more strict articles and codes for decades. By not allowing the wye-combo or a twin wye combo, for high rises and commercial buildings, there are more restrictions when it comes to freedom of design. I was curious as to how this has effected other plumbing communities. Other plumbers online, as well as myself, have found some unique requirements and don't agree with some of the IPC/UPC regs. Thanks for the response from K.C., ogre.


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## 422 plumber (Jul 31, 2008)

Always a tee. Ya know, I just had to do a little inspection on a house in my town that had a fire. A gal bought it and is gonna rebuild. So, me, the sparky, and the building inspector met the gc on site. There were two toilets, tub/shower, shower, k/s, one lav, and a w/m. Not. one. vent. So, I guess you don't even need vents. I dunno, it's puzzling.


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## Pipe Dreams (Feb 10, 2011)

jjbex said:


> Always a tee. Ya know, I just had to do a little inspection on a house in my town that had a fire. A gal bought it and is gonna rebuild. So, me, the sparky, and the building inspector met the gc on site. There were two toilets, tub/shower, shower, k/s, one lav, and a w/m. Not. one. vent. So, I guess you don't even need vents. I dunno, it's puzzling.


You don't need vents if you don't mind your house smelling like a sewer all the time.


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## PAplumberTyler (Feb 10, 2011)

Pipe Dreams said:


> You don't need vents if you don't mind your house smelling like a sewer all the time.


I rent a house near pittsburgh and there is all v200s not one vent even my bath tub has a v200


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## Pipe Dreams (Feb 10, 2011)

PAplumberTyler said:


> I rent a house near pittsburgh and there is all v200s not one vent even my bath tub has a v200


That's pretty crazy. Is that to code there? You're allowed to use them in certain applications here but I wouldn't. The only thing I would consider using one on is a laundry tray pump.


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## U666A (Dec 11, 2010)

By using a wye 45 you exceed the maximum slope on the trap arm and essentially starve the vent. San tee required here by code.


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## Plumber3653 (May 5, 2010)

BTW stack venting is allowed if the toilet is 6 feet or less from the stack allowing for hydraulic grade so that there is always air on the pipe. There is much more to the venting code than meets the eye around here. Yes, studor vents are allowed, but abused. No AAVs on commercial applications and residential buildings more than 2 stories or multi family dwellings. A single family rental actually counts as a commercial property. The handymen and quick service plumbers don't care to reconnect vents when drain work is done and certainly don't call for inspection.


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## nhmaster3015 (Aug 5, 2008)

U.A.til.I.die said:


> By using a wye 45 you exceed the maximum slope on the trap arm and essentially starve the vent. San tee required here by code.



Since the primary vent on a toilet is the open bowel and the s trap is always well above the inlet, it really should make no difference what fitting you use.


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## Plumber3653 (May 5, 2010)

Funny you should say that nhmaster. I recently debated the same principle with another plumber in regard to code differences. Part of my inspiration for the initial post, to find out what the plumbing community thinks and why. The sharing of information can make us all better at our trade.


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## U666A (Dec 11, 2010)

nhmaster3015 said:


> Since the primary vent on a toilet is the open bowel and the s trap is always well above the inlet, it really should make no difference what fitting you use.


Although I agree, the inspectors round here won't listen to reason. Not. One. Bit...


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## U666A (Dec 11, 2010)

Plumber3653 said:


> Funny you should say that nhmaster. I recently debated the same principle with another plumber in regard to code differences. Part of my inspiration for the initial post, to find out what the plumbing community thinks and why. The sharing of information can make us all better at our trade.


Funny YOU should mention that 3653,
Do you subscribe to Plumbing Engineer? In February's issue there is a lengthy article about the subtle differences between the IPC and UPC (did I get that right?). Any way, some of the mentioned differences aren't so subtle, and some are WAY off of what I've been taught. 

So is there an imaginary line down in the u.s. of a. Where one side uses one, and the other side uses the other? How does jurisdiction work with all of that?


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## Plumber3653 (May 5, 2010)

I could ask on another forum that I subscribe to as to what code is used and where. Seems that most plumbers I communicate with are upset with the UPC more than IPC. I agree with most of them. We have a blend of our local county plumbing code (enforced by the health department) and IPC. Many areas outside the two major cities (Pittsburgh and Philadelphia) have no plumbing code enforcement.


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## RealLivePlumber (Jun 22, 2008)

nhmaster3015 said:


> Since the primary vent on a toilet is the open bowel and the s trap is always well above the inlet, it really should make no difference what fitting you use.


 
Come again?


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## nhmaster3015 (Aug 5, 2008)

Toilets are self venting fixtures because they are self siphoning. they really don't need a vent to operate properly at all because atmospheric pressure on the water in the bowel provides all the vent necessary. the IPC now lists vent to closet distance as unlimited.


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## U666A (Dec 11, 2010)

nhmaster3015 said:


> Toilets are self venting fixtures because they are self siphoning. they really don't need a vent to operate properly at all because atmospheric pressure on the water in the bowel provides all the vent necessary. the IPC now lists vent to closet distance as unlimited.


Wow! Here it is 3m on the horiz, 1m on vert. That's just crazy!


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## Plumber3653 (May 5, 2010)

Maybe this will add some clarity to what is being said. Toilet traps need atmospheric balance to maintain trap seal after the flush. By design, if the trap here to be vented conventionally as a sink trap is, the siphon would not occur to flush in the first place. So...as soon as the water passes the flange the toilet is refilling and any air above the flow line of the pipe is balancing the pressure on the trap. Now if a volume of water upstream were to overwhelm the size of the pipe or a clog were to slow the draining, then you would have an additional siphoning of the trap in the toilet. That is why we have sizing, fixture units, etc. to prevent that and also relief, loop and circuit vents when floor mounted fixtures are upstream or downstream of the toilet. Toilets will require an additional relief vent at times, but if you were to put a series of 90 degree and 45 degree bends below the flange there will be no change in ow the toilet flushes or vents as long as balance occurs during the refill of the bowl.
That was a good diagnostics scenario for any new plumbers to the trade. A toilet that siphons itself down when not in use usually has a clog downstream and not a venting issue up through the roof as you may believe.:thumbsup:


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## beachplumber (Feb 7, 2010)

I have at least once. Come across 2 bathroom goups close together where the toilets would not flush. After augering and plunging the water would go down. If flushed it would not go down. Problem was solved after replacing AAV under lav.

Self venting?


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## Plumber3653 (May 5, 2010)

Curious one there, beachplumber. With two bathrooms and a bad aav venting the toilets it seems that there was more going on than meets the eye. Without a vent the toilets may double flush or siphon after flushing, but the whole bathroom group would suffer if the main drain was venting from a bad aav as well as the lav that the aav was on....it wouldn't hold a trap seal. For the toilets to not flush I would also think that there is already too much air and/or water compressing in the drainage system keeping the pressure on the other side of the trap too high to allow a flush. That situation would usually indicate a clog downstream and/or upstream. But, every new situation is an opportunity to learn.:thumbup:


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## nhmaster3015 (Aug 5, 2008)

beachplumber said:


> I have at least once. Come across 2 bathroom goups close together where the toilets would not flush. After augering and plunging the water would go down. If flushed it would not go down. Problem was solved after replacing AAV under lav.
> 
> Nope, can't be. something else going on there but it aint venting. Think about it for awhile. Think about a lav with an S trap. Why don't we like S traps? It's because S traps siphon. If you have ever filled a sink with an s trap and pulled the plug you have no doubt noticed how fast the vessel empties. That's because atmospheric pressure is pushing down on the body of water. It's amazing how many plumbers still think that venting effects draining.


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## beachplumber (Feb 7, 2010)

The aav wasn't my first thought
I do not believe there was any atmosperic vent.
It was a septic system on the ocean front.
Tides and storms can do strange things to the septic systems.
Sometimes afte a storm all that is left is a concrete tank.


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## Plumber3653 (May 5, 2010)

I am a huge advocate of proper venting and I will reply with this. Without a vent after the trap, water does not continue to flow as efficiently. Same concept as putting a drinking straw in a glass of water, put your finger on the top end and lift the straw from the glass. Water stays in the straw from atmospheric pressure pushing up. Remove finger and voila!, straw is vented and water flows from the straw. We just need to use the right info for the right job.
Nice to see that this thread has stimulated some thinking and communication.


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## Redwood (Sep 8, 2008)

beachplumber said:


> I have at least once. Come across 2 bathroom goups close together where the toilets would not flush. After augering and plunging the water would go down. If flushed it would not go down. Problem was solved after replacing AAV under lav.





nhmaster3015 said:


> Nope, can't be. something else going on there but it aint venting. Think about it for awhile. Think about a lav with an S trap. Why don't we like S traps? It's because S traps siphon. If you have ever filled a sink with an s trap and pulled the plug you have no doubt noticed how fast the vessel empties. That's because atmospheric pressure is pushing down on the body of water. It's amazing how many plumbers still think that venting effects draining.


Here we go again.... :laughing:
NH Master venting school is in session...:laughing:
Maybe we should kick back and let the students from the last class teach this one.... 

http://www.plumbingzone.com/f2/drain-cleaners-chemical-vents-9307/index3/#post123501

Venting by far is the most misunderstood topic in plumbing.... :laughing:


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## Redwood (Sep 8, 2008)

Plumber3653 said:


> I am a huge advocate of proper venting and I will reply with this. Without a vent after the trap, water does not continue to flow as efficiently. Same concept as putting a drinking straw in a glass of water, put your finger on the top end and lift the straw from the glass. Water stays in the straw from atmospheric pressure pushing up. Remove finger and voila!, straw is vented and water flows from the straw. We just need to use the right info for the right job.
> Nice to see that this thread has stimulated some thinking and communication.


Your straw analogy is 100% off base...

To do that your would need an airtight cover over the top of the toilet bowl or, sink...:whistling2:

Read through the thread I linked in the post above see if it makes sense to you.


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## Tommy plumber (Feb 19, 2010)

Gentlemen start your engines. The venting debate is about to begin anew.


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## lma1 (Feb 14, 2011)

The BCPC allows a vertical san tee, or a horizontal combination wye and 1/8 bend for a WC or a double tee or double combination for 2 WC’s, except when you have 2 back-outlet WC’s installed back-to-back, a double san tee is not allowed to use to connect the 2 trap arms. 

According to our Code, as long as you stick to (i): tram arm ≤ 9.84’, (ii) fixture outlet pipe ≤3.28’, and (iii) total change of direction of drain pipe ≤ 225° using a combination of 45° and 90° elbows where appropriate for a WC that discharges vertically and depends on siphonic action for its proper operation, you do not violate the venting rule.

The requirement that the total fall of the trap arm must be ≤ its inside diameter is excluded from the consideration when you satisfy the 
onditions above.

We have very strict rule on when an AAV (Studor vent) is permitted. We try to avoid using it.


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## Plumber3653 (May 5, 2010)

Redwood, the straw analogy is a simple example of physics and how having air in the pipe allows good flow. That is all it is. There is nothing off base at all. Fill a pipe with water and vent it, water flows. I can't see how something so simple can be off base. Please don't ruin a thread by creating controversy where there is none.


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## Plumber3653 (May 5, 2010)

Worse yet, Redwood, I never implied there was a real life giant finger over a giant straw as you described with the toilet scenario. Read all of the threads before posting, please.


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## RealLivePlumber (Jun 22, 2008)

The main purpose of a vent is to protect the trap seal of a fixture. A water closet that is not properly vented could have the water seal compromised by a slug of water passing that fixture.


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## RealLivePlumber (Jun 22, 2008)

nhmaster3015 said:


> Toilets are self venting fixtures because they are self siphoning. they really don't need a vent to operate properly at all because atmospheric pressure on the water in the bowel provides all the vent necessary. the IPC now lists vent to closet distance as unlimited.


You need the vent to protect the trap seal, . I.E. the water in the bowl. 

NSPC has limits on trap arm length and height.


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## easttexasplumb (Oct 13, 2010)

Since commodes have an S trap, proper venting is even more important for them.


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## jeffreyplumber (Dec 7, 2009)

In So cal UPC code we are all taught to use a san tee and not slope trap arm too much. however a toilet has a built in trap that puts the weir of the trap way above the inlet of the vent. for instance you could not run a trap arm horisontal below the floor to a lav and then come thru floor and put a trap on it. their is a special exception for a fixture as a toilet. Yes you could use a combi, it would be a obvious code violation but it would work just the same. To me being from new construction where everything is inspected it seems wierd but I dont think theres a thing wrong at all about it. When I see all this horizontal wet venting , studor vents, and a lot of other stuff looks funny. But theres more than one way to plumb you cross into another city or state and all the sudden everythings done a differant way


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## Redwood (Sep 8, 2008)

Relax boys...
Nobody is insulting your intelligence by saying vents are not needed in a plumbing system.... :no:

Everyone knows that they protect the trap seal....
Nobody here Myself and NH Master included want a poo smelling DWV System....
We are not saying not to install anything against any code...
This is Theory not what we do...

In fact I'd probably go so far to say as we both believe that AAV's are a product invented by Lucifer himself....:devil2:

The straw analogy doesn't fit when you look at the as built. The as built in addition to the hole at each end of the straw has a hole in the center where a toilet is installed, and that toilet has atmospheric pressure over the bowl. So rather than a finger on the top of the straw you will need a big thumb that you can cover the bowl of the toilet with as well. 

Unless the waste from the toilet is discharging into a well sealed unvented container such as an ejector pit without a vent or a septic tank a toilet without a vent will flush quite nicely. If it doesn't, look most likely for a clogged line or some other problem.

Seriously, Read that other thread I linked thoroughly, and if you have some new revelation bring it to the table...

I don't believe you will find any credible evidence to contradict what we have stated...:no:


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## Plumber3653 (May 5, 2010)

Okay, Redwood I see where the misunderstanding here is. I'll explain the straw analogy then it will be dropped.
In no way was the straw analogy intended to have any relevancy or attachment to how a water closet operates or is vented. It was simply to show those who may not understand the importance of venting other than the trap seal protection and how venting is useful throughout the drainage system. Any relationship that you think may have existed between the description and toilets never existed. If no vent existed on a toilet or other fixture, efficient water flow (nothing related to trap seals on toilets...water flow ONLY) would suffer.
Yes, I agreed and made clear as to how air on both sides of the trap on both fixtures and toilets are extremely important and that AAV are overused and abused. Large volumes of water would change pressure balance on a toilet trap seal and force a loss of the seal. 
I also referenced relief, loop and circuit vents and pipe sizing as tools that we use to reduce the risk of losing trap seals.
This thread was started only to see how changes to the codes have effected the ways we install piping (stack vented toilets) using traditional methods and how the plumbing community feels about these changes.
Years ago when high rise buildings were designed, many of the plumbing stacks were offset throughout the buildings. The engineers feared that long drops of vertical pipes with soil water could reach such speeds as to break the pipes at the bottom of the stacks. Codes and design required frequent offsets in the stacks to prevent this damage. Later they came to realize that water reaches it's terminal velocity at around 10 feet and the need for so many offsets was needless. To this day some plumbers still believe that so many offsets are needed in vertical stacks to avoid blowing apart fittings.
Sometimes things are not what they may seem and we can learn to dispel some of the myths that are so popular with our trade by sharing information. Who knows, maybe the story I just told was nothing but another one of those myths.


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## gitnerdun (Nov 5, 2008)

I know that about 15 yrs ago I did a bathroom over a garage. Came time to water test. Put a cap on the bottom of the 3", and filled tub to top. After inspection pulled cap and just a couple gallons came out. Tub still full. No other fixtures installed yet. We decide that something had to be wrong with the tub and passed a cable thru and down to the end of the 3". Then a light bulb came on, we cut the stub for the aav and all the water drained out. It was a good learning experience. I know this doesn't settle any toilet flushing or not, but it's all I got.

Aside from that I was always taught that the vent should be a close as possible to the toilet so that air could escape the path of the big rush of water coming. Also to stub up in 4" as to have more room for the goods coming fast.
Bob


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## jeffreyplumber (Dec 7, 2009)

3653, 
I think I may have mis stated about having to use a santee for a W/C I think a combi may be legal. I never seen it done that way and I am sure nearly all plumbers in UPC country have been tought not to use a combi in this fasion, but for a W/c I think it would be legal. However for a shower or tub or most any other fixture.
As for aav those are limited to rv or trailer. I seen them installed in a pinch where someone doesent want to go thru work to complete a sink add on. or outside bbq island. Can you put those aav in instead of a basic vent system or do you still needa vent going thru the roof in places that allow them? Kind of a cheap way to save labor and pipe on a job done right.


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## RealLivePlumber (Jun 22, 2008)

Signature line alert!!!!!! ^^^^^:whistling2:


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## Redwood (Sep 8, 2008)

Unless you are draining to a closed container that is not vented and pressurizes as the waste flows into it there is no reason why a lack of vents on the branches would cause the waste not to drain.

In addition in many cases the fall of the line will add a syphon effect causing the waste to drain faster. This ia a lot like when you are using a hose to drain an above ground pool and you move the hose further downhill to get higher flow.


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## PlumberPete (Nov 14, 2009)

Pipe Dreams said:


> You don't need vents if you don't mind your house smelling like a sewer all the time.


If you didn't have a any vents your home wouldn't smell. Your fixtures wouldn't drain properly. But, if there weren't any traps then the house would smell.


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## Redwood (Sep 8, 2008)

CardinalPumbing said:


> If you didn't have a any vents your home wouldn't smell. *Your fixtures wouldn't drain properly.* But, if there weren't any traps then the house would smell.


Nah...

They would drain just fine in most cases... :yes:

You'd just have sinks that sound like toilets....


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## beachplumber (Feb 7, 2010)

Around here as long as u have a main vent u can aav all the other fixtures ( not commonly done)

In my post above there very well could have been a belly in the line or some other issue. Many of our codes are based on a what if


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## Redwood (Sep 8, 2008)

beachplumber said:


> Around here as long as u have a main vent u can aav all the other fixtures ( not commonly done)
> 
> In my post above there very well could have been a belly in the line or some other issue. Many of our codes are based on a what if


That could do it...


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## Plumber3653 (May 5, 2010)

Redwood, I really hope you're not serious with some of the comparisons that you have made since my straw analogy. If so, you are taking similarities and ignoring the differences between the actions to have some point that escapes me. I'll assume you are just being sarcastic, especially with the post that a house without vents would drain just fine, but I guess that would be because of the siphoning effect, huh.
Sometimes people have just enough information in their head to give advice, but not enough to know if it is good or bad.
Well, I'll try to find a giant vacuum test lid for my toilet and put a hose in my pool outside and see which one drains faster than the straw in my kitchen that's full of water. Afterwards, I'll plug up all of my vents, since they do no good anyways and siphoning will let my sinks drain faster and test everything all over again. Results will be posted once I regain consciousness from the trauma my head will receive from banging it off a wall because SOME PEOPLE JUST DON'T EFFIN' GET IT!


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## easttexasplumb (Oct 13, 2010)

Venting scandal uncovered, turns out we don't need them it's just a "cash grab".


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## U666A (Dec 11, 2010)

easttexasplumb said:


> Venting scandal uncovered, turns out we don't need them it's just a "cash grab".


As soon as I get home I'm getting out the sawzall... Those pesky unneeded vent pipes have been pissing me off for years...


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## Tommy plumber (Feb 19, 2010)

U.A.til.I.die said:


> As soon as I get home I'm getting out the sawzall... Those pesky unneeded vent pipes have been pissing me off for years...


 



So you're gonna cut 'em? Just cap 'em off, that'll be easier...:laughing:


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## U666A (Dec 11, 2010)

Tommy plumber said:


> So you're gonna cut 'em? Just cap 'em off, that'll be easier...:laughing:


Old house, all in copper... I'm going to turn a profit of of this operation!


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## Airgap (Dec 18, 2008)

I'm going to keep this thread bumped to make sure Red sees it.....


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## Hillside (Jan 22, 2010)

Plumber3653 said:


> Redwood, I really hope you're not serious with some of the comparisons that you have made since my straw analogy. If so, you are taking similarities and ignoring the differences between the actions to have some point that escapes me. I'll assume you are just being sarcastic, especially with the post that a house without vents would drain just fine, but I guess that would be because of the siphoning effect, huh.
> Sometimes people have just enough information in their head to give advice, but not enough to know if it is good or bad.
> Well, I'll try to find a giant vacuum test lid for my toilet and put a hose in my pool outside and see which one drains faster than the straw in my kitchen that's full of water. Afterwards, I'll plug up all of my vents, since they do no good anyways and siphoning will let my sinks drain faster and test everything all over again. Results will be posted once I regain consciousness from the trauma my head will receive from banging it off a wall because SOME PEOPLE JUST DON'T EFFIN' GET IT!


Keep us posted!!


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## Plumber3653 (May 5, 2010)

Yes, we must keep all those involved posted. There is a veritable fountain (fed with a 2" HDPE plastic water service over 800 feet long at 100+ psi with very little friction and elevation loss at .43 pounds per foot rise) of information that would be lost. Correction, these threads are now useless and the water has been tainted so terribly that a debate about the corrosive properties of chloromine on a copper water distribution system couldn't make them clean again. I regret asking the initial question, now. I guess it could still continue to provide some visual entertainment similar to watching an orangutan urinating in it's own mouth at the zoo. 
Have a great day, ya'll.


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## nhmaster3015 (Aug 5, 2008)

Well this one is actuall pretty easy to test and since I have an entire classroom full of stuff to do it, we have. Set up is simple. An ordinary lav, piped properly with P trap to an 1 1/2 san tee with vent up and vertical drain down. Cap the vent and guess what happens? The lav drains just fine. In fact, in time tests between capped and vented, there is absolutely zero difference in the amount of time it takes to drain. That would be because the vent has no effect on the drain. All it does is break the vacuum when the fixture does drain. I know this concept is hard or some guys to wrap their heads around but it is simple fluid hydraulics in action.


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## Plumber3653 (May 5, 2010)

Try this one out nhmaster. Without having any vents, simulate a bathroom group. Tub, toilet and lav. Don't even have a vertical stub coming up for any stacks or vents. Y'know, MythBusters-type-real-life simulation. No need to cap if no vent was ever put in. All s-traps and toilet filled with water. Just a horizontal 3" main run from the toilet, continue upstream to the tub and then the lav with an s-trap (no tee vertcal with a cap, an s-trap.) Fill the tub with water and open drain, while it's draining flush toilet and/or let sink drain too. Check effect(s) on fixtures and drainage time. Now install true vents and test simulation again. This was a lab simulation that I witnessed. You will see a difference in the performance of the plumbing system with vents installed. Or....maybe that slow draining sink that I added a vent to down the street from my house was just my imagination. The water drained sooooooo slowly. Handy man remodel job on lav drain running approx. 10 feet horizontally to stack without a vent. I added AAV...voila...sink drains fast, smooth and doesn't have that stinky after odor. Next time I'll just let it be and print a copy of your post and tell the customer "sorry, nothing we can do for ya, basic hydraulic stuff goin' on here that's out of my control." 
Vents..they're not JUST for trap seals.


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## PrecisionPlumb (Feb 17, 2011)

Im not going to read all these posts but if you use a wye as apposed to a tee you are removing the airflow allowing it to vent


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## Plumber3653 (May 5, 2010)

Sometimes "Real Life" is the best teacher. Learned a lot in that classroom.


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## Plumber3653 (May 5, 2010)

:bangin::wallbash: Finally found a use for these things.


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## Airgap (Dec 18, 2008)

Plumber3653 said:


> Yes, we must keep all those involved posted. There is a veritable fountain (fed with a 2" HDPE plastic water service over 800 feet long at 100+ psi with very little friction and elevation loss at .43 pounds per foot rise) of information that would be lost. Correction, these threads are now useless and the water has been tainted so terribly that a debate about the corrosive properties of chloromine on a copper water distribution system couldn't make them clean again. I regret asking the initial question, now. I guess it could still continue to provide some visual entertainment similar to watching an orangutan urinating in it's own mouth at the zoo.
> Have a great day, ya'll.[/QUOTE]
> 
> The "ya'll" gave you away....


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## Plumber3653 (May 5, 2010)

What did it give away? I'm not from the south. Maybe it has been my travels around the country and the world that I picked up the "ya'll" or maybe I just randomly typed out a word and it's origin and use are meaningless.
Thanks for noticing, Airgap. It did make me feel special...even for a moment. It was nice.


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## Airgap (Dec 18, 2008)

yer welcome....


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## Redwood (Sep 8, 2008)

*Gentlemen... Gentlemen... Relax... Take a Breath and Read....

In No Way Am I Suggesting That Vents Be Eliminated!
Keep On Installing Them In Accordance With Your Locally Used Plumbing Code....
They are necessary to equalize the pressures within the DWV system and protect the trap seal!*

Now with that hopefully established to avoid another 3 pages of posts by those that couldn't understand what was stated, I will again state....

*Vents in no way enhance the draining of any line unless the line is draining to a sealed unvented container such as an improperly installed ejector pit without a vent or, a septic tank or, a clogged line. Additional factors may come into play such as House Traps or Bellied lines which may create a double trap effect.*



Plumber3653 said:


> Vents..they're not JUST for trap seals.


*That answer could very well get you an incorrect answer marked on many license tests....* :laughing:


*With that said I Repost this from the other thread on this subject...*

I just find it funny that some of these guys have failed to learn from the Dead Men...

Consider these excerpts...







































This isn't anything new I'm telling you....

This has been known for many years and this knowledge was passed down to us by those long gone...

Somewhere your education in the field of plumbing has failed to teach you the basic principles of plumbing....

I'd suggest to some of you rather than sit there looking at the same old ads and the same old rehashed be a franchise articles in todays trade magazines go way back and learn the basics from the Dead Men...

We may not use crown vents, drum traps, and wipe lead anymore...
But the principles remain constant....

It's been going downhill since the Romans built the Aqueduct and some things never will change...:whistling2:

Excerpts taken from:










*In addition Protech went out in the middle of the night to conduct an experiment in the last thread to prove that drains do indeed work without a vent...

Protech's Video links:*





 




 




 
:whistling2:

Seriously Keep on installing vents!
I'm not telling you to stop!
But unless those conditions exist which I have stated repeatedly throughout this thread and the other one...

The water will drain fine without a vent!
Your traps however will make a noise like a flushing toilet... :yes:


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## nhmaster3015 (Aug 5, 2008)

dunno what you witnessed and know even less of the circumstances involved I'm just telling you that vents to not make water flow any faster. Ask youself what you think the vent is really doing? The purpose of a vent is to equalize pressures within the plumbing system in order to protect trap seals. Properly installed vents and properly installed plumbing systems do not rely on the vent to insure draining of the fixture. If the system will not drain without a vent it is because there is a restriction in the line, downstream of the drain that is not allowing the air in the pipes to move with the drainage. Usually this is caused by a hump in the pipe that traps water. In that case the vent near the fixture expells the air and allows the fluids to fill the pipe to the point that gravity drains the fluid past the hump in the pipe. I don't know how to make that any more clear but if you take some time to wrap your head around the situation you will come to the same conclusion. No doubt the underslab piping in your case was installed improperly and improperly pitched.


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## Plumber3653 (May 5, 2010)

No, the piping was exposed and hung horizontally on the other side of the wall. 1 1/2" pvc for the lav. Everything easily visible and there is no mystery about what happened. I think that the difficulty in wrapping one's head around something is this. Text and history teach us a lot, but by using the words of a book to be the end all-be-all of information is limiting our ability to learn.
To say that vents are ONLY for trap seals is inaccurate. Read between the lines of the information. We're not taking a plumber's exam here,either. Yes, primary purpose is for trap seals. Is there no secondary purpose as you propose? 
It seems that this is a discussion between which is more important for a car to run...the engine or the tires; you are arguing "the engine" and my argument is that "the whole car has to run properly..tires and all" but your focus is on the engine. 
I give up with this. I was trying to share some valuable, practical information from my experiences and narrow-minded stubbornness is just tearing it apart.
Don't just interpret the information from my posts to meet your desired ends.
You will just keep making the same statements over and over and over again because you are right and I am wrong. 
Guess life will go on for some of us.


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## nhmaster3015 (Aug 5, 2008)

Plumber3653 said:


> No, the piping was exposed and hung horizontally on the other side of the wall. 1 1/2" pvc for the lav. Everything easily visible and there is no mystery about what happened. I think that the difficulty in wrapping one's head around something is this. Text and history teach us a lot, but by using the words of a book to be the end all-be-all of information is limiting our ability to learn.
> To say that vents are ONLY for trap seals is inaccurate. Read between the lines of the information. We're not taking a plumber's exam here,either. Yes, primary purpose is for trap seals. Is there no secondary purpose as you propose?
> It seems that this is a discussion between which is more important for a car to run...the engine or the tires; you are arguing "the engine" and my argument is that "the whole car has to run properly..tires and all" but your focus is on the engine.
> I give up with this. I was trying to share some valuable, practical information from my experiences and narrow-minded stubbornness is just tearing it apart.
> ...


I don't believe that either I or Red have any desired ends, just knowldege of basic plumbing theory. No narrow minded stubbornness either. Facts are facts. The only purpose of vents is and always has been to protect the trap seal. Every single modern plumbing text says the same thing.


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## klempner (Mar 4, 2011)

I'm no know it all in this or any other matter, but decided to look at the IPC commentary after reading the discussion here.

Intro to chapter 9: "The purpose of venting is to protect the trap seal of each trap." "If there were no traps in a drainage system venting would not be required." "Some have related a vent system to the open/closed straw phenomenon. . . . The claim is made that without a vent, the drainage system would not properly operate. . . . This analogy is not completely accurate because a drainage system is not flowing completely full. . . . Drainage systems are designed to flow partially filled." "Pressure fluctuations are created by waste flow in the drainage system. Venting is not intended to provide the circulation of air within the drainage system."

Not what I was expecting. May not be right, but I've been very impressed with the IPC commentary.

As to AAV, the IPC says (917.3) that they must only be used on fixtures that connect into a horizontal drain branch on the same floor. Perhaps that was the problem with the tub example earlier.


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## U666A (Dec 11, 2010)

All I can add to this is what I have seen in a classroom setting. Anyone that attended tradeschool at Mohawk in Stoney Creek will remember the glass piping arrangement in the shop. The have a stack set up with a basin tied it very close to a horizontal offset and two toilets tied in above. It is adequately vented, c/w mechanical isolation valves on the vents. If you close the valves on all of the vents and flush both of the toilets, when the slug of waste reaches the 90 below the basin, the pipe is full. And as it rushes by, it siphons the trap on the basin. Other than that, the timing of the drainage, and all other factors remain unchanged.

Therefore, sole purpose of vent is to protect trap. This is also an extreme case how itis tied in low with a very short trap arm. Seldom would this be practical in real life and if the circumstances were slightly different, I'm not sure this would happen.

$.02


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## BROOKLYN\PLUMB (May 21, 2010)

What about the effects that the fresh air inlet has on venting?

I learned that a secondary effect of vent was the drying of waste lines keeping them from rotting out (cast iron/galvanized) not that this is why we vent just a good consequence of it 

Also side note before they put the holes on top of the sewer manhole covers even with vents, gas entered in the house thru the traps and into homes (this occurred after heavy rain)

Sent from my EVO 4G using Plumbing Zone


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## jeffreyplumber (Dec 7, 2009)

They are necessary to equalize the pressures within the DWV system and protect the trap seal!

Yall got me scratchin my head . I thought the vent did both protect the trap seal and help drain. perhaps not allways needed to help drain but depending on factors could assist. 
Now Im not so sure. Above is a quote from redwoods post that 2 purposes of a vent to protect trap seal and equalize presure in dwv system. Im not going to change how I plumb, but good to know when diagnosing a problem. It sound like most of you aggree though that if there is a slow drain the problem cannot have anything at all to do with the vent system. Is that the general consensus? I really didnt think so befor but now I think the vent is not involved in poor drainage


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## suzie (Sep 1, 2010)

U.A.til.I.die said:


> By using a wye 45 you exceed the maximum slope on the trap arm and essentially starve the vent. San tee required here by code.


 exactly thanks


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## Plumber3653 (May 5, 2010)

OH NO!!! A few plumbers may actually agree that there is more of a purpose to the design of vents!! Let's see how many actually have the stones to stand by me on this one. 
The scenario with the toilet tub and sink was constructed above ground in a plumbing lab to show how plumbing systems work, nhmaster. It was also set up for the "Venting Effects on a Drainage System" lab. You may be able to find these labs at independent schools and VOTech schools. Things happened as I have stated. The lav sink at a customers house was as I stated. Just because it isn't in your book, doesn't mean that it can't be real.
Also note...some of the stuff you may find in the IPC code is wrong. Some is correct...some is not. Many other plumbers will agree with me on that one too.


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## Plumber3653 (May 5, 2010)

Jeffreyplumber, you are correct that most slow drains are NOT a venting issue. Most are drainage and RARELY a vent. I have stated that many times over the years to plumbers who want to snake vents when a toilet bubbles as a tub drains. That doesn't change the fact that venting issues can effect drainage.
If you had been taught that drainage after the trap is also effected by venting, then you are on the right track and don't let inaccuracies in a book written by inexperienced engineers or plumbers tell you differently.


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## Plumber3653 (May 5, 2010)

The plumbers and sanitary engineers from Pittsburgh and Philadelphia have already stifled the IPC reps for the state on those points. We have added some of the IPC codes to our own, but most are still under review and logic, common sense and experience are showing that there are still many faults with several codes in the IPC. If any plumbers from Phili have been following this over the past 6 years, they may agree. Improving on what we know is a good thing, but change just to have change without reason is a bad thing.


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## Plumber3653 (May 5, 2010)

I guess if the IPC allowed house traps and using the venting logic in these threads, we could all make plumbing smarter and easier by doing this:
1. No p-traps on any fixtures and toilets will have no trap, just drop straight into the flange and flush into it.
2. No vents anywhere inside the house.
3. Only one trap, the house trap. Fresh air inlet on one side and venting provided through the main sewer.
4. Without vents, no air will be circulated to get the house stinky. Drainage is not effected by the lack of vents either.
5. Casting of toilets will be cheaper without a p-trap, fewer materials needed for construction or service work and less labor involved. Everybody saves money on costs. Both plumber and consumer.
6. With just one p-trap on every house, no need for longer education or interpretation of code. Venting chapters can be removed from books and save students on tuition costs. Everybody wins.


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## Plumber3653 (May 5, 2010)

By the way. Can any IPC or UPC specialists explain how having a house trap on a building and fixture traps is considered "double-trapping"?
All of these years I thought that I knew what it was, then the IPC came along and redefined it. 
All these poor people with fixture traps and house traps living peacefully without knowing the imminent danger that could be lurking on their double-trapped household.
This should be interesting.
" A little rebellion now and then is a good thing." -Thomas Jefferson (1743-1826)

" One of the great pains to human nature is the pain of a new idea." - Walter Bagehot (1826-1877)

" Opinion has caused more trouble in this little Earth than plagues or earthquakes." - Voltaire (1694-1778)


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## Redwood (Sep 8, 2008)

Plumber3653 said:


> OH NO!!! A few plumbers may actually agree that there is more of a purpose to the design of vents!! Let's see how many actually have the stones to stand by me on this one.
> The scenario with the toilet tub and sink was constructed above ground in a plumbing lab to show how plumbing systems work, nhmaster. It was also set up for the "Venting Effects on a Drainage System" lab. You may be able to find these labs at independent schools and VOTech schools. Things happened as I have stated. The lav sink at a customers house was as I stated. Just because it isn't in your book, doesn't mean that it can't be real.
> Also note...some of the stuff you may find in the IPC code is wrong. Some is correct...some is not. Many other plumbers will agree with me on that one too.


I won't...:no:

You simply did not find the problem that the vent was masking...:whistling2:

TM Dat You?


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## Redwood (Sep 8, 2008)

Plumber3653 said:


> By the way. Can any IPC or UPC specialists explain how having a house trap on a building and fixture traps is considered "double-trapping"?
> All of these years I thought that I knew what it was, then the IPC came along and redefined it.
> All these poor people with fixture traps and house traps living peacefully without knowing the imminent danger that could be lurking on their double-trapped household.
> This should be interesting.


I can't explain why it isn't considered to be a double trap..

Because it isn't....

There is a vent placed before the house trap which equalizes the pressures so drainage will properly occur. It therefore is not a double trap.:whistling2:

TM Dat You?


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## Plumber3653 (May 5, 2010)

Thanks for agreeing, Redwood. I never understood why the IPC calls it double trapping either. House traps are forbidden by the IPC for this reason unless a local authority requires them.


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## nhmaster3015 (Aug 5, 2008)

I'm beginning to get that Master feeling :whistling2:


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## Plumber3653 (May 5, 2010)

They were all exposed and solved by venting. No problem was masked or it would have still existed after venting was installed.


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## Plumber3653 (May 5, 2010)

You should have had that feeling a long time ago.


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## nhmaster3015 (Aug 5, 2008)

I like to assume the best in folks. Sometimes I am wrong :thumbsup:


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## SlickRick (Sep 3, 2009)

Plumber3653 said:


> You should have had that feeling a long time ago.


*Hello! Introduction Requested* 
An intro is requested from all new members. In case you missed it, here is the link. http://www.plumbingzone.com/f3/.

The PZ is for Plumbing Professionals ( those engaged in the plumbing profession)

Post an intro and tell our members where you are from, yrs in the trade, and your area(s) of expertise in the plumbing field.

This info helps members who are waiting to welcome you to the best plumbing site there is.

We look forward to your valuable input.


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## Redwood (Sep 8, 2008)

Plumber3653 said:


> You should have had that feeling a long time ago.





Redwood said:


> I won't...:no:
> 
> You simply did not find the problem that the vent was masking...:whistling2:
> 
> TM Dat You?


^^^^^^^^^^^^^^^^^
I Did... Look Up! :laughing:


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## Plumber3653 (May 5, 2010)

Okay, looked up. Saw SlickRick post. Saw nhmaster3015 post. And now what? Is there some secret handshake that I need to learn? Must have been a good one.


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## nhmaster3015 (Aug 5, 2008)

Not to change the subject but do any of you guys know anything about proxy servers? :laughing:


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## Plumber3653 (May 5, 2010)

Awww, I get it. You told on me. Guess ya got me there. lol. Whew! I was worried that my zipper was down and my plumbing was exposed.


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## Plumber3653 (May 5, 2010)

Do you mean "what are they" or " are there any good proxy servers out there"?


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## Plumber3653 (May 5, 2010)

lol


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## SlickRick (Sep 3, 2009)

TM, Is that you buddy?


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## nhmaster3015 (Aug 5, 2008)

When you get down to it, this is America and in America every American has the right to think and pretty much say whatever they want to. So.... anyone that wants to believe that vents cause poor draining is more than free to carry on. :thumbsup:


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## 6th Density (Nov 29, 2010)

Maybe I can find a happy medium for everybody.

http://www.sovent.com/downloads/Sample Sovent1.pdf


:thumbup:


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## easttexasplumb (Oct 13, 2010)

The only reason vents exist is to give a topic to debate about.


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## BROOKLYN\PLUMB (May 21, 2010)

What if we find a happy middle ground and vent in 1/2" pex

Sent from my EVO 4G using Plumbing Zone


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## 6th Density (Nov 29, 2010)

BROOKLYN\PLUMB said:


> What if we find a happy middle ground and vent in 1/2" pex
> 
> Sent from my EVO 4G using Plumbing Zone



Good idea. And with pex you could bend it in the shape of an "S" and call it a "S" vent. That will get code writers going...


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## BROOKLYN\PLUMB (May 21, 2010)

You also don't have to worry about freezing or uv damage 
I'm going to check this out on my next selfinspect job

Sent from my EVO 4G using Plumbing Zone


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## SlickRick (Sep 3, 2009)

6th Density said:


> Maybe I can find a happy medium for everybody.
> 
> http://www.sovent.com/downloads/Sample Sovent1.pdf
> 
> ...


I have worked 2 projects using Sovent systems, they drive a conventional thinking plumber crazy. The are made 30 mi. from here, but I have never seen on used in Texas.


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## U666A (Dec 11, 2010)

Just googled "sovent"... Looks like a load of hooey to me. I'll read more into it as I only took a quick glance, but that's the thing about first impressions; you only get one. Seemed to be a pile of technical jargon on their site that more or less danced around what it actually is.

Hey Rick, would you mind shining some light for me or perhaps forwarding me some literature that is more helpful?


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## SlickRick (Sep 3, 2009)

U.A.til.I.die said:


> Just googled "sovent"... Looks like a load of hooey to me. I'll read more into it as I only took a quick glance, but that's the thing about first impressions; you only get one. Seemed to be a pile of technical jargon on their site that more or less danced around what it actually is.
> 
> Hey Rick, would you mind shining some light for me or perhaps forwarding me some literature that is more helpful?


Here is their site. If you have any questions, ask and I will try to answer them. There are no individual vents on this system. The distance from the stack to termination is increased dramatically. A lav. for example, is just turned up and out of the wall, with no individual vent.
http://www.sovent.com/about.htm


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## U666A (Dec 11, 2010)

SlickRick said:


> Here is their site. If you have any questions, ask and I will try to answer them.
> http://www.sovent.com/about.htm


Thanks Rick, I'll check it out.


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## easttexasplumb (Oct 13, 2010)

Was this sovent discussed in cont Ed few years back


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## SlickRick (Sep 3, 2009)

easttexasplumb said:


> Was this sovent discussed in cont Ed few years back


I do mine by correspondence. I don't remember.


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## 6th Density (Nov 29, 2010)

They are in about 50% of the condo's out here on the beach.
I've never worked a job site with this system, so I don't know that much about them. But from what other plumbers around here, they say they work just the same as combo waste and vent stacks.


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## SlickRick (Sep 3, 2009)

Here is a good article on how the sovent system works.

http://www.pmengineer.com/CDA/Archives/edc95d5472298010VgnVCM100000f932a8c0


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## jeffreyplumber (Dec 7, 2009)

U.A.til.I.die said:


> By using a wye 45 you exceed the maximum slope on the trap arm and essentially starve the vent. San tee required here by code.


This too is how I was "taught" It is how install a system as well. However I disagree that is not legal to use a combi on a vertical instead of the santee or heel outlet comonnly used here is why I belive this.... Acording to UPC 2000 code ( my latest addition) read as follows.. 1002.4 "the vent pipe opening from a soil or waste pipe, except for water closets and similar fixtures shall not be below the weir of the trap... 
Now since the trap of a w/c is up above the floor and the santee is far below the floor whats the differance if use a santee or a combi? The code clearly lists a w/c as an example of an exception. In practice I challenge any sphoning that could occur simply by using a combi instead of a santee on a w/c now for a tub or shower ok santee only. I never use a combi in this fasion but come on there is no reason it aint going to work just fine I just dont want to get in an argument with every one who thinks they got it all figured out . We get taught to do things a certain way and belive theres a good reason for them well suprise we often dont have good basis just know thats the way its "supposed to be"


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## easttexasplumb (Oct 13, 2010)

jeffreyplumber said:


> This too is how I was "taught" It is how install a system as well. However I disagree that is not legal to use a combi on a vertical instead of the santee or heel outlet comonnly used here is why I belive this.... Acording to UPC 2000 code ( my latest addition) read as follows.. 1002.4 "the vent pipe opening from a soil or waste pipe, except for water closets and similar fixtures shall not be below the weir of the trap...
> Now since the trap of a w/c is up above the floor and the santee is far below the floor whats the differance if use a santee or a combi? The code clearly lists a w/c as an example of an exception. In practice I challenge any sphoning that could occur simply by using a combi instead of a santee on a w/c now for a tub or shower ok santee only. I never use a combi in this fasion but come on there is no reason it aint going to work just fine I just dont want to get in an argument with every one who thinks they got it all figured out . We get taught to do things a certain way and belive theres a good reason for them well suprise we often dont have good basis just know thats the way its "supposed to be"


The know direction that a cable will travel, thats one of the differences.


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## U666A (Dec 11, 2010)

jeffreyplumber said:


> This too is how I was "taught" It is how install a system as well. However I disagree that is not legal to use a combi on a vertical instead of the santee or heel outlet comonnly used here is why I belive this.... Acording to UPC 2000 code ( my latest addition) read as follows.. 1002.4 "the vent pipe opening from a soil or waste pipe, except for water closets and similar fixtures shall not be below the weir of the trap...
> Now since the trap of a w/c is up above the floor and the santee is far below the floor whats the differance if use a santee or a combi? The code clearly lists a w/c as an example of an exception. In practice I challenge any sphoning that could occur simply by using a combi instead of a santee on a w/c now for a tub or shower ok santee only. I never use a combi in this fasion but come on there is no reason it aint going to work just fine I just dont want to get in an argument with every one who thinks they got it all figured out . We get taught to do things a certain way and belive theres a good reason for them well suprise we often dont have good basis just know thats the way its "supposed to be"


Yes, I'm not sure if I listed an apology for that post yet, as I meant to. You are absolutely correct in that this does apply to most fixtures, wc's are excluded. Thanks for clearing that up. Code book is in the car and there's 8" of snow out there otherwise I'd state a specific code reference.

On every test I ever took in school it asked for the 10 fixture waste requirements for a fixture with a p-trap and the 7 that are unique to fixtures requiring siphonic action.

Please don't ask me to list them as they're buried in a binder in the basement somewhere.

But total fall not to exceed inside diameter of minimum sized trap arm.... Was definitely specific to those fixtures with a p-trap.


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## 6th Density (Nov 29, 2010)

SlickRick said:


> Here is a good article on how the sovent system works.
> 
> http://www.pmengineer.com/CDA/Archives/edc95d5472298010VgnVCM100000f932a8c0




This article puts in words the best dynamics of how venting and drainage works that most plumbers don't comprehend and yet is why we are having this debate.
FROM THE ARTICLE 
*"The Stack *

Flow through a vertical stack will cling to the interior wall surface and proceed downward in a swirling motion, leaving the center portion as an open airway. As long as this airway exists, there exists a balance of pressures within the stack. Left uncontrolled, the flow will increase in speed to a point known as terminal velocity and meet sufficient air resistance to flatten out until it forms a complete cross-sectional blockage of the tube. The resulting slug of water can create significant positive and negative pressures ahead and behind the flow. These pressures may cause trap seal failures through induced siphonage and/or blowback. The Sovent system eliminates the formation of the "hydraulic plug" and maintains a core of air throughout the vertical stack."

ALSO

*"Horizontal Branches and Run-outs *

The horizontal branches and run-outs connect to the plumbing fixture and transport waste to the Sovent stack. In this area, the liquid flow remains on the bottom portion of the pipe and venting occurs in the top portion. Sovent branch sizing criteria allocate approximately 75% of the cross-sectional area for venting purposes. Sovent branch design remains the key to flexibility, and the developed length limitations that exclude additional re-vent piping far exceed those of "conventional" systems. Two-inch and three-inch pipes may extend up to 15 feet from the stack, while a four-inch pipe is permitted to extend to 27 feet. The branch size may telescope, allowing a possible run-out of 57 feet without a return vent pipe. Developed length is determined by measuring along the centerline of all horizontal piping located in the ceiling and/or wall space. The vertical drop distance is not included in the calculation."


This relates to the actual beginning thread topic. In Florida code (through table 706.3) a san tee or wye combo when used for a horizontal to vertical change in connection is allowed as long as the pipe is size correctly and as long as you follow the back to back toilet protocol.

Point being...
WATER wants to fall and hug all at the same time.


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## SlickRick (Sep 3, 2009)

Venting 202. Do we need all the vents we add? No. They are established practices that we use. Fewer well placed vents would break the pressures and achieve the same results.


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## nhmaster3015 (Aug 5, 2008)

SlickRick said:


> Venting 202. Do we need all the vents we add? No. They are established practices that we use. Fewer well placed vents would break the pressures and achieve the same results.


Yes and that philosophy is evident in the newest incarnations of the IPC and the UPC. It wasn't that long ago that wet venting was pretty much unheard of. Now, everybody wet vents. Makes you wonder if some of the change is the result of material cost.


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## nhmaster3015 (Aug 5, 2008)

I am going to upload a video of a typical lav draining 5 gallons of water. First through a vented P trap and then through an unvented P trap. The demonstration is timed. You can all begin placing your bets now. :thumbup:


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## stillaround (Mar 11, 2009)

Dont forgit....septic tanks tend to not release air like a city sewer and an extra vent in that scenario isnt so stupid....particularly with sudsing issues and septic...otherwise laws of physics,.. mass, gravity, and flow are working vent or not...


Holy cow ....talk about late ..this is post 111.....


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## 6th Density (Nov 29, 2010)

nhmaster3015 said:


> Yes and that philosophy is evident in the newest incarnations of the IPC and the UPC. It wasn't that long ago that wet venting was pretty much unheard of. Now, everybody wet vents. Makes you wonder if some of the change is the result of material cost.


I was taught by an old boss that wet ventings main purpose was to help protect the inside of cast iron pipe. It helps stabilize a moist environment inside the pipe. Basically a cast iron pipe will flake, rust, ultimately deteriorate faster if it's continuously transitioning from wet to dry to wet to dry.
Since this isn't an issue with pvc and cpvc, he told me that dry venting is really no big deal except for those darn pesky inspectors.

Anyone wanna "Myth bust" this theory, because I don't know I'm just asking?


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## jeffreyplumber (Dec 7, 2009)

Never heard of "SOVENT" Different type of waste and vent system?


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## SlickRick (Sep 3, 2009)

jeffreyplumber said:


> Never heard of "SOVENT" Different type of waste and vent system?


Sovent is an engineered system.

They are mainly used in hotels.


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## BROOKLYN\PLUMB (May 21, 2010)

6th Density said:


> I was taught by an old boss that wet ventings main purpose was to help protect the inside of cast iron pipe. It helps stabilize a moist environment inside the pipe. Basically a cast iron pipe will flake, rust, ultimately deteriorate faster if it's continuously transitioning from wet to dry to wet to dry.
> Since this isn't an issue with pvc and cpvc, he told me that dry venting is really no big deal except for those darn pesky inspectors.
> 
> Anyone wanna "Myth bust" this theory, because I don't know I'm just asking?


I think I posted that that was a secondary benefit definitely my work is 99% cast iron and you can see those affects when improper or no venting

Sent from my EVO 4G using Plumbing Zone


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## Redwood (Sep 8, 2008)

nhmaster3015 said:


> I am going to upload a video of a typical lav draining 5 gallons of water. First through a vented P trap and then through an unvented P trap. The demonstration is timed. You can all begin placing your bets now. :thumbup:


Redwood goes all in on "Tie" :laughing:


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## nhmaster3015 (Aug 5, 2008)

Ok so here it is. The average times for vent vs unvented run about 17 to 20 seconds for both. We actually ran the scenario 10 times for each and there was never anymore than a 3 second variation. Just for kicks we then changed the trap to an S trap and it also drained in about 20 seconds. Finally we pushed a rag down the vent pipe until it was just above the san tee inlet to simulate a possible clog, again with the same 20 second drain time. Clearly venting or not venting the trap makes no difference on the amount of time it takes to drain the fixture so........ given that the plumbing in a house was properly installed and has not been altered or changed, a slow drain is going to be caused by a blockage in the drain, not the vent. While I'm at this though, I often hear of drain guys that climb up on the roof and cable the vent. In most houses most of the vents are all tied back into the main VTR so how in gods name do they have any clue where their cable is going? It is almost never a straight shot.


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## Plumberman (Jul 7, 2008)

nhmaster3015 said:


> Ok so here it is. The average times for vent vs unvented run about 17 to 20 seconds for both. We actually ran the scenario 10 times for each and there was never anymore than a 3 second variation. Just for kicks we then changed the trap to an S trap and it also drained in about 20 seconds. Finally we pushed a rag down the vent pipe until it was just above the san tee inlet to simulate a possible clog, again with the same 20 second drain time. Clearly venting or not venting the trap makes no difference on the amount of time it takes to drain the fixture so........ given that the plumbing in a house was properly installed and has not been altered or changed, a slow drain is going to be caused by a blockage in the drain, not the vent. While I'm at this though, I often hear of drain guys that climb up on the roof and cable the vent. In most houses most of the vents are all tied back into the main VTR so how in gods name do they have any clue where their cable is going? It is almost never a straight shot.
> 
> Video Link: http://www.youtube.com/watch?v=vnbuoy4IYl8


Why in the hell would they rod through a 3 or 4 inch vent if that's the only vent above a bathroom? That's just a waste of time

I'll rod the vent if I'm working on a lav that is on opposie side of bathroom from toilet and has it's own vent


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## Plumber3653 (May 5, 2010)

Nice job on the video nhmaster and I agree with your statement about clogs and augering through vents. I appears that you have some time on your hands so maybe try this one out. It will simulate real life scenarios as opposed to lab situations that are predictable,
Set up a 3" stack with the bucket underneath.
Have a 3"x1 1/2" tee branch off horizontally about 8 feet with 1/2" of fall.
At the end attach p-trap. No tee at all to plug up, just straight pipe to the trap.
Water test as before with timer.
Cut approx. 1 foot behind trap and install tee on its back with a vent.
Repeat test with timer.
Before seeing your video I could visualize the test that you described in an earlier post and true to what I thought, it was all short pipe with predictable results. Humor us all and try the piping arrangement as I described. 
If only all plumbing systems were simply one solitary sink with a total of about 5 feet of plumbing.


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## nhmaster3015 (Aug 5, 2008)

I can go you one better. How about 30 feet of three inch at 1/8 ipf with an elbow and a toilet on top of that. No vent whatsoever. Toilet flushed perfectly every time. I will try your scenario next week if I get a chance. Pretty busy though, it's Skills competition week so the students are pretty focused on their practice.


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## Plumber3653 (May 5, 2010)

Also, I should add that the drain should have a pop-up drain assembly and an 1 1/4" drain w/tailpiece into the trap.
That would be the best way to duplicate the scenario that I described that was the possible inspiration for your lab example.
What I learned in a lab in science class in 9th grade. Mr. Lucas said, " In labs we create predictable results. In real life, anything could happen."


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## Plumber3653 (May 5, 2010)

nhmaster3015 said:


> I can go you one better. How about 30 feet of three inch at 1/8 ipf with an elbow and a toilet on top of that. No vent whatsoever. Toilet flushed perfectly every time. I will try your scenario next week if I get a chance. Pretty busy though, it's Skills competition week so the students are pretty focused on their practice.


That isn't "one better". Sorry. I would hope it would flow. The volume in relation to the pipe size allows air above the flow line. There is also enough air to allow the trap to reseal without a vent. Now of you put that toilet on a two inch horizontal branch 30 feet long and repeated the test with and without a vent, you would see something. But we don't put toilets on 2" and we also give toilets exception in codes due to it's design.
Since my initial analogy, that has been the focus of much debate, the factor that is being missed (as well as my bathroom group venting story) is volume in relation to pipe size.
The straw was full, the bathroom group was at max. volume the customers sink was full as well as the horizontal drain.
You see, the facts are the facts, the real life is the real life situation.
You will create a desired result to promote your belief, whether you realize it or not.
You will argue only what you know without giving the benefit of the doubt to another possible scenario. People used to believe the Earth was flat and monsters lived on the edges of the abyss.
I have agreed with all of your ideas with only one exception. 
You cannot compare a siphoning effect to a venting effect and also relate it to an unvented downstream drain. It is comparing apples, oranges and pears. You promote the similarities and ignore the differences and in some cases vice versa.


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## Plumber3653 (May 5, 2010)

Really curious on this one, nhmaster. In your video demonstration the water drained from the container, through the trap and into the bucket. After the water finished draining from the unvented trap, did it still have a trap seal? If I have the time I will duplicate your lab scenario (using the video to be as precise as possible) or you can tell us. If the container drained and the trap wasn't vented but kept a trap seal, then you would have proved that vents are not necessary at all in plumbing. Even to keep a trap seal.
My money (and Redwood should ante up on this,too) is on the trap. It will have water in it and keep the trap seal, even with the vent capped. 
And I already know why it will before the results are in. :whistling2:


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## Plumber3653 (May 5, 2010)

As I've always said. Most guys blame a vent on a clogged drain and it's not. BTW, if you showed a 3 second difference in drain time isn't that a difference? So, you kinda proved my point. And for the last time I will repeat this...I AGREE THAT CLOGS ARE MISTAKEN FOR VENTING ISSUES AS MOST PLUMBERS WILL ALSO AGREE.


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## nhmaster3015 (Aug 5, 2008)

Set up a 3" stack with the bucket underneath.
Have a 3"x1 1/2" tee branch off horizontally about 8 feet with 1/2" of fall.
At the end attach p-trap. No tee at all to plug up, just straight pipe to the trap.
Water test as before with timer.

That scenario would of course be an illegal one because we will be exceeding the trap to vent distance, however distance won’t make a difference.

What I learned in a lab in science class in 9th grade. Mr. Lucas said, " In labs we create predictable results. In real life, anything could happen."

So we are throwing out a couple thousand years of proven scientific experimentation that has lead to thousands and thousands of provable results?

The volume in relation to the pipe size allows air above the flow line. There is also enough air to allow the trap to reseal without a vent. Now of you put that toilet on a two inch horizontal branch 30 feet long and repeated the test with and without a vent, you would see something. But we don't put toilets on 2" and we also give toilets exception in codes due to it's design.

Why do we need air above the flow line to make the fixture drain? Remember we are talking about draining not trap siphonage.

volume in relation to pipe size.
The straw was full, the bathroom group was at max. volume the customers sink was full as well as the *horizontal drain*.

Why was the horizontal drain full? If the horizontal is properly sized to the DFU it should at no time be full unless there is a blockage downstream. Again the problem is the piping not the vent.

You will create a desired result to promote your belief, whether you realize it or not.
You will argue only what you know without giving the benefit of the doubt to another possible scenario. People used to believe the Earth was flat and monsters lived on the edges of the abyss.
I have agreed with all of your ideas with only one exception.

I did not “create” anything at all that is not and has not been normal plumbing practice for over a hundred years. What I created can be found in hundreds and thousands of homes. Other scenarios are only going to prove that properly piped, drains do not need vents in order to drain. 

As I've always said. Most guys blame a vent on a clogged drain and it's not. BTW, if you showed a 3 second difference in drain time isn't that a difference? So, you kinda proved my point.

The 3 seconds holds for all test runs both with and without a vent. It’s a margin of error and not consistant.

I will re- set the demonstration when I get time. However, you say the "straw is full" How does the straw get full unless the drain is plugged down stream? Remember that the argument here is predicated on the piping being properly installed and sized in the first place. As for the trap still having water in it, yes it does but remember we are not talking about trap siphoning in this case and in fact when we run the test using an S-Trap, 9 times out of 10 it does not completely siphon the trap either. We talk alot about trap siphonage but in reality siphonage does occure but not every time. My own house has 100 year old plumbing and every lav has an s trap. I don't think they have siphoned twice in 15 years.


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## nhmaster3015 (Aug 5, 2008)

OK so this is set up exactly like you wanted. Wall hung lav with 1 1/4 pop up into an 1 1/4 p trap. 10' of 1 1/2 pvc run at 1/2 ipf pitch to a 3" x 1 1/2 san tee. Time to drain without a vent near the lav 11 seconds. Then we added an 1 1/2 vent near the lav and ran it again. Time to drain same thing 11 seconds. We ran this about 10 times both ways and were consistantly at 11 seconds for the sink to drain. So though it's not technically "real world" it's pretty darn close. The only thing missing would be the clog or sag that's in the original house :laughing:


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## Plumber3653 (May 5, 2010)

Well, I am very impressed. It seems that you are absolutely correct. I was completely mistaken that vents have anything to do with anything else but the fixture trap. Your demonstrations are designed without error and show that my ideas on venting and drainage are faulted. You have clearly understood all of my statements and posts without any misinterpretation and have rebutted them in a diplomatic manner that enlightens me as to how I have unjustly persecuted you for your statements and posts.
I hope that others who have had the same thoughts as I have will also be open to these age old ideas and not be fooled as I was. 
Your lessons here will be a useful tool for plumbers who visit this site in the future who do not fully understand the reasons for and uses for venting in a plumbing system.


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## Plumber3653 (May 5, 2010)

Maybe you can help me with this question. I'm sure one of your students had to have asked it in the past. Not controversial, just asking for the reasoning behind the code.
If I individually vent all of my fixtures after the trap and take every vent outside independently, then why do I still need a stack vent? To continue the stack, undiminished in size, from the building drain through the roof seems redundant, right?
All of the traps are vented yet the same codes that state that vents are only for traps will still require a stack vent for what?
The vertical stack and the building drain is not a trap. 
All of the traps are vented.
Somebody should mention this to the people who write the rules.
Can anybody tell me why?


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## SlickRick (Sep 3, 2009)

More vents = more pipe being sold. If builders are the lobbyist, less vents. If pipe manufactures are the lobbyist, more vents.


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## U666A (Dec 11, 2010)

SlickRick said:



> More vents = more pipe being sold. If builders are the lobbyist, less vents. If pipe manufactures are the lobbyist, more vents.


Cash grab conspiracy theory!

Sent from my iPhone using PlumbingZone


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## Plumber3653 (May 5, 2010)

Could be, could be. So the people who write the books can be influenced by the people who have a financial interest. So the information is also corrupted. Hmmmm.


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## SlickRick (Sep 3, 2009)

Just the truth on how code bodies are influenced.


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## Plumber3653 (May 5, 2010)

Sometimes it's not what I say, but how I say it and sometimes how I say it doesn't translate well through text. I knew what you were saying, Rick.


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## nhmaster3015 (Aug 5, 2008)

Plumber3653 said:


> Maybe you can help me with this question. I'm sure one of your students had to have asked it in the past. Not controversial, just asking for the reasoning behind the code.
> If I individually vent all of my fixtures after the trap and take every vent outside independently, then why do I still need a stack vent? To continue the stack, undiminished in size, from the building drain through the roof seems redundant, right?
> All of the traps are vented yet the same codes that state that vents are only for traps will still require a stack vent for what?
> The vertical stack and the building drain is not a trap.
> ...


 
Now that depends on who's code you are under. The UPC still requires what we always called a main vent but the IPC abandoned that a long time ago and simply says that a drainage system shall have at least one vent through the roof that is 1/2 the size of the building drain which in most residential cases would be 2" and that vent can pretty much come off the system anywhere.


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## Walt (Mar 12, 2011)

vent wise the commode is a disaster no matter how you look at it because it has an integral trap. so for it to technically be proprely vented it would have to be lowered to were the crown wier would not rise above the vent at the tee.obviously not possible. so the real question is why a tee or combo. i have seen both situations and have heard both sides.around here they stopped using tees because they had trouble with rodding going across to other side.just as they eliminated using double wyes on the horizontal plane becauuse waste was crossing i did not believe it till i saw it..the 2006 ips code and commentary says both are allowable under distance limitations.at least thats i how read it.


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## nhmaster3015 (Aug 5, 2008)

Walt said:


> vent wise the commode is a disaster no matter how you look at it because it has an integral trap. so for it to *technically be proprely vented* it would have to be lowered to were the crown wier would not rise above the vent at the tee.obviously not possible. so the real question is why a tee or combo. i have seen both situations and have heard both sides.around here they stopped using tees because they had trouble with rodding going across to other side.just as they eliminated using double wyes on the horizontal plane becauuse waste was crossing i did not believe it till i saw it..the 2006 ips code and commentary says both are allowable under distance limitations.at least thats i how read it.


Define "properly vented" Since a toilet has an integral S trap and is designed to be a self siphoning fixture, it needs no vent at all. IPC recognizes this and allows fixture to vent distance to be "unlimited" under to 06 and later editions. As far as the recieving fitting again the IPC will allow you to use a san tee. combo or wye to recieve the discharge with the exception that you can not use a san cross for back to back toilets that use flushometers. Good plumbing practice should keep you from using a double san tee for back to back toilets even if they are normal flush because of course, running a cable is a real *****.


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## Lifer (Nov 23, 2010)

Plumber3653 said:


> Maybe you can help me with this question. I'm sure one of your students had to have asked it in the past. Not controversial, just asking for the reasoning behind the code.
> If I individually vent all of my fixtures after the trap and take every vent outside independently, then why do I still need a stack vent? To continue the stack, undiminished in size, from the building drain through the roof seems redundant, right?
> All of the traps are vented yet the same codes that state that vents are only for traps will still require a stack vent for what?
> The vertical stack and the building drain is not a trap.
> ...


 
The 3" mandatory vent in a home helps vent the sewer lines in the street, Not so important in a home on a septic but when you are on a City sewer line the venting of gasses and pressure is done through everyone's home via the 3" vent ( or 4" depends where you are ) That is why you are not allowed to use a normally closed back water valve on the main line into a home , You must use a normally open back water valve so the street can still vent ... but in the case of a back up the home will still be protected.

Lifer...


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## nhmaster3015 (Aug 5, 2008)

Plumber3653 said:


> Maybe you can help me with this question. I'm sure one of your students had to have asked it in the past. Not controversial, just asking for the reasoning behind the code.
> If I individually vent all of my fixtures after the trap and take every vent outside independently, then why do I still need a stack vent? To continue the stack, undiminished in size, from the building drain through the roof seems redundant, right?
> All of the traps are vented yet the same codes that state that vents are only for traps will still require a stack vent for what?
> The vertical stack and the building drain is not a trap.
> ...


The stack goes back to the days when it was believed that we needed it to vent the main due to sewer gas from the city side of things. A question that often came up was " if the system is on a private septic then why do we still need the stack" good question and eventually the plumbing code was changed to reflect new methods. You have to remember that wet venting as a concept has been around for a hundred years or so but was only acceptable fairly recently in plumbing history. I hate to believe that manufacturers and such have something to do with the code but I fear it is so and has been for a long time. Why else would we be allowed to install such things as AAV's and waterless urinals?


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## jeffreyplumber (Dec 7, 2009)

*Cash grab conspiracy*



U.A.til.I.die said:


> Cash grab conspiracy theory!
> 
> Sent from my iPhone using PlumbingZone


Heck yea. Copper (CDA) doesent lobby code and building officials to allow pex and plastic do they? I hope the U. A. isnt helping to allow pro-press. Everyone has their agenda and to think that every thing plumbing is for the betterment of all is wrong. Builders want cheap material cheap labor. Plastic companys want to sell plastic and so on.


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## Redwood (Sep 8, 2008)

Plumber3653 said:


> Could be, could be. So the people who write the books can be influenced by the people who have a financial interest. So the information is also corrupted. Hmmmm.


Thats what happens when you mix politics and plumbing...
It all goes to shiot...


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## SlickRick (Sep 3, 2009)

jeffreyplumber said:


> Heck yea. Copper (CDA) doesent lobby code and building officials to allow pex and plastic do they? I hope the U. A. isnt helping to allow pro-press. Everyone has their agenda and to think that every thing plumbing is for the betterment of all is wrong. Builders want cheap material cheap labor. Plastic companys want to sell plastic and so on.


Or CI. While I was chief P.I. in Longview we were all CI. Tyler Pipe and the Cast Iron Soil Pipe Institute got word that I was going to except the use of PVC. A rep from both came bearing gifts and took me to the swankiest rest. in Longview, one that had more spoons and forks than I knew what to do with. They were armed with some misinformation on PVC installation standards. When I corrected them on the proper installation standards, and ask them if they were trying to save the world from PVC, or sell CI, lunch was over. I got to keep some nice gifts though. Last I ever heard from them


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## jeffreyplumber (Dec 7, 2009)

Yes a lot of politics involved. We as plumbers have to try and figure out why a code tells us to do things a certain way. We get taught to do things certain way, such as venting, we think there is good reason. Then you find out they do something so different. Wow there are millions of homes that actualy have a working DWV system, their houses dont stink and the s%$&^ actualy still goes down hill. Despite not adopting UPC codes


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