# Relief Valve Piping?



## PLUMBER_BILL (Oct 23, 2009)

GRANTED ... Codes require that relief valve discharge must not be trapped. IE: The closed post this A.M. by the HVAC Guy.

But are there any alternatives? Personally I would not want to be standing in line of the 3/8" hole. 

eg.


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## Ron (Jun 12, 2008)

PLUMBER_BILL said:


> GRANTED ... Codes require that relief valve discharge must not be trapped. IE: The closed post this A.M. by the HVAC Guy.
> 
> But are there any alternatives? Personally I would not want to be standing in line of the 3/8" hole.
> 
> eg.



Not under UPC Code


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## TheMaster (Jun 12, 2009)

Does the UPC require relief valves to be installed per the manufacturers instructions AND meet the UPC code? Both can be accomplished.


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## Ron (Jun 12, 2008)

UPC says it has to be piped to the outside or to an indirect waste receptor.


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## TheMaster (Jun 12, 2009)

Ron The Plumber said:


> UPC says it has to be piped to the outside or to an indirect waste receptor.


So you can pipe it with anything you want..even pvc or any size?


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## Ron (Jun 12, 2008)

Out of the pan PVC direct from water heater CPVC


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## TheMaster (Jun 12, 2009)

Ron The Plumber said:


> Out of the pan PVC direct from water heater CPVC


 Ok sounds good. Try this next time you install one....hold open the relief valve for about 10 minutes and see if the pan will take it out as fast as it comes in. I assume your pan drain is 1" gravity and the discharge pipe is 3/4. I think they should go out independent but hey I dont write the code.


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## TheMaster (Jun 12, 2009)

Heres how my code works. You can pipe a water heater pan in 1" but the relief line must go out independent. If you pipe the water heater pan drain with 1.5" pipe you can install a combo in the drain pan piping and dump the relief line down into it but it still cant dump directly into the pan itself.


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## ESPinc (Jul 18, 2009)

Ron The Plumber said:


> Out of the pan PVC direct from water heater CPVC


Here we have to use 1" cpvc for the pan drain,but most of our heaters are installed in the garage, so no pan is required as long as the garage is lower than the home floor elevation


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## Tankless (Jun 12, 2008)

I do 1" PVC from the pan and 3/4 copper from the discharge to the exterior terminated between 6 & 24" above the grade. I don't know whatthe distance req's for the pan drain is. There may not be a tee - a valve of any kind and the ID may not get reduced. I also seem to remember that there may not be threads at the termination point of the relief line. OH..OH, the discharge line may not be located in an area where damage can occur should the valve release!


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## TheMaster (Jun 12, 2009)

Tankless said:


> I do 1" PVC from the pan and 3/4 copper from the discharge to the exterior terminated between 6 & 24" above the grade. I don't know whatthe distance req's for the pan drain is. There may not be a tee - a valve of any kind and the ID may not get reduced. I also seem to remember that there may not be threads at the termination point of the relief line. OH..OH, the discharge line may not be located in an area where damage can occur should the valve release!


 We do no closer than 2" but not more than 6" from the ground to terminate the relief discharge.


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## Ron (Jun 12, 2008)

Here 3/4 is all you need unless you have more then one water heater connected to the line, then it goes to 1" where 2nd heater connects. I don't write the codes, I just follow the codes. You can have up to 3 water heater on a 1" drain.


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## ToUtahNow (Jul 19, 2008)

TheMaster said:


> Ok sounds good. Try this next time you install one....hold open the relief valve for about 10 minutes and see if the pan will take it out as fast as it comes in. I assume your pan drain is 1" gravity and the discharge pipe is 3/4. I think they should go out independent but hey I dont write the code.


Under the UPC it is illegal to drain a T&P valve discharge into the water heater pan.

Mark


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## Ron (Jun 12, 2008)

ToUtahNow said:


> Under the UPC it is illegal to drain a T&P valve discharge into the water heater pan.
> 
> Mark



Maybe under CA UPC but here as long as the pan is drained to the outside water heater T&P can drain to the pan.


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## ToUtahNow (Jul 19, 2008)

Ron The Plumber said:


> Maybe under CA UPC but here as long as the pan is drained to the outside water heater T&P can drain to the pan.


Actually it is UPC 508.5 which states, _"Discharge from a relief valve into a water heater pan shall be prohibited."_

Oregon deleted 508.5 through 508.12 when they adopted the UPC so it is not in the Oregon Code but it is in the UPC.

Mark


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## Ron (Jun 12, 2008)

Oregon code is a revised copy of the UPC side by side almost identical, but not totally.


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## ToUtahNow (Jul 19, 2008)

Ron The Plumber said:


> Oregon code is a revised copy of the UPC side by side almost identical, but not totally.


I'm not sure what all of the difference are but Chapter 5 of the UPC is 55-pages long. Chapter 5 of the Oregon Plumbing Code is 4-pages long.

Mark


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## Ron (Jun 12, 2008)

Actually we call our code Oregon Specialty Code, we don't call it The UPC


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## ToUtahNow (Jul 19, 2008)

Ron The Plumber said:


> Actually we call our code Oregon Specialty Code, we don't call it The UPC


Yes I know I have a copy online. California calls ours the CPC.

Mark


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## Ron (Jun 12, 2008)

Back to what Bill was asking years ago they allowed you to run a T&P up and out if needed provided a small hole was drilled into the bottom of the 1st vertical 90 on the line, I have yet to come across one like it, that was changed very soon after it was allowed.


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## TheMaster (Jun 12, 2009)

Hey Bill i wonder what happened in or before 1987 that changed peoples minds about the line being trapped being ok?


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## Tankless (Jun 12, 2008)

Ron or Mark, do you know if this is stated in the UPC? I seem to remember the statement one half size, but I forget if it applied to this particular. As far as I knew, ANY tee was not allowed on the line. One would have to put a tee in to join the two. This could help me on a job coming up. Thx



Ron The Plumber said:


> Here 3/4 is all you need unless you have more then one water heater connected to the line, then it goes to 1" where 2nd heater connects. I don't write the codes, I just follow the codes. You can have up to 3 water heater on a 1" drain.


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## Ron (Jun 12, 2008)

Here we tie the lines together and go out with line line, so yes tee/s are allowed here, but your in CA so it could be different there.


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## Tankless (Jun 12, 2008)

Damn....I know I read it or heard it from an inspector before. I hate not remembering. Ironically enough I was called out to a job where two tankless units were installed. Both relief lines were discharged to the pan, than the pan had a 3/4" copper line to the outside. I was told the inspector made the original plumber do it this way. I got pictures of this somewhere. I asked the home owner for the permits but he said they were filed away. I wanted to talk to this winner. Shoulda seen what this moron made the guy do with the venting...... So what do ya think Ron, your ammendment or mine on the Tee being allowed?


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## Ron (Jun 12, 2008)

Allowed here as like as you increase the size by 1 pipe size 3/4" becomes 1" after the 1st heater.


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## Tankless (Jun 12, 2008)

hmmm, OK, I gotta go look it up in the CPC....this is gonna bug the hell out of me until I know one way or another. For this job, which I was talking with the HO today I was giving her my schedule next week...when gas would be off...when water will be off...etc.. and she stops me and says "you know we're getting rain all next week, don't you?" I says, we're getting what? Next week just went down the hill. I don't know how the rest of you guys do it.


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## Redwood (Sep 8, 2008)

TheMaster said:


> Hey Bill i wonder what happened in or before 1987 that changed peoples minds about the line being trapped being ok?


I would venture to guess a frozen trap that kept a T&P from discharging...

Probably causing a water heater to launch...:laughing:


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## PLUMBER_BILL (Oct 23, 2009)

Redwood said:


> I would venture to guess a frozen trap that kept a T&P from discharging...
> 
> Probably causing a water heater to launch...:laughing:


On my website is a blog. Launched water heaters.

The data came from the NAPHCC in the 70's via news paper clippings nation wide in the 60's. The booklet I had was about ready to, die so I scanned in the best and put them on my site. Feel free to copy if you want. http://inspdiy.blogspot.com/2008/12/this-blog-is-informational-and-is-part.html


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## TheMaster (Jun 12, 2009)

I'll never trap a rellief line period. In a landlocked water heater install we turn the relief line behind the heater and secure it so if it blows off nobody will be in the line of fire. If it floods the house then so be it. Nobody getting hurt is the main objective not saving property from water. This was approved by the local code dept. before anyone starts quoting any codes for me.


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## ToUtahNow (Jul 19, 2008)

Tankless said:


> Ron or Mark, do you know if this is stated in the UPC? I seem to remember the statement one half size, but I forget if it applied to this particular. As far as I knew, ANY tee was not allowed on the line. One would have to put a tee in to join the two. This could help me on a job coming up. Thx


It's not really covered but it would not make much sense to tie relief drains together.

The wording in the UPC and CPC 608.5 is _"Relief valves located inside a building __shall be provided with a drain, not smaller than the relief __valve outlet"._ 

As such you would need to assume it is possible all devices on a combined relief drain could all open at the same time. So if you combine drains you need to size your relief drain to the total of all of the drains. Using that, 2-3/4" T&Ps would require an 1 1/4" relief line which would really handle up to 7-3/4" relief lines. All of the above considered it would still not make sense to combine relief lines. In addition, most Jurisdictions will not let you combine relief lines because you cannot identify which relief valve is leaking.

Mark


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## SummPlumb (Feb 19, 2010)

You can turn a relief line up as long as there is a drip leg where you turn it up. I use a 3/4-1/2/-3/4 tee. Put a straight stop on the bottom as the drip leg. I never leave a relief line inside of a house. If it blows off, it is steam. It is under pressure when it blows off, so it can easily go up for a short run then drain out. 

It is against GA code to tie two relief lines together. But it is also illegal to S trap any fixture. So someone explain how a commode is not an S trap?


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## TheMaster (Jun 12, 2009)

SummPlumb said:


> You can turn a relief line up as long as there is a drip leg where you turn it up. I use a 3/4-1/2/-3/4 tee. Put a straight stop on the bottom as the drip leg. I never leave a relief line inside of a house. If it blows off, it is steam. It is under pressure when it blows off, so it can easily go up for a short run then drain out.
> 
> It is against GA code to tie two relief lines together. But it is also illegal to S trap any fixture. So someone explain how a commode is not an S trap?


 The dripleg is useless unless its used by the customer to drain it....then it can be left open,possibly burning sombody. Cant do that here,relief valves cant be turned up.
I cant believe your actually serious about the toielt "s" trap question.....thats basic plumbing 101. You tell me why its legal:whistling2:


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## ranman (Jan 24, 2010)

the toilet is self replenishing .


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## SummPlumb (Feb 19, 2010)

The toilet question is a joke.  I did not mean actually turning the brass relief line up. I meant you can turn the pipe and go up and out. The drip leg is there so I can diagnose the problem faster. Plus our inspectors here want them if we go up with a relief line. 

Happy Sunday to all. It is 65 degrees here. WoooHooo!


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## jeffreyplumber (Dec 7, 2009)

nEVER HEARD OF A TAND P LINE THAT GOES UP HILL, i GUESS IT USED TO BE LEGAL AND THAT THE CITY OF PHOENIX ALOWS THAT BLEED HOLE FOR SOME REASON , i CAN ONLY GUESS THAT IT IS BECAUSE ITS IMPRACTICAL TO REQUIRE COMPLIANCE ON AN EXISTING JOB.


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## ranman (Jan 24, 2010)

its not allowed anymore and i have never seen one.


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## Protech (Sep 22, 2008)

PVC is fine for a pan drain here. Same rule about the floor level though. Funny how we are supposed to be under a state wide code yet it is still different from city to city.



ESPinc said:


> Here we have to use 1" cpvc for the pan drain,but most of our heaters are installed in the garage, so no pan is required as long as the garage is lower than the home floor elevation


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