90's in TPR pipe, how many are OK?

[George Sharrett]

Hello,

Is there a limit to how many 90's can be in the TPR pipe? (water heater app) I inspected a new home (11TH MO insp) and six were visible before the pipe went into the wall. The last one (barly visible) tucked behind the duct sent the pipe horizontal to the left...I figure it would take at least 3 more to get it to the outside wall where I saw it emerge. That makes, lets see...9!

I used to have a tag off of a TPRV on my desk and I am almost certain it mentioned a number of allowed 90' bends in the pipe.

Can anyone help with this?

Thanks,
George

[Erby Crofutt]

Everything I've seen said 4 but it's been awhile since I've researched it. What does the manufacturer say?

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[Mike Gault]

And you know a single length of PEX could have made all that's visible in the picture unnecessary... and would have taken 1 minute to install...

My 4 or 5 y/o code check says 4... but the MII should say similar...

[A.D. Miller]

Four, unless . . .

http://www.aaronsinspections.com/documents/WattsTPRLabelandLetter.pdf

[Vern Heiler]

George you might want to check and see if your area requires it to discharge into an air-gap within the same room. That would make the number of 90's a moot question.

[Phillip Smith]

In Code Check Plumbing third edition it says Max of 4 90 degree elbows and max length 30 ft. Manufacturer.

[George Sharrett]

Thank you all for the information.

I stated in my report that some manufactures suggest no more than 4 90's and that there no less than 9 on this pipe.

The county did not have a code reference for it. I suggested that they ask the builder to evaluate the pipe with them and if he or she said it was acceptable to get it in writing.

I suggested it was not a "best building practice" and was a possible safety issue.

George

[Jerry McCarthy]

The 4 90's and 30 foot maximum length are manufacturer's regs, not the UPC 608.5 or IRC 2803.6.1.

[Jerry Peck]

I stated in my report that some manufactures suggest no more than 4 90's


The 4 90's and 30 foot maximum length are manufacturer's regs,

As WC Jerry said, those are more than just suggestions.

Those are not "suggestions", but "must not exceed" specifications least a restriction is caused, and reducing the capacity of the valve, in which case the valve is no longer providing its rated capacity and is therefore now unrated for the installation.

[George Sharrett]

Jerry,

I appreciate your concern but this particular manufacture had no such requirements or recommendations for this valve. I did not think it was right to quote something that does not exist for this specific valve.

http://www.watts.com/pdf/ES-10L-100XL.pdf

"IMPORTANT: A relief valve functions in an emergency by discharging water. Therefore, it is essential that a discharge line be piped from the valve in order
to carry the overflow to a safe place of disposal. The discharge line must be the same size as the valve outlet and must pitch downward from the valve and
terminate at least 6"(152mm) above the floor drain where any discharge will be clearly visible. For 100DT discharge line consult your Watts agent.
IMPORTANT: INQUIRE WITH GOVERNING AUTHORITIES
FOR LOCAL INSTALLATION REQUIREMENTS"



I don't think I would have a good case if the manufacture had no such specs and the County has no code requirement concerning number of 90's. (called them this morning)

That is why I went with trying to make the case that it still was not a good idea in my mind, may be a safety concern and that if the builder said it was OK to get it in writing.

I just joined last night as I attempted to sort all this out. I am very glad to see there is a Construction / Litigation Consultant on board.

Thanks again,
George

[Jerry Peck]

I appreciate your concern but this particular manufacture had no such requirements or recommendations for this valve. I did not think it was right to quote something that does not exist for this specific valve.

http://www.watts.com/pdf/ES-10L-100XL.pdf


George,

The first part of Aaron's posted link was of the tag which came on the Watts relief valves.


http://www.aaronsinspections.com/documents/WattsTPRLabelandLetter.pdf

I have not read one of their tags in the last couple of years (shame on me) but that is a specific set of requirements for all of their temperature and pressure relief valves - at least *was* their specific requirements.

[George Sharrett]

Very interesting...

This appears to be exactly the tag I had on my desk for some time and made me question the installation.

Why would they back down or change it? I now wonder if the web site specifications differ from the actual tags on the units.

I need a trip to the plumbing supply house. I wish I had opened that link he posted last night. I would have included it in the report.

When I make it to the PSH I will add to this post what my findings were.

Thanks again,
George

[A.D. Miller]

GS: Nope, the same tag is on the new valves. I buy a new one every year just for that reason.

JP: Shame on you for slacking off on your label reading habits.:D