# Pressure relief valve hot water tank



## kid_goku (Jan 22, 2015)

Can anyone tell me if there would be any problems with this...attaching a 3/4 PVC pipe to the pressure relief valve on a residential hot water tank and using it like a drain. In other words, it's not cut off short of the floor, it runs all the way over to the sump pump. The idea was that if it leaked, it would end up there instead of the floor. However, I'm not sure if this is a problem as far as code is concerned or safety.
I am currently a plumbing apprentice, formerly in building maintenance. There I did lots of drain cleaning, fixed leaks, set fixtures, replaced cracked lines, etc. Now I'm trying to learn the more technical aspects of plumbing.


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## plumbdrum (Nov 30, 2013)

Better do a intro


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## SchmitzPlumbing (May 5, 2014)

sounds like a bunch of crap. why wouldnt you ask your boss or j-man first?


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## wharfrat (Nov 1, 2014)

I think that drain should run out to the curb at the street kid goku. Where is your introduction?


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## kid_goku (Jan 22, 2015)

I'll go post that intro right now. I got a little anxious to find out about this.


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## KoleckeINC (Oct 22, 2011)

Depending on your state, you should leave an air gap between the termination and the drain that would receive its discharge. In Illinois it's twice the diameter of the pipe. So 1.5" air gap for safety.


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## kid_goku (Jan 22, 2015)

Thanks for all the replies so far. Schmitz, no there is no crap involved. This is hot water tank, not a toilet. Has anyone ever seen anything like this done before? Typically, there is about a 3 foot pipe extending down from the relief valve and the water would shoot out onto the floor of the (basement usually). This alternative method would carry it about 8 feet over to the sump pump.


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## dclarke (Dec 22, 2012)

I wouldn't bother with it honestly. If it's piped to a sump it's easier to ignore the problem. If it's dripping there's an issue that needs fixed and if it's dripping on the floor they are more likely to fix the issue quickly.


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## kid_goku (Jan 22, 2015)

Thanks dclarke. That's what I thought. I appreciate it.


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## HonestPlumb (Jan 25, 2015)

dclarke- exactly. If it is leaking there is a pressure or (less likely) a temperature problem, it is an issue that needs to be investigated . In my state (NJ) It is illegal to run PVC from a relief valve period. It will melt and possibly collapse,thereby negating the relief valve by closing it off. We also have Thermal expansion, which then requires a Thermal Expansion tank installed. Some areas near me have 175#'s in the street.


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## pianoplumber (Apr 19, 2014)

I've said this before: Relief valve on a hot water heater is a direct connection to potable water system. Therefore, you must have an air gap at its outlet. If it is sticking down into the sump pit, you have a cross connection and possibility of contamination. Also, since it is considered part of potable water system, material used should be approved for potable water.


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## tailpiece (Jan 3, 2015)

Not gonna get you the pay raise for "going the extra mile" kiddo


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## GAN (Jul 10, 2012)

KoleckeINC said:


> Depending on your state, you should leave an air gap between the termination and the drain that would receive its discharge. In Illinois it's twice the diameter of the pipe. So 1.5" air gap for safety.


Yep on the AG, but no on the PVC. Metallic drain off a relief


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## titaniumplumbr (Jun 11, 2014)

You can use cpvc not PVC


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## bct p&h (Jan 19, 2013)

GAN said:


> Yep on the AG, but no on the PVC. Metallic drain off a relief


Metallic is a little too generic for this. Metallic could also mean steel, which is a huge no no for the outlet side of a relief valve.


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## titaniumplumbr (Jun 11, 2014)

Or titanium I'm sure I can find some to sell you


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## czplumbing (Nov 24, 2014)

Yes if its leaking or dripping you have to change the pressure valve. but what if you did a an air gap on the PVC pipe that would collect the water if their was ever a problem. this would allow the water to drain some where else instead of on the floor?


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## GAN (Jul 10, 2012)

bct p&h said:


> Metallic is a little too generic for this. Metallic could also mean steel, which is a huge no no for the outlet side of a relief valve.


UH....... new I should have included the whole code section......
*Section 890.1230 Safety Devices*
d) Relief Discharge Outlet ​3) Any piping used for discharge from the relief valve shall be of metallic material, shall comply with Appendix A. Table A (Approved Materials for Water Distribution Pipe) for potable water piping, and shall drain continuously downward to the outlet. ​*Approved Materials for Water Distribution Pipe*​ 
1)
Brass Pipe2
ASTM B 43-2009



2)
Chlorinated Polyvinyl Chloride2 (CPVC) Pipe/Tubing
ASTM D 2846/D 2846M-2009be1

ASTM F 441/F 441M-2012


ASTM F 442/F 442M-2012 
​ CSA B137.6-2009 in B137

Joints
ASTM D 2846/D 2846M-2009be1
​ CSA B137.6-2009 in B137

Solvent Cement1
ASTM F 493-2010


CSA B137.6-2009 in B137



3)
Copper/Copper Alloy Pipe2
ASTM B 42-2010


ASTM B 302-2012
AWWA C606-2011



4)
Copper/Copper Alloy Tubing2
ASTM B 88-2009



5)
Cross Linked Polyethylene2
ASTM F 876-2013a

Distribution Systems

Joints
ASTM F 877-2011a
ASTM F 1807-2012
ASTM F 1960-2012
ASTM F 2080-2012
ASTM F 2098-2008
ASTM F 2159-2011
ASSE 1061-2011
​ CSA B137.5-2009 in B137
​ 
6)
Galvanized Steel Pipe2
ASTM A 53-2012
AWWA C606-2011



7)
Poly Butylene (PB) Pipe/Tubing2

​ 

CSA B137.8-2009 in B137


8)
Polypropylene Pipe2
ASTM F 2389-2010


9)
Polyvinyl Chloride (PVC) Pipe2, 3
ANSI/NEMA Z535.1-2006 (R2011)
ASTM D 1785-2012
​ ​ ASTM D 2241-2009


ASTM D 2672-2009


CSA B137.3-2009 in B137

Joints
ASTM D 2855-2010
ASTM F 441/F 441M-2012


CSA B137.2-2009 in B137


CSA B137.3-2009 in B137

Primer
ASTM F 656-2010

Solvent Cement1
ASTM D 2564-2012


CSA B137.3-2009 in B137



10)
Stainless Steel Pipe2
ASTM A 312/A 312M-2012
ASTM A 403/A 403M-2012
ASTM A 511/A 511M-2012



11)
Welded Copper Water Tube2
ASTM B 447-2012a WK, WL and WM



12)
Solder
ASTM B 32-2008







Agency Notes: 

1 Solvent cement must be handled in accordance with ASTM F 402-1988. 
2 Water distribution pipe must meet the appropriate NSF standard for potable water. Plastic shall be rated at 160 psi at 73.4 degrees Fahrenheit.
3 Use for cold or tempered water only.
4 ASME B.1.20.1-1983.
5 Safety Color.


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## Redwood (Sep 8, 2008)

HonestPlumb said:


> dclarke- exactly. If it is leaking there is a pressure or (less likely) a temperature problem, it is an issue that needs to be investigated . In my state (NJ) It is illegal to run PVC from a relief valve period. It will melt and possibly collapse,thereby negating the relief valve by closing it off. We also have Thermal expansion, which then requires a Thermal Expansion tank installed. Some areas near me have 175#'s in the street.


:thumbup:

Yep PVC isn't good with hot water and the leaking says there is a pressure or thermal expansion problem which requires correction...


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