how many GPM (from a shower) can go thru a 2\" trap?

Bruce_9

I am installing a Grohe 3/4" shower valve and five 2.75 Gpm shower heads and body sprays. What about the drain for this hot water guzzler? How many GPM will go down a 2" trap before a lake forms in the shower? All the code books and references I have only talk about fixture units which I don't think applys here. Are there any engineers out there who know or know of real reference books that address this situation? Maybe there is a standard for school gym showers or other high volumn cases? Thanks in advance for your help.

plumber with water heater promblem

6-1-05 i have a power vent water heater to instal .with a inspector promblem the inspector says code for flew termanation has to be 10ft away from property line .manafactures say 2ft .today i ascked him to show me the code so we spent 1/2 hr looking in code book with know luck.code book direct vent b vent z vent refer to manufactures recamendatoins please help thank you

hr

The strainer is

usually the bottle neck in the flow. I know a 2" drain easily handles a garden hose at full flow Of course the P trap is properly vented?

Unvented traps can be REAL slow.

hot rod

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

PLUMBERPIERCE

Plumber with water heater problem: I'm in Mass, and can only speak for our state code. In terms of gas equipment manufacturer specifications supercede state code. Start by calling them for verification. Then present their recommendation to the inspector

Al Letellier

shower drain

I have a Moen 5 head unit in my personnal shower and even with all five going, a 2"drain handles it with no back up whatsoever. Check your local code. Here in Maine a 2" drain is all that is required, and the fixture units are described as the force exerted on a plumbing system by the flow of water from any fixture as determined on some arbitrary scale....if you know who or what "arbitrary" is, let me know.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

gerry gill

the ASPE data book

the data book #2 from american society of plumbing engineers says a drain should flow 1/2 full for best effect..at a 1/4'' pitch, 1/2 full flow on a 2'' drain is limited to 8.4 gpm...can you ''stuff'' more down it? sure..but then you mess with the air that is desired over the flow..the idea is to not have a ''slug'' of water moving down the pipe..i would recommend either two 2'' drains or one 3'' drain...hope this helps..

Mike T., Swampeast MO

Exact situation. 2" properly vented drain is more than adequate.

hr

Good info, Gerry

much better that a guess

hot rod

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Michal

since when did manufacturers codes superceed

I am totally un aware that manufacturers specs superceed state codes, I thin you are wrong wirth that. State codes are more stringenrt then any manufacturers code, and yes you should be 10'-0" away, but thats all in your states mechanical code section or might be under nfpa codes as well

Jack_21

Yeah, cool info Gerry, Thanks!!

PLUMBERPIERCE

Where did chimney venting go, who gave us fan assisted venting, sealed combustion. Pex tubing, cssr gas tubing... The manufacturers did. when the product is approved by the code and governing bodies, until its documented in the text we refer to the manufacturers specs. until just this march there was no mention of some of the products listed above in our code we followed the manufacturer's specifications. as long as the venting meets the manufacter's specs on both sides of the property line, [ie] walkways, windows , doors, forced air inlets so forth wheres the problem? The building isn't ten feet from the property line!!! curious

dasplumber

make sure you use wide mouth strainer on drain!

2" drain is fine but make sure that you use a 6" wide strainer. We have had drainage problems in the past with the smaller 3"-4" strainers. The 6" strainer is money well spent.

Bruce_9

Who makes these shower pan fittings with 6" strainers I have only ever been able to get 4" from my wholesalers?

Michal

I have never seen 6\"

but look into J.R. Smith, it might be a floor drain and not a shower drain with a brass top, thats all I can think of

Scott Denny

Code question

Bruce
In UPC territory, the first head is rated at 2 drainage fixture units (DFU)[table 7-3]. The next four heads are rated at 1 fixture unit each. Thus, you have a total of 6 DFU's. Maximum loading for a 2" trap is 4 DFU's and for a 3" trap 6 DFU's (section 702.0). Therefore, I would be required by code to put in a 3" trap and drain. In reality, most inspectors would not go to the trouble of counting DFU's, so a 2" drain would probably fly.