Water Heater Install Question

[SCBO1]

The GAS valve should be before the dirt leg (drip leg) on a natural gas water heater but can it be installed below the dirt leg? I can't find if this is a violation but it does not make sense to have the valve lower than the leg!

pc1

 

[fatboy]

Don't have the IFGC in front of me, but i don't believe that drip legs are addressed in the code. But yes, common sense would say the drip leg is before, and below the valve.

 

[mtlogcabin]

Drip and dirt are 2 different requirements

Short answer No

408.2 Drips.

Where wet gas exists, a drip shall be provided at any point in the line of pipe where condensate could collect. A drip shall also be provided at the outlet of the meter and shall be installed so as to constitute a trap wherein an accumulation of condensate will shut off the flow of gas before the condensate will run back into the meter.

408.3 Location of drips.

Drips shall be provided with ready access to permit cleaning or emptying. A drip shall not be located where the condensate is subject to freezing.

408.4 Sediment trap.

Where a sediment trap is not incorporated as part of the appliance , a sediment trap shall be installed downstream of the appliance shutoff valve as close to the inlet of the appliance as practical. The sediment trap shall be either a tee fitting having a capped nipple of any length installed vertically in the bottommost opening of the tee or other device approved as an effective sediment trap. Illuminating appliances, ranges, clothes dryers and outdoor grills need not be so equipped.

 

[north star]

< = =



"mtlogcabin" provided the code sections from the IFGC.

Here it is the `06 IFGC.....If it is an IRC application,

...see Section G2419, `06 IRC.

Pcinspector1,

Which is it, ...Commercial or Residential?



+ + >

 

[SCBO1]

northstar,

Residential, and the correct term i should be using is "Sediment trap" which confuses Jr. the plumber. Thinks he needs a trap, so we call it a "drip or dirt leg". They also put the tee in a horizontal line and drop the leg from the tee which does not change the gas flow direction like you should!

pc1

 

[Francis Vineyard]

I’ve heard them called “dog legs” and the gas valve are allowed to be located below the level of the sediment trap. The trap as noted should be a 90 degree change of direction from horizontal to an upwards vertical travel before the appliance connection in hopes that any heavy debris will fall into the extend well below the 90 degree elbow. Most common is the downward travel then 90 to horizontal with the valve above.

I believe all new gas valves have an inlet screen now days. Besides the odor is dirty gas available?

Francis

 

[Gregg Harris]

northstar,Residential, and the correct term i should be using is "Sediment trap" which confuses Jr. the plumber. Thinks he needs a trap, so we call it a "drip or dirt leg". They also put the tee in a horizontal line and drop the leg from the tee which does not change the gas flow direction like you should!

pc1

If you are under 2009 the change in direction no longer exist, it is the bottom most outlet so the branch outlet in a horizontal is the bottom most outlet.

 

[Francis Vineyard]

The change in direction and length of the leg is a requirement from the (GAMA) gas appliance installation guide and where none is provided the code requires "other device approved as an effective sediment trap." So it would be the AHJ call to allow a "T" without a change of direction or even a inlet screen at the valve.

2009 Code Change Proposal:

"Last code cycle sediment traps where deleted during the public comment hearings only to have a successful final action comment submitted by the Gas Appliance Manufacturers Association (GAMA) to have them reinstated. In laboratory testing sediment is sure to create a problem as GAMA asserted however for more than twenty years sediment in gas lines has not been prevalent. The gas suppliers and utilities take the necessary precaution to prevent sediment from entering their system. Current practice of the service technician does not include removal of the sediment trap for routine cleaning during appliance service. If a sediment trap has become full of debris the entire system needs attention not just the sediment trap itself. Therefore this excessive requirement serves no useful purpose for the exact location of the sediment trap. The ICC membership voted to maintain the requirement for sediment traps, but there is no need for this overly excessive requirement for the location to be after the appliance shut off valve. If a gas line “drop”, from a main line located in a ceiling space, serves two side by side (or closely located) appliances it is not uncommon to install one sedimenttrap at the bottom of the drop. The new language would require two sediment traps located after each of the appliance shut off valves. For this typical example there is a substantial increase in cost for the installation, it adds more pipe and more fittings thus creating more labor. This added cost is unjustified and simply makes no sense.

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http://www.iccsafe.org/cs/codes/documents/2006-07cycle/faa/ifgc.pdfGAMA's explaination:

"There are a variety of circumstances by which contaminants can be introduced into the house gas piping system. These circumstances range from the threading of the pipe to unexpected chemical reactions on the interior of the piping occurring sometime after the system is in use. Regardless of their origin, if contaminants do get into a gas control they can cause significant problems. As an example, if some contaminating particles are deposited on a valve seat they may prevent the valve from fully closing and a gas leak may occur."

http://www.google.com/url?sa=t&rct=j&q=gas%20appliance%20manufacturers%20assoc%20sediment%20trap&source=web&cd=1&ved=0CFoQFjAA&url=http%3A%2F%2Fwww.nachi.org%2Fforum%2Fattachments%2Ff20%2F2561d1143995655-dirt-leg-sediment-traps-gama.pdf&ei=3EP0T4mDG4TW2AW4gM30Bg&usg=AFQjCNHAMGirtzNgc0pbF_-VzVXYld311Q

Now for some news about copper and odorants:

"These contaminates accumulated on the valve seats allowing gas flow when the heater was in the off position. This resulted in gas leakage and eventual explosion. The contaminants were analyzed and found to be copper sulfide, a byproduct of the reaction between odorant in the gas and copper. It was found that a copper tube was used to connect the gas service to the water heater without using a drip leg."

http://www.croberts.com/gas-valve-failure-analysis.pdf

Learn something everyday

Francis



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[fatboy]

OK, I said I didn't have a book in front of me.......

 

[SCBO1]

I have seen galvanized pipe and soft copper used to supply water heaters in the past with direct connections to the WH.

No drip or union. Do any of you still see these hook-ups?

 

[Gregg Harris]

I have seen galvanized pipe and soft copper used to supply water heaters in the past with direct connections to the WH. No drip or union. Do any of you still see these hook-ups?

All the time and it should not be. The appliance manufacturers require it in the installation manual.

Some jurisdictions have even elected to leave out 408.4 from there code.

It is no wonder that contractors that attempt to follow the code have such a hard time in doing so when jurisdiction can not agree. If it does not necessitate a change due to a geographical constraint like temperature or chemical reaction with the earth etc. the code should be uniform to follow.