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SamGupta · Jun 2, 2008, 10:01 AM

Hi,
I am trying to finish my basement and have a gas pipe running right through the center of a room. I was planning on moving it out of the way into the soffits forming a tray ceiling. Is there a requirement that the gas pipe always has to slope upwards? If so what should the slope be? Can there be a bend in the gas pipe that goes down and then upwards. This is for natural gas.

Thanks
Sam.

ballengerb1 · Jun 2, 2008, 11:05 AM

Sam, slope required for drain pipes only not gas pipe.

speedball1 · Jun 2, 2008, 11:07 AM

We don't run many gas lines in my area but when we do we always slope the back to the meter. The reason being is that there's a drip loop installed to catch any moisture in the line before it snuffs out your pilot lite. Sloping the supply line back to the drip loop makes sure that any moisture will drain back to the drip loop and not in the heater. Did this answer your question. Regards, Tom

ballengerb1 · Jun 2, 2008, 12:39 PM

We do have traps up North but there's usually one right at the meter and then again at each appliance. I use so much CSST up and over beams and ducts that I do not worry about slope at all.

truck 41 · Jun 2, 2008, 05:03 PM

Sam, in the southwest we don't worry about slope on gas lines, but we do install driplegs on the end of each run just before tieing in each gas appliance,its basically a tee with a six inch nipple and cap at the bottom to catch any moisture before the flex to the appliance.
Check your local plumbing code. Good luck.------Zeke

speedball1 · Jun 3, 2008, 05:15 AM

Truck,
If you placed the drip leg next to the meter instead of next to the appliance and sloped the gas line back to it if the dripleg filled up you would have the entire run of the gas line to build up moisture before it got to the pilot light. Your way would knock out the pilot as soon as the drip leg filled up. I like our way better. Regards, Tom

truck 41 · Jun 3, 2008, 09:34 PM

Originally Posted by speedball1

Truck,
If you placed the drip leg next tothe meter instead of next to the appliance and sloped the gas line back to it if the dripleg filled up you would have the entire run of the gas line to build up moisture before it got to the pilot light. Your way would knock out the pilot as soon as the drip leg filled up. I like our way better. regards, Tom

Understood thanks tom----zeke

NaturalGasMan · Jul 6, 2008, 11:35 AM

Working for a gas utility in the NW I am wondering where you guys are having so much trouble with mositure in your lines? Our system has spent many dollars installing dryers and filters in the mains. In the NW you do not need to install your piping in any slope, just look at your meter, the gas enters the top, down into the meter and back out the top. If you are getting any moisture through your meter into your house then I would contact your supplier. There is more of a problem then what sloping your pipes is going to fix. And as stated above CSST is pretty much the norm for piping of gas and it runs up, down, sideways etc...

Milo Dolezal · Jul 6, 2008, 11:58 AM

You guys answered Sam's question many times over. I just want to add my two cents: I have heard about possibility of moisture problem in gas systems - but in 35 years around plumbing - I have never encountered one. All our gas projects are inspected by City Inspectors and we have never had this issue to come up.

Sam, don't worry about any slope in gas pipe. Re-route your pipe as you need.

iamgrowler · Jul 6, 2008, 06:21 PM

Originally Posted by Milo Dolezal

You guys answered Sam's question many times over. I just want to add my two cents: I have heard about possibility of moisture problem in gas systems - but in 35 years around plumbing - I have never encountered one. All our gas projects are inspected by City Inspectors and we have never had this issue to come up.

Sam, don't worry about any slope in gas pipe. Re-route your pipe as you need.

NG on the West Coast is typically piped straight from the North Slope.

In other parts of the country (Midwest, inland New England and Appalachia in particular), NG is cracked from coal or shale.

The cracking process generally leaves a great deal of moisture in the final product.

Milo Dolezal · Jul 6, 2008, 06:24 PM

iamgrowler: That's a great info ! Thanks !

NaturalGasMan · Jul 6, 2008, 11:51 PM

I would just like to clarify that I have never heard of any one even attempting to slope a gas line, for one it is a pressurized system, there is always verticalness and horizontals in a gas line. Finally if you did slope it and there was any sort of water build up what so ever it would block the flow of gas until the pressure pushed its way past the blockage. This can be seen in burners that pulse, if there was a significant amount of water it would get caught in the bellows of the meter, if it made it through the meter and into your house line there would be a substantial amount of water, this could not even be considered moisture. It would ruin the valves in your equipment and your utility would be liable for the repair of your equipment.
I work on gas equipment every day for the past 10 years and in the NW have never found water in a drip leg. Occasionally some compressor oil if Williams Energy messes up.

massplumber2008 · Jul 7, 2008, 04:46 AM

Hello all:

NGman...

I've been sloping natural gas pipes all my life. The Massachusetts Uniform State Plumbing Code (93) requires that all gas pipes be sloped at 1/4" per 15 feet of gas piping and for good reason, too!

In fact, I have seen condensate in the drip legs at many gas appliances over the years... I am not saying I see it every day, but under certain conditions I have been able to remove the drip leg and let water drip out from the cap.

Iamgrowler explained the reason quite well... NG comes from coal or shale in our area and the process retains moisture.

Anyway... that's how it goes around here. There are no absolutes in plumbing or gas piping. Each state has its own code requirement and that is what Sam gupta needs to be advised on here...

Sam... check with your local plumbing and/or gas inspector in your area as you may in fact be required to pitch your gas pipes.

And Bob... you should also double check about sloping CSST in your area as well... may be that you should be sloping your pipes as well... ;) Let me know will you..?

Good day all...

MARK

speedball1 · Jul 7, 2008, 05:06 AM

I would just like to clarify that I have never heard of any one even attempting to slope a gas line, for one it is a pressurized system, there is always verticalness and horizontals in a gas line. Finally if you did slope it and there was any sort of water build up what so ever it would block the flow of gas until the pressure pushed its way past the blockage. .

Gee Gassy, Makes you kind of wonder why, if as you say, "I work on gas equipment every day for the past 10 years and in the NW have never found water in a drip leg." you install drip legs on your lines at all. As I've stated, in my area we don't use much gas but back in Wisconsin, 50 years ago, we ran out gas lines out of black iron and sloped back to a drip leg. Growler saved the day with his explanation. Thanks Steve! Tom,

KISS · Jul 7, 2008, 07:34 AM

I've been following this thread and what's interesting, is that it makes me go back to an old axiom: Determine which world you are in before making assumptions.

This translates loosely in this case where the AHJ has the final jusisdiction.

But some examples close to home:

With up/down toggle switches, up is always on. Nope, some one threw in an n-way switch.

Electric power door locks use nown for lock, probably because of the original mechanical locks.

Given colors of red and yellow, what color is positive. In thermocouples, RED is positive.

Given black and white, what color is negative. In household wireing white is usually neutral.

Given red and black which wire is negative? In a car black is usually negative.

What would you use to connect a 7/8 OD copper tube?
A 3/4 fitting or a 7/8 fitting? If you went in a refrigeration shop you'd ask for a 7/8. Plumping shop 3/4.

Is a 2 x 4 2" x 4", no, that's the nominal dimensions. I seem to remember 1-3/4 x 3- 3/4?

Did you ever learn that resistivity can be written as ohms/square? How many squares of shingles do I need for my roof? Are they the same? Nope.

Power generated is negative. Do we have -5 Megawatt Plants? No.

Solar cells have short circuit current. It's negative. Is it portrayed as negative, No.

I need 6 yds of cement. The matematician says, that's a linear measure. The concrete company gives you 6 cubic yards without complaining.

Word of warning...

ASSUME - makes an A$$-(out of)U-ME.

This was a unique discussion. The picky said Natural Gas. The informed may have said natural gas found in this part of the US or Natural gas having these percentages of impurities.

I can go one a little different. What power does your desktop computer run on. You might say 85-285 VAC 50/50 Hz.

You can ask the power company what power they supply and they will say 120 V/ 60 Cps. Nope. That's the nominal value. What about balckouts, brownouts, frequency differences (50.9-60.1 or whatever it is), lightning strikes etc.

Your computer gets hit by lightning, the manufacturer washes his hands because you did not supply power in the range specified.

You can design somethng to work on 12 VDC and put it in the car and it will die. Whay -200 V and +50 V transients are present in the electrical system. Accessories go off when you start the car. When operating the accessory without the car on, voltage drops with time.

If it was an antique car it could be negative ground or positive ground or 6 volt.

Know where you are and know the customs of where your going.

NaturalGasMan · Jul 7, 2008, 12:00 PM

I apologize if I have offend anyone, all that I have been going off for the water content in the system is the federal standards set for pipeline distribution. Here is a link to verify if you would like, although it is off the subject of pipe slope. NaturalGas.org
As far as why we still install "Drip Legs" In our part of the world they are called "Sediment traps" They catch lots of nasty chips that flow through the pipes of homes with Black Iron or galvanized etc... as well as the compressor oil that I mentioned earlier.
Natural gas is attained in different ways but still has to meet certain criteria to be able to be put in to the Pipeline system. Again I can only go off Federal Regulations, I guess maybe some states are skirting them in some manner.
And I agree to save yourself the biggest headaches you should follow all laws and local code requirements no matter how antiquated they are. Some like spitting on the City street in Portland Ore, can get you a day in the stockade. But still on the books...
Tony

KISS · Jul 7, 2008, 12:08 PM

Those sediment traps, a.k.a dirt legs, only are required on the lowest gas appliances, thus a stove on the ground floor doesn't need one, but the heater in the basement does. As for water, they work for that too.

Water vapour just doesn't combust.

Water laying in a pipe can cause corrosion of iron and I guess where this is severe, sloping is required.