Natural Gas line question - help with sizing for grill

[GirchyGirchy]

Everyone,

I was hoping for some help. I've ordered a Weber Genesis 330 NG and at some point will need to get the plumbing ready for it. I have a path pretty well picked out but am concerned about the sizing. The grill puts out a max of 60k BTU, or 55 cubic ft/hr. The line I'm hoping to use it an existing supply for a ventless fireplace and is 1/2" line.

The existing line is about 17' long and ends in a reducer from a 3/4" supply. I'd like to just keep the existing part and, to make it to the grill, would end up adding an additional 30' of 1/2" line. Using some websites for calculations, adding in equivalencies for the tee and elbows it ends up at ~63' of line. The grill itself has a 10' flex hose for its supply, so now I'm up to 73'.

A couple of charts I've found list the max capacity of a 1/2" line at 70' to be 61 ft^3/hr and 80' is 57 ft^3/hr. This is getting pretty close to the max 55 that the grill can put out. I've also found other charts which list much lower numbers (in the high 30s).

Personally, I'd rather just expand on what I have for a few reasons - it's cheaper (thinner line, plus not replacing exsiting piping/fittings), I don't end up wasting the line that's already there, and it's just less work. But I don't want to end up wishing I'd gone with the larger pipe because I run into a lack of available gas when running all main burners, the sear burner, and the side burner all on high. Granted, it's likely not going to be often I do that, but the possibility exists.

Right now I'm leaning towards starting over and running a 3/4" line, but just wanted some input. Any help would be appreciated!

Brian

 

[pop pop]

Never doubt good calculations.

 

[gmwelder86]

I just ran a 1" line for a guy for an outdoor fireplace, you would be amazing the kind of BTU draw something have. I can check my codebook later as far as distance/BTUH draw for sizing. Whats the BTU rate on your BBQ and how far are you going. We dont normally do fitting/legnth equivalent unless its for a steam line.

 

[GirchyGirchy]

Whats the BTU rate on your BBQ and how far are you going. We dont normally do fitting/legnth equivalent unless its for a steam line.

60k BTU, 47' line + 10' flex for the grill.

 

[Ricoch3T]

60k BTU, 47' line + 10' flex for the grill.

Nice... I just bought a 330 myself although I have propane instead of NG.

So your 1/2" line feeds only the fireplace right now correct? Do you have a BTU rating on that?

What kind of pipe is it and what do you plan to run?

 

[Ricoch3T]

well heres what I'm looking at in the code book...

I assume you don't have 2psi input.

at 80 ft you have 56 (61600 btu) cubic feet per hour with 1/2" metallic pipe
70ft you get 60 cubic feet (66000 btu)

you would be close JUST figuring in the btu for the grill.

3/4 @ 80 foot on the other hand would put you at 177 cu ft or 128700 btu's
metallic pipe only.. if you use wardflex or something else it'll be a little different

 

[GirchyGirchy]

Nice... I just bought a 330 myself although I have propane instead of NG.

So your 1/2" line feeds only the fireplace right now correct? Do you have a BTU rating on that?

What kind of pipe is it and what do you plan to run?

Do you like yours so far? I can't wait to try it out. Originally I was thinking of a Spirit, then wanted a side burner, then said screw it and went for the Genesis. I'm getting it about half price after some gift cards and a coupon. The sad old Sunbeam I bought for $3 (and sadly only recently had to re-replace the burners due to a raccoon and refill the propane tank) is being donated to my neighbor.

Yes, that's all the line is for. I wasn't even fooling with the fireplace since it's only been used a few times since we've lived there (I hate ventless). Even if I felt like grilling out in the cold and the fireplace was on, I'd just shut it off.

It's all black pipe and that's what I'm going to run.

 

[therealjakeg]

You'll be fine thats all I do all day long.. check the signature. You will not even notice the difference on 7" water colum. (1/4 POUND SYSTEM) Again youre good to go buddy. FYI there is an abundance of natural gas now in the United States and it is cheaper than two years ago by half. Please use as much as you can. .

Your local NG rep.

 

[fishheds]

If you've got 3/4" black iron or galvanized to the fireplace,you should be able to carry the grill run with 3/4" CSST.Gastite and Tracpipe are the two major brands.It's not approved for underground and it's a little pricey,but super easy to run.
Or,if you're set up on a 2# system,you could use 1/2",probably even 3/8" (OD)copper and mount a 2# to 7" (maxitrol 325 series)regulator just upstream of your flex connector.
It's been a few years,so the way copper prices are going,the price difference may be negligile.

 

[RECox286]

Around here most NG grills are hooked to the house side of the meter piping

with a saddle valve and anywhere from 3/8 to 5/8 soft copper. Given that,

I should think, not being an engineer, that you would be OK with the 1/2" as

long as you are either using the grill, or the fireplace, but not both at the same

time.

Uncle Bob

 

[mrobins297aaa]

Something you need to consider is how far you are from the gas meter, if you are on a low pressure system it makes a big differences on how you size the pipe.
This is the chart we used in the detroit area to size residential gas pipe.

how to read this chart, you take the distance from the meter to the farthest appliance.
lets say your bbq is the farthest and lets say its 100'.........you use the column at 100' feet to size all the loads, so say the total building load is 300k btu's you would use 1 1/4 pipe for the main then all the branches are sized according to the capacity of the size of the pipe in that column.......1/2" could handle 38k btu's, 3/4" could handle 79k btu's

you can see that if the farthest appliance is only 30' away it makes a big difference on the capacity of the pipe size.

that chart is right out of the bocca book.

 

[GirchyGirchy]

I need to double check what pressure I'm at right now - is that normally visible on the meter, or will I need to call the gas company?

 

[GirchyGirchy]

Something you need to consider is how far you are from the gas meter, if you are on a low pressure system it makes a big differences on how you size the pipe.
This is the chart we used in the detroit area to size residential gas pipe.

That's similar to one chart I saw....the others had much higher values. Odd.

 

[Notch1988]

I just ran a BBQ gas line in 1/2" and after buying our new Napoleon BBQ I had to swedge down to 3/8" for the quick connects that came with it.

 

[mrobins297aaa]

That's similar to one chart I saw....the others had much higher values. Odd.

could have something to do with the specific gravity of the gas .6 was the figure consumers power used for there gas in the detroit area they also rated there gas at 1000 btu's per cubic feet. I can't remember the exact details but if its different it changes the values on that chart.
give your gas supplier a call

 

[brewchief]

could have something to do with the specific gravity of the gas .6 was the figure consumers power used for there gas in the detroit area they also rated there gas at 1000 btu's per cubic feet. I can't remember the exact details but if its different it changes the values on that chart.
give your gas supplier a call

That chart only allows for .3" water column, other charts may allow a greater drop, a chart that allows for 1" water column drop will show a higher capacity.

 

[Ricoch3T]

Do you like yours so far? I can't wait to try it out. Originally I was thinking of a Spirit, then wanted a side burner, then said screw it and went for the Genesis. I'm getting it about half price after some gift cards and a coupon. The sad old Sunbeam I bought for $3 (and sadly only recently had to re-replace the burners due to a raccoon and refill the propane tank) is being donated to my neighbor.

Yes, that's all the line is for. I wasn't even fooling with the fireplace since it's only been used a few times since we've lived there (I hate ventless). Even if I felt like grilling out in the cold and the fireplace was on, I'd just shut it off.

It's all black pipe and that's what I'm going to run.

I've only used it a couple times but so far so good. It's been a while since I've grilled so I'm still getting used to it.
I waited a couple years trying to get a sale or something on it but never could. I ended up saving the 5pct from my lowes card

 

[mrobins297aaa]

That chart only allows for .3" water column, other charts may allow a greater drop, a chart that allows for 1" water column drop will show a higher capacity.

makes sense

 

[GirchyGirchy]

I've only used it a couple times but so far so good. It's been a while since I've grilled so I'm still getting used to it.
I waited a couple years trying to get a sale or something on it but never could. I ended up saving the 5pct from my lowes card

Yeah, never seen them on sale either. I put mine together this weekend, can't wait to use it!

I think I'm going to go ahead and do most of the run in 3/4", then reduce to 1/2" just before going outside. This way I can reuse some of the existing pipe and make a smaller hole through the house, plus it would need to reduce down to 1/2" at some point for the quick disconnect anyway.

I was hoping to use MB Sturgis's BBQ Box (small enclosure with built-in ball valve and quick disconnect, looks pretty nice) but it's only in 3/8". I think I'll find some sort of exterior plumbing or electrical box to use instead.