NG supply - does this look right?


 
Steve-G

Steve-G

TVWBB Fan
I just wanted to bounce this off of this knowledgeable group. I'm working on swapping out grills in a stone enclosure, and I took a closer look at the natural gas pipes leading to the grill manifold. At first it didn't look right because the pipes went from 1/2" to 1/4" to a 3/8" regulator to 1/4" to the manifold. In my mind, it didn't make sense that they would have downsized the pipe to 1/4" before upsizing to a 3/8" regulator. But after doing some reading, it seems like it should be fine. I think I have a water pipe mentality where downsizing will increase pressure and reduce flow, and vice versa for upsizing. But gas is a different animal.

It was probably installed by a professional plumber because of all of the work done on the enclosure and they had to run another NG line outside, so I'm assuming it is okay. What do you think?

1/2" pipe leading into the enclosure:
1683552924715.png

1/2" pipe on left coming into the enclosure. Then 1/4" bendable pipe in question to 3/8" inlet/outlet regulator to 1/4" pipe to grill manifold on the right.
1683553107876.png

I need to replace the bendable pipe before the regulator for this project anyway, and I'm planning to just replace it with a 1/4" pipe like it is right now. I was originally thinking of using a 3/8" corrugated gas connection line like this, but now I'm not sure (ignore the fittings - I was just using this as an example):

1683553510876.png
 
“Does it look right” is open ended.

What are you seeking to do here?

The plumbing appears to be professionally installed sans there’s no paint on the iron pipe to protect it against corrosion.

If you’re asking, “will this installation run deliver enough gas to my new bbq?” Then more data and info is needed.

What is the currently installed pipe run length? What are the new grill’s fuel source requirements?
 
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I can only speak for my geographic area, but we don’t see a second stage regulator used in residential natural gas applications. The utility typically provides somewhere around 7” of water column in incoming pressure to the whole home. I’d want more information before trying to pass any sort of judgement.
 
It all looks fine until you see what is "inside". Not sure about running 1/4" flex copper. I recall back in the early 60s when post mounted "Warm Morning" grills were all the rage, I saw lots of them installed by the builders with 1/4" flex copper. Not sure your installation will support a new modern grill especially one that sucks down a lot of BTU.
I would get rid of everything past the 1/2" gas line. BTW that 1/2" will supply far more gas than you might imagine. Should be sufficient for anything but the largest most BTU hungry thing you can get. Hell, I have 1/2" and it can run 2 grills flat out with no loss of heat output. (My retired Genesis and my Wolf). The Genesis is only a 36k BTU max grill but the Wolf is a beast. Yet both (when needed) run just fine even at full tilt.
Would also help to know what you're expecting to run on this getup as well
 
Guys - thanks for the feedback. Sorry, I probably left out some important details so I'll try to clarify.

Since the new grill will actually be less BTU's than the one I'm ripping out, I'm going to make the assumption that everything leading up to that 1/2" shutoff valve should be more than adequate. I'm also making the assumption that I'm at 7" WC at that point (or maybe slightly less due to normal pressure drop throughout the system) assuming everything is sized properly.

The old grill had two main burners rated at 15K BTU each and 1 rotisserie burner at 12.5K BTU, so a total rating of 42,500 BTU. The replacement grill will have two main burners at 18.5K BTU each and nothing else, so a total rating of 37,000 BTU. The installation instructions for both specify that the operating pressure for this grill should be 3" WC, which is why I'm assuming that extra regulator is installed. I will be verifying the pressure after that regulator later this week to make sure it is 3" WC, so right now I'm just assuming. I will be checking the pressure to make sure that the regulator is still working properly.

As far as Brett's question about the pipe length, it is 3/4" pipe up until the last 15' before that shutoff valve, so plenty big enough to handle the 37,000 BTU (if I'm reading the charts correctly).

I hope this helps. I guess the main question I've got is whether you've ever seen anything like this where the pipe diameter decreases, then increases, and then decreases again before getting to the appliance/grill. It just didn't look right to me, but it's also something I've never had to deal with before.
 
The pressure will be the same throughout the system up to the regulator. The size of the piping will only change the potential "volume" of gas.. Think of it like your house wiring. Some is 14ga some 12ga and some maybe even 10ga. All carry the same "pressure" (volts). But, the volume (amps) is where the different gauge wiring will vary. So honestly it really does not matter if prior to the 3"WC regulator what the pressure is as long as it's more than 3"WC. Since the regulator is there to maintain 3" for the grill being used. Hope I explained that well. So really Steve, I would only be concerned about the corrosion that seems to be there between the copper and black pipe. There does not seem to be dielectric coupler there. So that concerns me more than whether or not there will be enough gas for your needs
 
Steve-G said:
I hope this helps. I guess the main question I've got is whether you've ever seen anything like this where the pipe diameter decreases, then increases, and then decreases again before getting to the appliance/grill. It just didn't look right to me, but it's also something I've never had to deal with before.
Click to expand...

I have seen some bizarre gas plumbing hacks, yet they have all been LPG.
the NG hose for my E330 NG which has 48000 BTU plus a 10,000 or 12,000 BTU side burner is 3/8, so I think 3/8 is sufficient for your grill.

The reason I suggested measuring WC above is so you can determine if you need that regulator that's in place or not.

I would look at the inches of WC needed for the grill you are installing, and if it matches the pressure needed without the regulator, don't use it.

btw, this is the hose my E330 uses

Weber Grill Parts: 10 Foot Long 1/2" ID Natural Gas Hose WITH 3/8" QUICK DISCONNECT FITTING | grillparts.com | BBQ Repair and Replacement Parts

Weber BBQ parts: 10 Foot Long 1/2" ID Natural Gas Hose WITH 3/8" QUICK DISCONNECT FITTING
www.grillparts.com www.grillparts.com
 
If he's not having issues elsewhere on the line I would think it should be fine. I just don't like that corrosion. Far more concerned about the dissimilar metals being in direct contact than the pressure
 
Steve-G said:
As far as Brett's question about the pipe length, it is 3/4" pipe up until the last 15' before that shutoff valve, so plenty big enough to handle the 37,000 BTU (if I'm reading the charts correctly).
Click to expand...
you need to know total run length from home stub to connection to grill. it sounds like you're NOT at 100' or so but more like 15-20' total run length. if so, and with your stated BTUs to be burned, 1/2" diameter pipe at 15-20' should not present a gas supply issue at 7WC.

i would recco no regulator in-line until the grill's regulator. so you're a full pipe run up to the grill's regulator. i do not know your codes so take this all with a grain of salt. i have never seen two regulator in-line for any grill setup, my all my NG experiences are with modern homes (25 years or newer in age.

DO, HOWEVER, abrade your black pipe that's above ground and paint it so as to stop the pipe from rusting.

I would be CONCERNED if you have black pipe below grade and in contact with the earth and that pipe is old, as in 60 years or so. Buried black pipe in earth, unsheathed or unprotected, will rot and weaken over a long time. a modern below grade (buried in dirt/sand) install uses a polyethylene pipe and a similar riser to get above grade. then above grade pipes can be black pipe and painted. just check the condition of your below grade pipes.

again, i do not know your local codes. check with an expert or learn the codes yourself.

and from Dan's pic highlighted above, that's a very hard 90 degree bend in a pipe. gas should flow in arcs, not hard 90's so i'd start at your rigid pipe and build-new-to-the-grill from that point.

and the fewer interconnections you have, the fewer possible leak points you have too.
 
Brett-EDH said:
you need to know total run length from home stub to connection to grill. it sounds like you're NOT at 100' or so but more like 15-20' total run length. if so, and with your stated BTUs to be burned, 1/2" diameter pipe at 15-20' should not present a gas supply issue at 7WC.

i would recco no regulator in-line until the grill's regulator. so you're a full pipe run up to the grill's regulator. i do not know your codes so take this all with a grain of salt. i have never seen two regulator in-line for any grill setup, my all my NG experiences are with modern homes (25 years or newer in age.

DO, HOWEVER, abrade your black pipe that's above ground and paint it so as to stop the pipe from rusting.

I would be CONCERNED if you have black pipe below grade and in contact with the earth and that pipe is old, as in 60 years or so. Buried black pipe in earth, unsheathed or unprotected, will rot and weaken over a long time. a modern below grade (buried in dirt/sand) install uses a polyethylene pipe and a similar riser to get above grade. then above grade pipes can be black pipe and painted. just check the condition of your below grade pipes.

again, i do not know your local codes. check with an expert or learn the codes yourself.

and from Dan's pic highlighted above, that's a very hard 90 degree bend in a pipe. gas should flow in arcs, not hard 90's so i'd start at your rigid pipe and build-new-to-the-grill from that point.

and the fewer interconnections you have, the fewer possible leak points you have too.
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Brett - you bring up some good questions/points.

Correct, I'm not concerned about a gas supply issue with the combination of my run length, pipe size, and BTU rating of the grill.

The grill itself does not have a regulator, so if I remove it I'll probably be closer to 7" WC (I can check what Dan suggested earlier to see what is coming in). There is a 1/4" hard pipe going from the regulator directly into the manifold. It is a Ducane, and I think someone else on this forum mentioned that they were sold by HVAC and LP companies, so maybe they figured that if you were buying an NG version, someone was coming out to your place to install it and add the appropriate regulator.
1683574812287.png

It seems like I should be concerned about the rust that is happening, so I will deal with that. And this week I will see what is going on with that buried black pipe. It is in a shallow rock bed, about an inch above ground level and under 3"-4" of stones. I never thought about that being a concern. Based on the age of the grill, it has been sitting in that rock bed for about 25 years.

When you mentioned the "hard 90 degree bend", did you mean the 90 adapter coming off the black pipe, or that bend in the copper tube that looks a little kinked? If you are talking about the tube, then I'm in complete agreement with you. I didn't like how that looked, and then when I started disassembling the grill, I made one of the kinks even worse. That is part of the reason I started this thread. The pipe after the regulator looks like a good setup since the 1/4" pipe came with the grill. But that section between the black pipe and the regulator is what I think can be improved. It could be just a matter of what was available 25 years ago when this was installed, but now I can possibly make a better, simplified connection.
 
LMichaels said:
The pressure will be the same throughout the system up to the regulator. The size of the piping will only change the potential "volume" of gas.. Think of it like your house wiring. Some is 14ga some 12ga and some maybe even 10ga. All carry the same "pressure" (volts). But, the volume (amps) is where the different gauge wiring will vary. So honestly it really does not matter if prior to the 3"WC regulator what the pressure is as long as it's more than 3"WC. Since the regulator is there to maintain 3" for the grill being used. Hope I explained that well. So really Steve, I would only be concerned about the corrosion that seems to be there between the copper and black pipe. There does not seem to be dielectric coupler there. So that concerns me more than whether or not there will be enough gas for your needs
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Thanks for adding the point about a dielectic union. That makes perfect sense and is probably what is happening with the corrosion at that point. I'll keep that in mind as fix that connection.
 
Steve-G said:
It was probably installed by a professional plumber because of all of the work done on the enclosure and they had to run another NG line outside, so I'm assuming it is okay. What do you think?
Click to expand...
If it has a shutoff right inside the wall or basement then that's how the pros do a stub out.
You want that extra shutoff inline if you ever have to service the outside shutoff, instead of shutting off the main.
 
Steve-G said:
Makes sense to find out the NG pressure at this point. I'm hoping it is in the 6.5"-7" WC range, otherwise I probably have a bigger issue going on. Thanks.
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As I said earlier. As long as it's over the rating of the regulator it doesn't matter if you have 4" or 10". Worry more about the volume not the pressure. The regulator is there to handle regulating pressure for you. Then worry about the corroded fittings. Get rid of the copper to iron connections. I am assuming that like my own line, it's stubbed out of an extension from say your other gas appliance(s) in the house. Water heater, clothes dryer, stove, etc. If the other appliances on the ine are running ok then your grill line is ok. I think you got too much worrying about something that you shouldn't worry about. IIRC you're installing another old Ducane grill in that cook island. If so even with that little copper line you have plenty of volume. Also because I owned a Ducane NG grill I can tell you from just looking that you have the same regulator that was in the base of the Ducane I had. Also FWIW BroilMaster included the same regulator. Because I also had a BM NG grill with that same regulator in it. Just get rid of the copper line directly connected to black iron, hook up the grill and cook.
 
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