NG supply - does this look right?


 
LMichaels said:
For something hidden in a cabinet. Heck I think I even have an extra one here he can have.
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yeah but who knows what his old one's condition is. i don't care about the shiny new parts, it's more about functioning safety. but what do i know. i'm a coal burner.
 
Brett-EDH said:
yeah but who knows what his old one's condition is. i don't care about the shiny new parts, it's more about functioning safety. but what do i know. i'm a coal burner.
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No matter. Honestly those things just flat don't break or wear out. Since they are always having gas in them (unlike one on an LP grill) which are disconnected often, left open to atmosphere and such. These are not. They just sit there and do their job. Plus they're not subjected to the high pressures of an LP tank. They rarely even see above 8" WC. It's why they can be buried in a cabinet or an appliance and simply forgotten about. But, I think I have a basically brand new one. If he wants it.
 
I was able to grab some fittings, a connector hose, and a manometer from Menards and pieced things together in order to get some readings. Please ignore the mish-mash of fittings for now. I will make sure I get the proper ones when I do the final install.

Natural gas pressure from the supply is 8" WC:
1683721325194.png

Pressure after the regulator is 6.5" WC, definitely not the specified 3" WC from the Ducane installation guide:
1683721926618.png

The other thing I discovered is that a 1/4" connection hose isn't even readily available anymore, even if I wanted to keep the same setup as before. Not that I was planning to - just an observation. I bought a 1/2" connection hose that had a fitting for my 1/2" black pipe, so that part was easy. Now I just have to see if I can adjust the spring in the regulator to get me down to 3" WC, otherwise I need to get a new regulator.
 
Steve-G said:
I was able to grab some fittings, a connector hose, and a manometer from Menards and pieced things together in order to get some readings. Please ignore the mish-mash of fittings for now. I will make sure I get the proper ones when I do the final install.

Natural gas pressure from the supply is 8" WC:
View attachment 70397

Pressure after the regulator is 6.5" WC, definitely not the specified 3" WC from the Ducane installation guide:
View attachment 70398

The other thing I discovered is that a 1/4" connection hose isn't even readily available anymore, even if I wanted to keep the same setup as before. Not that I was planning to - just an observation. I bought a 1/2" connection hose that had a fitting for my 1/2" black pipe, so that part was easy. Now I just have to see if I can adjust the spring in the regulator to get me down to 3" WC, otherwise I need to get a new regulator.
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Looks like someone may have messed with the regulator. But don't throw the baby out with the bathwater. You need to test it with "flow" IOW "working pressure". If you're familiar with using an air compressor you will know what I mean. Ex, most of my air tools require 90 PSI. However if you allow air flow the pressure will drop WAY below 90 PSI. So you are possibly seeing the same thing here. Hook it up to a grill and test it with the grill "running". You should then see 3 to 4" WC When turned off you will see the pressure jump back up
 
LMichaels said:
Looks like someone may have messed with the regulator. But don't throw the baby out with the bathwater. You need to test it with "flow" IOW "working pressure". If you're familiar with using an air compressor you will know what I mean. Ex, most of my air tools require 90 PSI. However if you allow air flow the pressure will drop WAY below 90 PSI. So you are possibly seeing the same thing here. Hook it up to a grill and test it with the grill "running". You should then see 3 to 4" WC When turned off you will see the pressure jump back up
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I think I understand what you are saying and that makes sense, but I'm not sure how to test for that. The gauges on an air compressor are inline and allow air through the system as it is measuring. The way I have it set up, I'm basically blocking the outlet with the gauge.

Since neither the regulator nor the grill manifold has a test port or side tap, I could insert a T-fitting into the line after the regulator, put the manometer onto that T, and hook up the rest of the system and turn it on. But I'm trying to figure out if that is correct or not. How much of a pressure drop should I expect with just two small orifices going into the burners? I'm assuming not very much at all.
 
Yes that's how I test them. But, all things considered I don't think I would sweat what you're seeing. If you feel more comfortable replacing it I recommend these https://www.amazon.com/dp/B0923G3XR9/?tag=tvwb-20 I actually have an extra one. Only reason I took it off the line was when I set my Genesis up I sized my orifices for 7"WC or basic line pressure. I don't have a lot of "loads" on my gas line so really did not need the regulator for making things more even. But honestly I would not give it a second thought what you're seeing as it's entirely normal.
 
I've got an update on this. I did some different connections and figured out a way to measuring the working or operating pressure by simulating the grill running. Larry, I didn't realize it would drop that much, but you were totally right. With a little adjustment to the regulator, I'm at a 3" WC operating pressure.

So now the question becomes, how do you measure the true "operating pressure"? Is it when both burners are on high? Because having them both on high is quite a bit different than if I have only one burner on or both of them on medium or low. Which makes a lot of sense. I have them both on high and set the regulator to 3", but when I close one valve it jumps up to 4.5" WC.

I'm assuming I set it at 3" with both burners on high unless someone tells me differently.

Here are the installation directions from Ducane:
1683056471373-png.70046
 
I always looked at it more as an "average" type thing.. IOW not at max flow but more of a mid range flow. I could be wrong on it, it's just one of my theories LOL. And quite honestly I never worried about things too much. IOW if I verified I had full pressure 6.5 to 7.5" or so and I had a regulator I knew no one messed with. I just went with it and didn't worry about it. Assuming also I knew I had sufficiently sized pipe for good flow
 
I wanted to update this thread one more time in case someone runs across it and wants to know if it was resolved. A neighbor had a digital manometer that I was able to borrow, and the regulator that I found had a side tap on it for testing pressure while the grill was operating.

Pressure while grill was off = 7" WC
1684699813128.png

Operating pressure with one burner on high & one burner off = 4.1" WC
Operating pressure with both burners on high = 3.8" WC
Operating pressure with both burners on medium = 4.1" WC
Operating pressure with both burners on low = 4.2" WC

So Larry, going back to your thought on setting it at mid range flow instead of max flow, it looks like it would not swing the measurement too much using one method or the other. I might set the regulator so that it is at 3" when both burners are on high (worse case scenario), and I should still be less than 3.5" if its on medium or low, so definitely in the same ballpark. And yes, I totally realize I'm overthinking all of this, but once I went down the rabbit hole, I had a hard time coming back out.

I may have to tweak it a little bit after I increase my orifice size ever so slightly based on the chart (new burners are 18,500 BTU vs the old ones which were 15,000 BTU each), but I'm getting really close to the 3" WC operating pressure that Ducane recommends. It is bright sunlight today so I'm having a hard time seeing the flame size and quality, so I need to look again tonight. But it looks like the burners that I got with the donor grill are in worse shape than I was expecting, so I might need to make a small investment.

The other good thing that I was able to test is that my system was holding a constant pressure after I shut off the gas supply. When I had checked it last week with some different fittings and the old manifold, it was dropping slowly when I shut off the valve behind the grill, so there must have been a small leak somewhere.
 
Honestly all I really have ever done is if I intend to use a regulator, I buy one. They're usually rated at 3 or 4 WC. Honestly it won't matter a hill of beans either way. So I simply assume the device is correct and only assure I have sufficient operating pressure at the unregulated supply outlet. I've never worried about it much after that. Or I test what I have and if I or the person I did them for did not want to use a regulator, if I found between 6 to 8 inches I would simply size the orifices accordingly. I never saw a need to get any more granular than that.
 
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