Increasing heat for a gas grill

[bill1]

.... It's 1.06.

View attachment 509042

I'm not seeing a hole. It sort of looks like an AN fitting for 1/8" tubing to me. But if you say it has a small hole in it, then it's probably an orifice. And 1.06 is probably the diameter in mm or .042". So a #60 drill should pass through and a #57 won't. True?

 

[pmarc]

I'm not seeing a hole. It sort of looks like an AN fitting for 1/8" tubing to me. But if you say it has a small hole in it, then it's probably an orifice. And 1.06 is probably the diameter in mm or .042". So a #60 drill should pass through and a #57 won't. True?

Well, there is a hole. But all I'm trying to do is match to the correct BTU on the chart. In order to figure if this orifice is an ng or propane item. If its ng then the legitimate ng setup was done and that's it for BTU. Without fooling around with engineering. But hey, the .042 is only on the small burner. You add the two orifices for 2 burners to get the total BTU / hr rating the product advertises. Whats the decimal value for the other orifice? I bet together they equal 21,000.

 

[bill1]

Note I was just guessing when I said those numbers might be diameters measured in mm. I'm just saying 1.06mm = .042 inches and 1.7mm = .067". You should verify if those are your two orifice diameters. From JJS' chart that would be a total of over 43000 BTU/h for propane. It is not reasonable that a small grill would have that much heat. So if your orifices are truly .042 and .067 inches, then they've been set for natural gas.

 

[pmarc]

Note I was just guessing when I said those numbers might be diameters measured in mm. I'm just saying 1.06mm = .042 inches and 1.7mm = .067". You should verify if those are your two orifice diameters. From JJS' chart that would be a total of over 43000 BTU/h for propane. It is not reasonable that a small grill would have that much heat. So if your orifices are truly .042 and .067 inches, then they've been set for natural gas.

Good analysis. I think its too coincidental not to be true - for ng. To confirm, I asked the manufacturer to mail me 2 ng orifices. Assuming I prove the ng's are installed, if I have the guts, or stupidity, I have to figure a) how much more BTU I'd like then b) bore out the orifices to the dia which matches the chart. And that's got to be a 25% BTU increase to make it worth while because the unit really sucks, now. I cant figure how anyone would market this product knowing it takes 40 minutes to cook a couple chicken breasts, including the warm-up time from a cold start. Ludicrous. Alternatively, thanx to this forum I know how to buy another grill if that's what I decide on.

 

[pmarc]

OK, pmarc, JJS gave you the keys to the kingdom so I might as well give you the shove. It sounds like your Fuego was never converted to NG, so you're going to do it.
You have to have a box of small numbered drills for both drilling and to use as gage pins. Note these small drills are brittle/fragile and vary by only thousands of an inch. If you're not used to such watchmaker tolerances like this don't try it. If you break a drill off in the orifice you have a brick for a bbq.
What size orifice do you have now? Since it's propane, the universal regulator size for propane bottles is 11"wc (water column of pressure) the orifice size will give you the BTU/h in the last column. If a #55 drill fits but a #54 doesn't, you have a 20000 BTU/h unit.
Next you HAVE to get a regulator for natural gas--you can't plumb direct to a grill. For 1/2" piping, a good size for a regulator is 3 or 4 inch-wc.
Many are sold for both LP & NG applications. That's impossible. That means you have to disassemble it and (usually just) reverse a part so the regulator spring is less compressed for the lower pressure NG application.
Let's say you have purchased, and verified the spring setting, for 4"wc. From the table (for our example case of starting with 20000BTU/h propane) you will need to enlarge the orifice to a #44 hole to get 20000btu/h for 4"wc Nat Gas. Of course you would start several sizes smaller and work your way up.
Don't take shortcuts and make sure you understand what you're doing. Good luck.

Do you see a regulator in this NG conversion kit. It's what we bought and installed.

 

[Fueling Around]

bill1 found your problem, the regulator.
Your "kit" didn't include a regulator for the LPG to NG conversion.
You will need to purchase a NG low pressure regulator.
Actually, I would complain to the manufacturer their kit is incomplete for the conversion. $50 is pretty pricey for the few pieces provided.

...
Next you HAVE to get a regulator for natural gas--you can't plumb direct to a grill. For 1/2" piping, a good size for a regulator is 3 or 4 inch-wc.
Many are sold for both LP & NG applications. That's impossible. That means you have to disassemble it and (usually just) reverse a part so the regulator spring is less compressed for the lower pressure NG application.
...

Good catch Bill.
All regulators I've seen on consumer appliances are NOT alterable by the end user. I'm sure that is a liability issue.

 

[pmarc]

bill1 found your problem, the regulator.
Your "kit" didn't include a regulator for the LPG to NG conversion.
You will need to purchase a NG low pressure regulator.
Actually, I would complain to the manufacturer their kit is incomplete for the conversion. $50 is pretty pricey for the few pieces provided.
Good catch Bill.
All regulators I've seen on consumer appliances are NOT alterable by the end user. I'm sure that is a liability issue.

Do you think the ng setup, without the ng regulator, negatively affects the heat output? Not to suggest I'd continue without the regulator. But I'm just trying to isolate the current extreme low heat issue.

 

[forktender]

Weber

Weber won't even sell you parts to convert a grill from LP to NG or the other way around, anymore. Gone are the days of swapping out orifices to convert a grill over to NG or LP gas.
They will only sell you part for your specific grill, people are way too prone to lawsuits these days, so they have to cover their ass just to be safe. The first thing I would try is a regulator for a grill that has more burners, I found this out by mistake, when I thought I bought the right regulator, the grill worked way better with the wrong replacement regulator.

 

[pmarc]

Weber won't even sell you parts to convert a grill from LP to NG or the other way around, anymore. Gone are the days of swapping out orifices to convert a grill over to NG or LP gas.
They will only sell you part for your specific grill, people are way too prone to lawsuits these days, so they have to cover their ass just to be safe. The first thing I would try is a regulator for a grill that has more burners, I found this out by mistake, when I thought I bought the right regulator, the grill worked way better with the wrong replacement regulator.

After reading, yesterday, it seems buying an ng regulator assumes the pressure in the incoming line varies. Maybe it was a moment of low pressure that I saw the most extreme slowness in cooking. But logic tells me there's nothing imminently dangerous about going without the ng regulator. And yes, it did surprise me that a company would let the consumer install an ng kit himself. And yes I agree with someone earlier $50 is a heck of a lot to pay for an ng conversion kit. Having been in manufacturing I'll tell you its their chance to make a few dollars to make up for losing a few dollars somewhere else.

 

[pmarc]

After reading, yesterday, it seems buying an ng regulator assumes the pressure in the incoming line varies. Maybe it was a moment of low pressure that I saw the most extreme slowness in cooking. But logic tells me there's nothing imminently dangerous about going without the ng regulator. And yes, it did surprise me that a company would let the consumer install an ng kit himself. And yes I agree with someone earlier $50 is a heck of a lot to pay for an ng conversion kit. Having been in manufacturing I'll tell you its their chance to make a few dollars to make up for losing a few dollars somewhere else.

Actually, I see far less risk in this. If I begin by turning the gas knob to 1 (it has 10 notches), after orifices are bored out.

 

[SecondHandSmoker]

But logic tells me there's nothing imminently dangerous about going without the ng regulator.

That is correct if the NG line supplying the grill is regulated upstream.
Is the NG line supplying the grill already regulated upstream?
Be mindful that if the upstream regulator ever fails, and they do fail, then there is nothing stepping the pressure back down to the correct WC displacment for your specific grill before the gas enters the grill.
This creates a dangerous situation with the grill.
That is why it is always a good idea to install an appliance regulator as a safety net.

 

[pmarc]

That is correct if the NG line supplying the grill is regulated upstream.
Is the NG line supplying the grill already regulated upstream?
Be mindful that if the upstream regulator ever fails, and they do fail, then there is nothing stepping the pressure back down to the correct WC displacment for your specific grill before the gas enters the grill.
This creates a dangerous situation with the grill.
That is why it is always a good idea to install an appliance regulator as a safety net.

Good point. At the front of the house... you can see the the gas meter, on right. And the unit hanging off the left of it looks like a regulator. The same shape an an LP reg but much bigger for the entire house - guessing.

 

[SecondHandSmoker]

Good point. At the front of the house... you can see the the gas meter, on right. And the unit hanging off the left of it looks like a regulator. The same shape an an LP reg but much bigger for the entire house - guessing.

Yes, that is the main regulator on the main gas supply line for the house. Usually the regulator is set at 0.25 psi or 6.9" WC. So, if your NG gas grill calls for 7" WC, you're in the ballpark.
Still a secondary regulator at the grill is a good idea, though.

 

[bill1]

Yes, every gas service entrance has to have a regulator. That is what you identified just to the left of the service meter. They're typically adjusted to anywhere from 5 to 22 inchesWC. UBC also calls for a separate regulator for outside appliances, probably due to the fact they tend to be somewhat portable and with flexible fittings. The other benefit of having a dedicated regulator at your grill is you'll know what the supplied pressure is so you can size your orifices correctly. If you don't have one at your grill (and they're only $20!!!) you must measure the pressure there, in inches of water column, to know what size orifices to use. You can't just assume the service entrance regulator is set at a reasonable value for your orifices!

You seem resistant to gauging (measuring) the orifices you have...do you not have a box of numbered drills? That's kind of basic. Are you sure you're up to doing this sort of work? There are a lot of common household items (paperclips, mechanical pencil leads, etc) that can be trusted as quite accurate gauges of small holes. Do you need some advice there?

Finally I sure hope that plumbing on the left in your last picture is water. (That regulator is intended only for water.) If it's not , that is a very unsafe contraption for gas.

Finally, many low heat problems with grills is just due to spider cobwebs in the plumbing line...particularly at the orifices. Have you disassembled what you have (with any gas valved off) to assume that's not your problem.?

 

[forktender]

Yes, every gas service entrance has to have a regulator. That is what you identified just to the left of the service meter. They're typically adjusted to anywhere from 5 to 22 inchesWC. UBC also calls for a separate regulator for outside appliances, probably due to the fact they tend to be somewhat portable and with flexible fittings. The other benefit of having a dedicated regulator at your grill is you'll know what the supplied pressure is so you can size your orifices correctly. If you don't have one at your grill (and they're only $20!!!) you must measure the pressure there, in inches of water column, to know what size orifices to use. You can't just assume the service entrance regulator is set at a reasonable value for your orifices!

You seem resistant to gauging (measuring) the orifices you have...do you not have a box of numbered drills? That's kind of basic. Are you sure you're up to doing this sort of work? There are a lot of common household items (paperclips, mechanical pencil leads, etc) that can be trusted as quite accurate gauges of small holes. Do you need some advice there?

Finally I sure hope that plumbing on the left in your last picture is water. (That regulator is intended only for water.) If it's not , that is a very unsafe contraption for gas.

Finally, many low heat problems with grills is just due to spider cobwebs in the plumbing line...particularly at the orifices. Have you disassembled what you have (with any gas valved off) to assume that's not your problem.?

The plumbing on the left is most definitely water piping, seeing that it is soldered copper pipe.
As far as I know is soldered copper pipe hasn't been acceptable for LP or NG in well over 40 years according to the UPC Universal Plumbing Code written by IAPMO for the entire USA.

 

[pmarc]

The plumbing on the left is most definitely water piping, seeing that it is soldered copper pipe.
As far as I know is soldered copper pipe hasn't been acceptable for LP or NG in well over 40 years according to the UPC Universal Plumbing Code written by IAPMO for the entire USA.

Fuego Grills just confirmed the numbers I see on orifices are for their ng ones (they're metric, as the grill is made in China). And yes I can confirm the hole diameters even further using drill bits, as I own many. I'm not going to worry about copper piping or a possible broken house regulator, for now. I only need 60 minutes to test once the orifices are drilled out. So... using the BTU chart as my guide what next step do you suggest in order to make new holes which won't blow up the house? (incidentally, Fuego said the house regulator suffices and thats why they dont supply one. I didn't attempt to correct them.) But I did complain about the lousy heat.

 

[pmarc]

Yes, every gas service entrance has to have a regulator. That is what you identified just to the left of the service meter. They're typically adjusted to anywhere from 5 to 22 inchesWC. UBC also calls for a separate regulator for outside appliances, probably due to the fact they tend to be somewhat portable and with flexible fittings. The other benefit of having a dedicated regulator at your grill is you'll know what the supplied pressure is so you can size your orifices correctly. If you don't have one at your grill (and they're only $20!!!) you must measure the pressure there, in inches of water column, to know what size orifices to use. You can't just assume the service entrance regulator is set at a reasonable value for your orifices!

You seem resistant to gauging (measuring) the orifices you have...do you not have a box of numbered drills? That's kind of basic. Are you sure you're up to doing this sort of work? There are a lot of common household items (paperclips, mechanical pencil leads, etc) that can be trusted as quite accurate gauges of small holes. Do you need some advice there?

Finally I sure hope that plumbing on the left in your last picture is water. (That regulator is intended only for water.) If it's not , that is a very unsafe contraption for gas.

Finally, many low heat problems with grills is just due to spider cobwebs in the plumbing line...particularly at the orifices. Have you disassembled what you have (with any gas valved off) to assume that's not your problem.?

No spider webs or other impediments. But Fuego said my line should be at 7" WC to work right. If I were to increase pressure then my kitchen gas stove wouldn't work right.

 

[pmarc]

No spider webs or other impediments. But Fuego said my line should be at 7" WC to work right. If I were to increase pressure then my kitchen gas stove wouldn't work right.

Can someone run numbers on the resulting ng flow from a 1.5” pipe reduced to a 1” pipe?

 

[bill1]

For the flow associated with a 20kBTU/h grill, the pressure drop from 1.5 to 1.0 pipe is negligible. (Unless that 1" line is >100' or something typically non-residential.)

You seem to be saying Fuego provided you NG orifices and they require supplied 7"wc pressure. But you have no idea what your gas pressure is at the grill nor how big the orifices really are. Could someone have opened them up without your knowledge? Did you buy the grill used? I suspect your pressure may be too low at your grill. That can be solved with a 3 or 4 inch-wc regulator and then opening up the orifices appropriately to their designed BTU/h values. But if you don't have access to numbered drills so you can MEASURE, how could you possibly open them up?

 

[pmarc]

For the flow associated with a 20kBTU/h grill, the pressure drop from 1.5 to 1.0 pipe is negligible. (Unless that 1" line is >100' or something typically non-residential.)

You seem to be saying Fuego provided you NG orifices and they require supplied 7"wc pressure. But you have no idea what your gas pressure is at the grill nor how big the orifices really are. Could someone have opened them up without your knowledge? Did you buy the grill used? I suspect your pressure may be too low at your grill. That can be solved with a 3 or 4 inch-wc regulator and then opening up the orifices appropriately to their designed BTU/h values. But if you don't have access to numbered drills so you can MEASURE, how could you possibly open them up?

1. Thanx for the flow info.
2. Yes 7"wc pressure.
3. Bought the grill new.
4. I have an enormous set of drills. My earlier confirmation on this got lost in the sauce.
5. I will now measure the orifices and match the btu/hr in the chart.
6. BTW the manufacturer recently gave me numbers on their orifices designating ng. They match on mine. Nevertheless, I'll measure them.
7. QUESTION: if the orifices already match the advertised btu/hr ... whats the sense in opening them up, which would be dangerous, correct? I mean I'd have no bearing or basis for selecting the new hole sizes. Unless maybe if I open them up incrementally and test them on low.
8. The 1" pipe runs 100 feet to the grill.