NG pressure / flow question

Reply

  #1  
Old 04-30-15, 12:35 PM
O
Member
Thread Starter
Join Date: Mar 2014
Posts: 19
Received 0 Votes on 0 Posts
NG pressure / flow question

I had a 1/2" line split from my main supply in the garage that runs into my indoor fireplace (which is rarely used). I plan on heating my garage this winter, so I tee'd off a stick to that, as well as ran a 20' length to the opening of my garage doors so that it could feed my burner that I use to make beer.

It's a pretty large burner, rated with propane and a 30psi reg. up to 200k btu.
Amazon.com : Bayou Classic BG14 Banjo Burner 10 inch diameter : Grill Parts : Patio, Lawn & Garden

That being said, I was using just that setup before I ran these pipes, and it would heat my 26 gallon kettle to a rolling boil pretty easily.

I bought this to convert the burner to NG, but do not have a regulator (which I was under the impression that you didn't need, although in the directions it says something about a reg):
HURRICANE NATURAL GAS CONVERSION VALVE | William's Brewing

So from my T, I have 20' of 1/2, with about another 5' going vertical so that my shutoff and quick disconnect would be chest height for easy access. I also have a 10' 3/8" hose so that I can get the burner out onto the concrete apron. This all being said, on my test run last night, it barely got 5 gallons to a boil, and it was a pretty weak boil at that.

Where do I start. I would imagine it just doesn't have the flowrate to support such a large demand. Would taking off the 5' vertical stick and 10' of the original 20' help at all or is flow rate constant through the entire pipe?

Thanks and let me know if you need clarification.
 
  #2  
Old 04-30-15, 01:32 PM
P
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 24,424
Received 747 Votes on 686 Posts
Natural gas in your home is at about .25 psi (yes, a quarter of one psi) and propane contains more btu's than natural gas so sticking with natural gas is an uphill battle. The only way that burner gets that many btu's is by burning propane at 30 psi. You won't be able to get anywhere near 200k btu running that burner on natural gas and especially at the low household pressure. I think you need to seriously consider running the brew burner off a tank of propane.

If you really want to plumb your brew rig into natural gas I think you need to contact the gas company and see what your options are for having a second, higher pressure regulator installed. I assume that cost will be prohibitive and make propane tanks seem like a no-brainer.

Forget orifice changes or anything like that. You could run a straight 1/2" pipe into that burner and it's won't produce 200k btu/hr. With 50' of 1/2" pipe between your meter/regulator and your brew rig you can only get about about 46'000 btu of gas to flow through a pipe that size. You're bumping into the physics of a very low pressure gas in a small pipe.

---
My last brew was a Doppelbock and I'm running a modified burner off propane at 2 psi.
 
  #3  
Old 04-30-15, 02:30 PM
lawrosa's Avatar
Super Moderator
Join Date: Dec 2010
Location: Galivants Ferry SC USA
Posts: 18,152
Received 62 Votes on 54 Posts
The pipe size for natural gas is probably too small to supply the 200K burner... Basically your starving for gas...

You need to do a pipe calc of the home and we need to know all pipe sizes and lengths of pipe. All appliances on those lines and BTU ratings of each..

As Dane said if all are undersized then you need to increase pipe size in areas or have the PSI jacked up.. There could be more variables but this is just a start.
 
  #4  
Old 05-01-15, 06:56 AM
O
Member
Thread Starter
Join Date: Mar 2014
Posts: 19
Received 0 Votes on 0 Posts
Good deal. I called and talked to the gas company last night and am going to see about having a higher pressure reg installed. They said it should be free, so if that's the case I'm going to have them up it for "future improvements". Appreciate the help, I'll keep you posted.
 
  #5  
Old 05-01-15, 08:25 AM
P
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 24,424
Received 747 Votes on 686 Posts
Bayou likely won't help you if you call for advice, probably for liability reasons, so you may be on your own for dialing it in. You may have to re-jet the burner depending on the gas pressure you get. You can search out a good service provider for gas devices, probably someone that services agricultural or industrial gas devices. My local propane company has a service dept that takes care of the many tobacco curing barns and they were very helpful. Not only did they have a huge stock of hoses, fitting, regulators & jets but I told them what I was doing and they pretty quickly pointed me in the right direction for what was needed. Just by experience they knew about what size orifice what would be required and it saved a lot of guessing and fine tuning.

For safety you don't want to leave the flexible gas hose pressurized when not in use in case it gets damaged somehow so a shutoff valve before the hose is a good idea. It also serves as a safety in case there is a fire on the brew rig and you can't get to the valves on the rig you can kill gas to the whole system from a safe distance.
 
  #6  
Old 05-01-15, 10:20 AM
O
Member
Thread Starter
Join Date: Mar 2014
Posts: 19
Received 0 Votes on 0 Posts
For sure. I have the QD on the black pipe, with a shutoff. It always gets shut off, and hose disconnected and wrapped up. By no means a permanent thing. Appreciate the warning though.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: