Any ideas about propane pressures?

[rtimgray]

I'm working on an addition to our house, and within this addition we plan to have two addtional sets of gas logs. One of them is a set that we have had for several years and replaced with a nicer looking mantel and set of logs. The other we haven't purchased yet, but it will be a very small unit for a room that is about 350 sq ft.

Anyway, the questions is this: we currently have a 500 gallon tank setting about 30 ft from the house, connected to the house via a 1/2" copper line that goes from the tank to a regulator mounted on the house. From the regulator, I have 3/4" black iron pipe that runs inside and has a 1/2" branch to our oven and a 1/2" to one set of logs. Total length of pipe run is about 40'. In the addition, I'll have about the same length of piping run, the same way - a 3/4" line that splits to two 1/2" branches near the end. I will be connecting this outside.

Will I need to run another 1/2" line from thank to the house and have two regulators, or will I be able to tie into the existing line "downstream" of the existing regulator? I have no idea what the pressure coming out of the regulator is now, but I'm pretty sure it's less than a pound (FWIW, I've pressure tested all of the new black iron pipe I've run to 100 PSI for 48 hours and have not had any leaks, so I think I'm good as far as that's concerned).

Anybody have experience with propane pressure regulators and how much is required to feed the load as listed above?

Thanks.

 

[oldnslo]

Are you on speaking terms with your propane supplier? If yes I would ask them since their may be different flow rate models of regulators depending on the area being used.

For reference: I have three regulators running off of a 1/2" copper main line. Two of them are running 60,000 BTU furnaces in different parts of my home and the 3rd feeds my 17kw generator.

 

[farmer2009]

I had some regulators humming when the heaters were on. Come to find out from my lp guy they were at the limit. Seems they are rated for btu's. They were 1.5 million btu regulators and I was pulling 1.35 million thru them. The propane supplier upgraded them to a 3 million unit no more humming and am getting better heating out of them. So check with your supplier. Mine were no cost because they own to the meters. He didn't upgrade lines or anything just changed regulators at tank. Now I also have a secondary regulator at each heater.

 

[rtimgray]

Thanks for the responses. I was thinking that might be the case - either an exchange of regulators or adjustment of the existing one. When I get ready to do the tie in, I'll get in touch with one of them.

Thanks again.

 

[bandaidmd]

I think your gas supplier will recommend a second supply line for that extra 40' of pipe in the addition. LP gas pressure is measured in water column and is set @ about 9" i'm not sure what that works out to in psi.


edit ,I googled this for you.

Propane Regulators - LP Gas Pressure Regulation

"Regulator Purpose
Propane tank pressure can range from under 10 psig to over 200 psig. Residential applications will generally require 11 inches water column (amount of pressure required to push a column of water up 11 inches in a manometer, or about 6.3 ounces per square inch) and the regulator compensates for these pressure differences in the tank to supply a steady flow of required pressure to the household appliances. Not all applications are similar to that of residential use and will therefore utilize regulators for higher and lower pressures as required by the appliance(s). In summary, the purpose of a propane regulator is to "bottleneck" the propane down to a safe and usable pressure. An important point to note is that under normal operation, a propane regulator will make a "humming" noise. This is normal and should not be construed as a problem or regulator malfunction."

 

[forgeblast]

I would ask the propane supplier to hook it up. We did when we put in our lp stove, and they were very reasonable and very professional.

 

[Gary Fowler]

You don't want to increase the pressure, just the flow. A larger flowing regulator may be required, talk to your LP gas supplier and they can advise you if your current regulator needs upgrading. There is no need to put downstream regulators in place at the heater if you have the correct tank regulator.

 

[ray66v]

You don't want to increase the pressure, just the flow. A larger flowing regulator may be required, talk to your LP gas supplier and they can advise you if your current regulator needs upgrading.

Exactly right.

The amount of pressure that exists inside the building is very low. Once you get past the last regulator, it's all about the volume.

Commonly a 1" line or larger, is used to feed smaller branches inside a residences.

If the line is not large enough to supply the required volume to the appliances, the pressure will drop.

 

[farmer2009]

In summary, the purpose of a propane regulator is to "bottleneck" the propane down to a safe and usable pressure. An important point to note is that under normal operation, a propane regulator will make a "humming" noise. This is normal and should not be construed as a problem or regulator malfunction."

Some "humming" is normal but you shouldn't be able to hear it 500' away inside a residence over the tv with water running in the kitchen.

 

[nc redneck]

Consider a 1/2 lb or 2 lb system. It is used a lot a lot in commercial jobs. In my case it reduced the 3 inch welded pipe ( big bucks ) down to 1 1/2 black pipe. Saved me about 10 grand on this job. Supplying (2) 1.5 million btu air make up units for collision repair center.
hope this helps.