LP or Propane Gas Pressures & Natural Gas Pressure questions & answers:
Questions, answers, FAQs about the common operating pressures of natural gas and LP or liquid petroleum gas at the gas regulators, in building gas piping and at gas appliances.
This article series gives the standard pressure ranges and pressure settings for LP gas, propane gas, and natural gas fuels, including pressures found in the distribution service piping, in the in-building gas piping, and at gas fired appliances such as gas stoves, clothes dryers, furnaces, boilers, and LP gas or natural gas fired water heaters.
Since there several ways that people express gas pressures we include more than on description of common LP gas or natural gas system operating pressures in this article.
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These questions & answers about LPG or natural gas operating pressures were posted originally at GAS PRESSURES LP vs NATURAL GAS - be sure to review that article too.
On 2019-08-23 by (mod) -
Roan,
Your local building code compliance officer is the final legal authority on the safety and acceptability of your LPG or propane gas piping in your home.
It is the case that in some jurisdictions and buildings propane gas is delivered at higher pressure and reduced to the proper working pressure for gas appliances at various in-building locations. Usually this is necessary and appropriate only where there are great heights or long distances of gas piping required.
If your gas pressure drop is too much in a private residence I suspect that the gas piping is blocked, is undersized, or the first stage regulator is not properly adjusted. I'd prefer to understand why we are having a gas pressure problem before "fixing" it by just boosting pressure.
On 2019-08-23 by Roan
Can I legally run 20 psi propane.through my house - I was told it had to be low pressure - is 20 psi considered low pressure? I need more volume of gas at my generator that is on the other side of my house and I've been supplying 10" wc propane which isn't sufficient. I would like to move the second stage regulator to the generator to drop the 20 psi down to 10" wc
On 2018-04-14 by (mod) -
I would try connecting the propane tank to the regulator on the grill since you say it has been converted to LPG. Typically the regulator supplies about 11" WC and the connecting hose has a 1/4" ID such as the example I'll show below.
The unit shown can handle up to 180k BTUs - more than your grill.
The unit shown is sold by bbqguys.com the BBQ guys and also of course many other distributors.
IMAGE LOST by older version of Clark Van Oyen’s useful Comments code - now fixed. Please re-post the image if you can. Sorry. Mod.
On 2018-04-14 by Fernando Araiza
Hello,
I bought a commercial grill that has 150000 btu. It has been converted to lp. Originally it has 3/4 intake pipe for natural gas. After the conversion that pipe is connected to a regulator and ends at a 5/8 flared fitting. I know it needs 10" of pressure because it says it on the regulator. However the amount of volume I'm not sure about. I want to be able to connect it to 40 lb propane tanks without losing performance. What do I need to do?
I have attached a picture of the end fitting and of the regulator.
Thank you.
IMAGE LOST by older version of Clark Van Oyen’s useful Comments code - now fixed. Please re-post the image if you can. Sorry. Mod.
On 2018-01-12 by (mod) -
Dan,
Increasing pipe diameter for a gas or liquid can improve flow but not pressure. You would need equipment to pressurize gas into an appropriate cylinder, with the obvious safety concerns involved.
On 2018-01-11 by Anonymous
Unfortunately there is no tank or gas company to talk to... this is gas straight off of a shallow well, piped to the house. I have no way to alter a pressure regulator at the well head. I can only increase volume (through pipe size). Will increasing the pipe size reduce/ eliminate this problem?
On 2018-01-09 by (mod) -
First check the fuel level in the tank.
If there's plenty of fuel (more than 1/4 full) you might ask your service tech to check the primary regulator.
On 2018-01-09 by PD
3wall mounted propane heaters keep shutting off. Generator test run increasingly slow to pickup fuel supply and kicks all three heaters off as cold weather progresses. Bad regulator or insufficient fuel supply. Lower settting regulator at 1000 gallon buried tank, larger settting regulator at house?
On 2018-01-04 by (mod) -
Dan
It sounds as if you need a higher pressure regulator at the tank and a local step down regulator at each house. Ask your plumber or gas comany to set that up for you.
On 2018-01-04 by Dan
I have a 30k BTU ventless heater (in house B) that turns off every time the furnace in house A (upstream from the heater) comes on.
The gauge on both houses read about 8" WC when the furnace is not running, and drops to 3" of WC when the furnace kicks on. The ventless heater requires 4" WC. Will increasing the diameter of the 70' of pipe from 1" to 2" between house A and B help fix this issue?
I have about 70' of 1" DIA pipe connecting House A and B. I also have about 250' of 1" DIA pipe prior to house A that could be increased if necessary, (but this is a MUCH less desirable task).
Do you have any suggestions on how to fix this so I can run both the furnace in house A and ventless heater in house B at the same time? FYI- There is nothing I can do at a regulator to increase pressure prior to house A as it is NG from a well and I'm on the end of a 1/2 - 3/4 mile run.
(Aug 20, 2014) Nicky said:
I have a new "built-in" outside grill that I am hooking up to a 15 lb. portable propane tank (located in a separate compartment).
The manufacturer said that I need to get a high pressure regulator. The grill needs an 11" water column. What PSI would I need for that? I have found some High Pressure Stainless Braided Propane Hoses with a 30 PSI Adjustable Regulator. Should I get the 0-30 adjustable or do I only need one with a set PSI (10 PSI for instance)? Please respond ASAP.....THANKS!
[Click to enlarge any image]
Nicky,
I'm confused and surprised by the report of manufacturer's advice and suggest you go back to them to be sure we're all talking about the same product.
Usually we use a higher pressure LP gas regulator at a tank when the fuel delivery line is long and/or has to feed multiple appliances. Then each appliance has its own final gas pressure regulator to properly dispense gas at the right pressure to the burners.
For an LP gas grill whose portable propane tank is located right next to the grill itself, you'd think that the grill would have come with a single, adequate regulator to operate the appliance.
What do the installation instructions for your grille say?
(Aug 20, 2014) Nicky said:
I have a Napoleon grill Model BIM605 which can be hooked up to propane or natural gas. The propane instructions says: "Do not use hose to connect the unit. It must be connected with either rigid pipe, copper tube or an approved flexible metal connector (I will need at least a 3 foot length).
The gas supply must be connected to the 3/8" flare fitting located under the right hand side of the control panel."
It mentions using a separate line that branches off (only if using a side burner...which I'm not) It mentions the propane cylinder must be in a separate ventilated enclosure (which I have done). While trying to find the braided hose online I saw both Low & High pressure hoses, so I called Napoleon with my model #.
I was told that I would need the High pressure hose, and that the grill required 11" water column. When I asked what PSI that would be, they told me to have the Gas Company or a licensed gas fitter install it & use a manometer. This is crazy! We don't have gas on our street, and I hate to pay to have someone come just to connect 2 ends of a hose. THANKS Dan!
Reply:
Thanks for the added detail Nicky.
11 inches WC is about 0.4 psi - very low. Using high pressure hose is always safe - it's simply more durable. That's a standard LP appliance pressure and you'll see it appearing in our article GAS PRESSURES LP vs NATURAL GAS.
Nothing odd there. But you should understand that the grill company gets scared (we all do) when hearing questions from someone they don't know - they figure if you blow yourself up they don't want to be blamed.
What's critical, besides using safe plumbing as recommended by the manufacturer is having the right pressure delivered to the burners. If the grill does not contain its own pressure regulator that's why you'd need that equipment.
You can see the typical pressures at which LP gas is delivered (as a gas) to appliances as a function of temperature, in the table in the article cited.
On the portable grills I've seen the LP tank connects to a single stage regulator that is in the appliance and that regulates gas flow to the proper pressure.
(Aug 20, 2014) Nicky said:
Thank you once again Dan! I definitely feel that the Company was making sure to cover their behinds. In their instructions they kept citing installation Codes for US & Canada. US : National Fuel Gas Code, ANSI Z223.1 and using a licensed installer.
The grill does not have it's own regulator, just simply a short braided hose hooked directly into the metal tube which delivers to each burner. It's honestly not much bigger than the old grill (on wheels) that I have. This new "grill-top" unit will be set into a block wall.
Not sure if this matters but it does have a separate rotisserie that we will plug in when needed. Also in addition to gas it has an infra-red rear burner. With all that being said, I'm still a bit confused. Am I correct in assuming that I certainly don't need a 0-30 PSI regulator for this grill? If it needs 11" WC which equals 0.4 PSI then shouldn't a 10 PSI regulator should do the trick?? I can't tell you how much I've appreciated you help!
Reply:
Yes Nicky. Since your grill has NO pressure regulator and as your manufacturer cited the typical 11" (slightly less than 0.4 psi) a 0-10 psi regulator will work, but still to be safe it needs to be properly adjusted to the right delivery pressure. Unless you purchase a reg already set to the desired pressure it will need adjustment. Since installation details might affect delivery pressure that may also by the mfg says bring in someone with the right tools.
(Aug 21, 2014) Anonymous said:
Ooooohh THANK YOU Soooo Much!!! Now I can at least order the part
Reply:
Nicky
Check our article on gas appliance regulators at
inspectapedia.com/plumbing/Gas_Regulators.php
I thought about this more last night and imagined that perhaps the reasons that the grill manufacturer doesn't provide a gas regulator with their appliance might be
- with conversion parts the same appliance may work with either LP or natural gas - requiring different gas orifices at burners, different adjustments, different regulators
- the company got burned by a prior mishap and is just scared, forcing more final responsibility for safety onto the customer and their installer
(Sept 24, 2014) Anonymous said:
Why can't I use an adjustable LP gas regulator (0-20PSI) on a natural gas space heater without changing out the burner orifice ports? Seems like reducing the pressure to the heater would be enough. tomhend1@gmail.com
Anon,
The orifice size opening is equally important as is delivery pressure. Imagine a typical 5/8" diameter garden hose to which 40 psi of water is being delivered. Now reduce the hose opening diameter to 1/8" and recall from your own experience what happens to the water stream. The total flow rate in gallons per minute will be significantly reduced.
(Oct 10, 2014) scott said:
On a 100% safety valve for an LP furnace I can only adjust the water column pressure on the valve outlet to 6.25 wc
The inlet is adjusted to 12.5 wc. I checked the adjustment port spring for the outlet and it is a LP spring. I bottomed out the adjustment screw and it is still only 6.25 wc.
Is there any danger having only 6.25 wc at the outlet? The burners burn nice and I have not had any problems in the past.
Thank you
(Dec 28, 2014) James said:
I would like to connect a portable generator to natural gas. What size hose would I need to connect to it? The house is about 75 feet from where the generator will be used. Is it ok to use a hose that long? What size hose would I need? It is only a 6,000 watt generator.
(Dec 31, 2014) Anonymous said:
WHAT DOES 14" WC MEAN
fourteen inches of water column - this is one of a variety of ways to express pressure as you'll see discussed in the faqs above.
(Jan 1, 2015) scott said:
I currently am using 1/4 copper tubing for y propane log set and the flames are at a decent height, however will increasing my tubing to 3/8 produce more/higher fames?
Thank you
Scott
1/4" is pretty small - the impact, though, depends in part on the length of the tubing run and the pressure-drop at the equipment.
If you are not able to deliver gas fast enough then yes increasing the diameter would help. I would start by checkng the installation manual for the propane gas-log set to see what the manufacturer recommended in the first place.
(Jan 2, 2015) Scott said:
Thank you DanJoe
my run is about 10 to 12 feet.it is recommended @ 3/8 tubing but I do not want to remove 1/4 inch if 3/8;wont increase the flames. My reluctancy is due to having to run the tubing through my wall up 8 feet and then to the outside. If 3/8 improves the flame than it would be worth the effort
Reply:
Hey Scott
Watch out: his does not sound right. I don't know where you live, but in most countries and jurisdictions it is not permitted to route flexible copper gas tubing within building walls. Rather you must use iron piping in those locations. The concern is the possibility of puncture or other leaks in the wall cavity. And yes increasing pipe diameter will improve gas flow rate enough to be worth doing in any case.
(Jan 2, 2015) scott said:
Sounds like I should hire a plummer!?
Thank you again This is very helpful
whether i continue w flexcopper or use iron piping i intend to increase the diameter
Reply:
(Jan 2, 2015) (mod) said:
Sorry Scott, I know it's a small job - but gas piping really should be done correctly for safety reasons. Recently during a building addition we had simply to run a gas line across a 7 foot ceiling and down a 7 foot wall to a clothes dryer. That required opening the ceiling and wall enough to route black iron piping as needed; we used a sealant rated for gas piping, and after all of the lines were in place and tight we turned on the gas and tested every joint for leaks. It gave some peace of mind that was worthwhile before closing up the wall and ceiling with drywall and insulation.
In most jurisdictions you can use flexible copper for exposed gas piping but even just passing through a wall it needs to be iron pipe.
14 January 2015 Charlie said:
Hello all,
My question is specific to the height that a piped LPG gas system can extend vertically up a building before atmospheric pressure (gravity) kicks in and stops the gas flowing.
My understanding is that the regulator is normally set at 0.4psi at the storage tank. How high (within pipe work) would the gas effectively extend up a building being that LPG is denser then air, will the gas still come out of the pipe in a tall (very tall) building??
The calculations you need, using water as an example, are found at
inspectapedia.com/water/Water_Pressure_Measure.php
(Jan 16, 2015) paul said:
I have 10% left in 500gal tank and furnace quit.is lp two low 4 furnace to operate??Furnace code # 3 witch is pressure switch stuck open.
Paul,
I'm guessing you're talking about an LP gas tank since your comment is on a gas pressures information page.
Indeed in very cold weather low quantity in a tank could leave you low or out of fuel; also It's possible that the gauge is inoperative.
The meaning of "Furnace Code 3" is not something I can translate without knowing the brand and model of the heating system and its controls, but if you have the owner/installation/maintenance manual for your heater you should find the code there. If you don't have that document give us the brand, model, serial number of your heater and we'll help look for it.
(May 12, 2015) steve said:
Hi, have a question, I have a 100 gallon LP tank, I have an old Johnson model 120 furnace for blacksmithing, Jall this inside my shop, the johnson furnace has a factory requlator set up for propane, at 11 WC, which is standard. I want to run a line from my tank to the furnace set up, Reading your site, I believe I need another regulator at the tank, to reduce the tank pressure to around lets say 2 psi, to the furnace and then the furnace regulater will reduce it to 11 WC is that correct,
In other words I cant just run a line straight from the tank at tank pressure lets say 150 psi to the furnace and my furnace regulator will the adjust it to 11 wc ? If I can just use one regulator that the furnace came with, where do I find a flexible supply line to run from tank to furnace, most are made to run after it comes out of the regulator at low pressure and then connect to the appliance, please respond to my email mathrocks4@hotmail.com thanks Steve
Steve in the More Reading links at the end of this page see the
ARTICLE INDEX to GAS APPLIANCES, PIPING, CONTROLS
link and you'll find detailed articles about choosing or converting LP gas regulators, pressure requirements, 2-stage pressure regulation, etc.
Please let me know if anything you read there seems incomplete or unclear.
(June 13, 2015) Anonymous said:
What is the standard pressure for natural gas coming from the meter ?
Anon: we have added details in the article GAS PRESSURES LP vs NATURAL GAS where natural gas pressures are described.
Natural gas pressures in the building gas piping between the gas meter and the appliance regulator is typically about 7.5 to 8" wc (about 0.27-0.29 psi) and needs to be at least 0.25 psi to meet the appliance regulator's output requirements.
(July 2, 2015) Keda said:
Do you think if a product of non US origin have this statement would be okay to use in the US:
Our gas equipment for LPG is designed to fit 2.8kPa gas pressure with the connection by 9.5mm rubber hose.
Not necessarily, Keda. I would look for listing / label / approval certification by a U.S. agency such as UL. And be sure that the proper regulator is installed.
(Aug 7, 2015) Ken said:
My new apartment has an on-demand LP water heater with a typical regulator. The gas line is T'd to the patio for an LP gas grill or patio heater. Does the grill or heater require a second regulator? kmarch10@gmail.com Thanks!
Ken,
Typically each appliance has its own final stage regulator at or in the appliance itself. So there will be a first stage regulator at your LP tank and an appliance regulator at the water heater and another at the gas grille or heater.
(Aug 10, 2015) Jay said:
Thanks for all the great answers and an informative article as well. I bought a used LG LNG gas range for use at home but we only have LPG service here in the countryside. I have connected the LPG gas to it and it works alright but of course the pressure of the LPG gas coming out has made the flame too strong and unstable for cooking on.
Contacting the after-service center for LG, I was told to replace the stove because it's an old model and they do not have stock of the part (regulator) required to turn the LPG gas pressure down to usable levels for the LNG range. I'm sure it's just a matter of finding a proper regulator, no? Any ideas on what the ratio should be to turn down the LPG to? There is a regulator on the LPG tank at present.
Could it be adjusted down more or should another regulator be added to the range? Any help would be greatly appreciated. pursuntrade at gmail.com
Jay
NEVER connect the wrong type of gas supply to a gas appliance. The result is unsafe and risks fire or explosion besides the problem of improper flame and improper operation.
If you can find the gas pressure regulator specifications for the stove that you have bought it might be possible to purchase a generic gas regulator that can be set to the pressure and fuel type that your stove requires. If the stove manufacturer does not agree that such an approach is safe then you should follow their advice since the potential injury or death from a gas explosion or fire is something to take seriously.
(Aug 11, 2015) Matt said:
When sizing gas pipe using standard charts (found in National fuel gas code) and slide rules how do you know what the pressure drop is. I worked in one part of the country before (North) and am now down South. Up North we would use the chart with .5 psi pressure with a .5 in. w.c pressure drop. Never had a problem.
Down South where I am now no one seems to want to give me an answer art to the pressure drop. Figuring the pressure of the gas is not a problem it is just that pressure drop that has me stumped. Is there any simple way without extensive measurements and calculations. Thank You
[need citation from a Southern gas supplier]
(Aug 26, 2015) Anonymous said:
Seven years old plastic drain pan for A-coil in plenum of a gas furnace was deformed and caused water to drip to the furnace. When the heating system is on during winter, the heat caused the pan slowly deformed and it cannot hold anymotre water and spills water over the furnace during summer time. Is there a way to prevent the drain pan from damage?
Anon this sounds unsafe: I worry that there is heat where there should not be, or that the wrong drip pan was installed.
If there are no furnace heat leaks or other safety issues then I'd replace the plastic pan with a sheet metal one.
(Sept 9, 2015) Will said:
Have a new higher end grill. Temp cannot go below 420 F. High is about 620. So , tough to do ribs ,,etc. Old natural gas grill had a nice range of 325-525 ( lid down ).
Dedicated gas line ( same as old grill) has PSI of 2. So -- why can't this grill go lower ? BTW - hundreds of recipes call for temps at low to mid range ( 300-375 , for instance ).
Thoughts ? Advice ?
I'd like to know the brand and model and to see what the instruction book says; then we (you) could see what the manufacturer says. DO NOT modify the device: doing so is probably unsafe.
(Sept 18, 2015) judy said:
How much pressure should be in a household gas line
Please see GAS PRESSURES LP vs NATURAL GAS and let me know if questions remain.
2016/04/01 Anonymous said:
newly commissioned lpg line what is the required pressure to test the line
Anon:
Gas systems may be tested at low pressure for low pressure propane installations such as those found at a typical home using LPG. A different, high-pressure gas test procedure is also described.
NFPA 54 (2006), 8.2.3 states that "Immediately after the gas is turned on into a new system or into a system that has been initially restored after an interruption of service, the piping system shall be tested for leakage. If leakage is indicated, the gas supply shall be shut off until the necessary repairs have been made.
This test is performed with a pressure gauge installed on the "downstream" side of the final gas pressure regulator. It is testing the building's gas piping and gas appliances for leaks.
When pressure tests are performed on LPG piping, typically the system is sealed, a pressure gauge is installed, and the system is pressurized to 1 1/2 times the maximum design-operating pressure of the system OR a minimum of 3 psi. In some procedures the test period is brief: just 10 minutes for a residential building.
But the pressure test interval is increased by 1/2 hour for every 500 feet of piping (that's more likely to occur in a commercial installation).
If the pressure drops during the test period then tools or solutions are used to find the point of gas leakage. Leak testing might be by soap type solution, use of a combustible gas analyzer, or other means.
If the calculated test pressure of 1.5 x the design pressure would exceed 125 psi, then the test pressure should not exceed an amount greater than 50 percent of the pipe strength.
In a low-pressure LP gas system test, the appliance shutoff valves are "ON" (presuming that the appliances are installed) in order to assure that the appliance automatic gas shutoff features are working properly.
High pressure tests are made using a 300 psi gauge installed between the gas container (LPG) and the first stage regulator. The gas valve is opened for three seconds and then closed tightly. The system is bled down by at least 10 psi and then tested for 3 minutes, watching for a pressure drop.
A separate test can check for leaks at the gas regulator itself: a 30 psi gauge is installed at the outlet of the first stage regulator. With the pressure gauge installed, the LPG tank's gas valve is opened for 2-3 seconds, just to pressurize the regulator and test gauge. The system is bled down by at least 5 psi and observed for 3 minutes to wat ch for a pressure drop.
Watch out: these general gas leak test descriptions are for illustrative purposes and are not technically complete, detailed, nor exhaustive. Check with the gas testing specifications required where the gas installation is to be tested, and check the gas testing recommendations of the equipment manufacturers.
Watch out: WVPGA (2011) notes that the gas pressure test medium should be air or an inert gas. Never use oxygen.
2016/09/26 James w Howe Jr said:
I was taught to ALWAYS use copper flex with LP gas and black pipe with NG. I'm am NOT talking about pressure here! That stated, my supply is two 100 lb tanks with an "automatic switch over valve".
The lines from the tanks to the valve are 1/8th inch. I need to feed a 30 inch 5 burner gas stove with a convection oven, a gas clothes dryer and a tankless 10L water heater that has a 1/2 inch gas inlet. Instead of running 1/2 inch copper flex with Ts to each appliance, do i need to increase the volume in the system to have enough gas to feed all three appliances.
If I was using NG, i'd install at least a ten foot piece of 1 1/4 black pipe to build up the volume and then run 1/2 inch Ts with 1/2 inch pipe to the appliances. With LP I'd use 3/8 copper flex for the dryer and stove and the 1/2 inch called for for the water heater, BUT, I need to get enough volume first so how should I proceed?
All of the answers on your site deal with pressure and THAT is not the issue here!
Forgot my contact info: jwhowejr@centurylink.net
(mod) said:
Thanks for the comment and question, James. There's quite a list of types of piping material approved for use in gas piping systems; the distinctions I have seen are about the application - location such as above or below ground rather than the fuel difference between LP and NG.
Please see a detailed answer for your question at GAS PIPING SIZE & MATERIAL.
Watch out: Some jurisdictions such as New York City specifically prohibit use of some pipe materials such as cast iron, copper, brass, aluminum, and metallic tubing (with exceptions).
Watch out: There are life safety hazards involved when fooling with gas piping and appliances. Check with your local plumbing officials about what type of gas piping are permitted where you live, and while you’re at it, ask what gas piping or plumbing permits and safety and code compliance inspections are required where you live.
A common operating pressure for natural gas appliances is around 7 inches of water column (WC) or re-stating this in equivalent measure, that's 14.9 millibars or 1743 Pascals or Pa, or about 0.25 psi (pounds per square inch) or about 4 ounces of pressure per square inch.
See NATURAL GAS APPLIANCE PRESSURES for details.
A common operating pressure for liquid petroleum or LP gas appliance is 10" - 11" of water column (WC) or re-stating this in equivalent measures, that's 27.4 millibars or 2491 - 2739 Pascals or Pa, or about 0.36 - 0.40 psi or about 5.78 to 6.36 ounces of pressure per square inch.
See LPG & PROPANE APPLIANCE PRESSURES for details.
...
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