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Photograph of residential LP or liquid petroleum gas tanks outdoorsPropane - LP Gas Tank Installation, Location, Piping, Filling, & Inspection

LP or Propane Gas Tank Installation, inspection, controls, repairs:

Here we provide descriptions and photographs of unsafe gas piping, indications of unsafe or improperly operating gas appliances, gas meters, and other gas installation defects are provided. The photo above shows two 24-gallon LP gas tanks installed outdoors on a wobbly unstable base.

This document also provides free sample draft home inspection report language for reporting defects in oil and gas piping at residential properties. Do not copy contents from InspectApedia to other websites.

InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.

LP Gas Tank Observations & Gas Tank Safety Recommendations for Home Inspectors & Home Owners

LP Gas tank above groundGeneral safety warning: improper installation and even improper inspection and testing methods involving natural or "LP" gas can involve dangerous conditions and risk fire or explosion.

Watch Out: If you smell gas you should leave the building immediately > and should do so without doing anything that could create a spark such as operating a light switch or telephone.

Watch Out: From a safe location, call your gas company's emergency line and/or your fire department.

Article Series Contents

Watch out: Immediate LP or natural gas safety hazards: if there is evidence of an LP or natural gas leak at a building, gas odors, for example, you should:

Photograph of bottled gas regulator connections

LP gas tanks [liquid petroleum gas tanks] are normally placed only outdoors, above ground or (if the tank is designed for it), buried below ground.

Where LP tank regulators can be exposed to the weather, especially in northern climates exposed to freezing weather, they should be protected from water and frost to prevent potentially dangerous damage to the LP gas pressure regulator, shown as the gray disk behind the right-most tank in this photograph of LP gas tanks in the Hudson Valley of New York.

LP gas tank regulators are discussed

at GAS REGULATORS for LP TANKS

How Does the LP Gas Company Fill the LP Gas Tank at a Building?

LP gas tank being filled by Bottini Fuel, Poughkeepsie NY (C) Daniel Friedman at left our LP gas tank is being filled by an automatic delivery schedule. Photo courtesy of the author & Bottini Fuels, Poughkeepsie, NY.[9]

There are several ways your LP gas company will know when to make a delivery.

If your building uses piped-in natural gas, fuel delivery is continuous through the piping system and of course you won't have an LP gas tank at your property.

Watch out: if you have run out of LP gas entirely your fuel delivery driver may refuse to re-fill the tank unless provision can be made to assure that pilot lights in the building are also re-lit and that the building is safe from risk of a gas leak.

LP gas tank being filled by Bottini Fuel, Poughkeepsie NY (C) Daniel Friedman

The fuel delivery driver will (or should) refuse to deliver LP gas if he is aware of unsafe conditions such as a leak or nearby open flames.

And since the LP gas delivery truck driver has to pull a heavy gas hose and nozzle from the truck to your LP tank, you don't want to run out of fuel in the dead of winter with deep snow-cover and no path cleared to the LP gas tank.

LP gas delivery meter on the fuel truck (C) Daniel Friedman 2013

The LP gas delivery driver will print a receipt that documents the date, time, and quantity of LP fuel delivered to the building.

To protect customers from a dishonest LP gas delivery driver, the fuel meter will not print a receipt if the LP gas delivery truck has moved at all from the time of start of LP gas pumping.

Our driver explained that otherwise, "in the old days" of older LP gas meters, a dishonest driver could drop off LP gas at multiple properties, billing just the last customer for fuel.

Is the LP Gas Tank Supposed to be Filled to the Very Top of the Tank or to 100% on the Gas Gauge?

No.

LP Gas tank fill-volume is typically to 80-85% of capacity, leaving vapor space in the tank.

The LP gas company does not fill the tank to its very top as that would not leave sufficient room for expansion of the liquid fuel as temperatures increase from the temperature of the liquid propane at the time of delivery.

This is an important safety detail: your gas company is not short-changing you.
NOTES: Liquid propane has a comparatively high coefficient of expansion (> 50 psig per °F - O'Brien (2010)

REALLY? NIST in discussing the coefficienty of expansion of propane cites that for propane, at temperatures from about 85K to 650K the pressure will range from 1kPa to 4521 kPa as a function of temperature and pressure.

The same source offers this additional data: Density (Liquid) as a function of Temperature and Pressure Temperature from 85.525 K to 369.89 K
Pressure from 1 kPa to 1000000 kPa - NIST (2014))

Overpressure in the LP tank can cause direct venting of combustible gas to the atmosphere, liquid fuel in the distribution lines, abnormally high and thus unsafe pressures at the appliance, or even a ruptured tank. . - Ramirez et als. (retrieved 2014)

Details are at GAS PRESSURES LP vs NATURAL GAS

How & Where to Install Above Ground Liquid Petroleum Gas Tanks - LP or Bottled Gas Tanks: Clearance Distances

Specifications for Installing & Inspecting Above-ground LP Gas Storage Tanks - gas cylinders not filled on site

These LP Gas tank location clearances for above-ground LP gas tanks are given as measured from the tank's relief valve in any direction away from any potential source of ignition (of a gas leak) or where leaking gas could be drawn into a building window or other vent opening.

If your fuel is piped-in natural gas rather than from an onsite storage tank of LP gas, you will want to

see GAS METER CODES & CLEARANCE DISTANCES.

Sample gas tank inspection report language: Safety: Install secure and level support for the LP gas tank at ... -

if a tank tips over and breaks gas line it could be dangerous. This is an inexpensive item. This item should be handled promptly on establishing gas service for the house, preferably before tanks are filled.

Also see BURIED LP GAS TANK INSTALLATION SPECIFICATIONS

Specifications for Installing & Inspecting Above-ground LP Gas Storage Tanks - gas cylinders that are to be filled on site: Clearance Distances

Below is a common LP gas tank cleareance distance skectch example used by most authoirities, cited from NFPA 58 in its Appendix I.

[Click to enlarge any image]

Above ground LP gas tank clearance distance specifications - example: check with your local LP gas company and building department for safe clearances for your installation.

Reader Question: proper backfill for a buried propane tank

(Sept 15, 2014) Hal said:
I am confused as to the proper backfill for a 1000 gallon propane tank, one supplier uses sand, another limestone. which one is recommended?

Reply:

Hal

The concern with *any* backfill on tanks or piping is to avoid sharp rocks or objects that, through settlement, might perforate or damage the equipment. I'm not sure what sort of limestone nor what size gravel that contractor uses, but sand sounds safer to me.

See the following references for code and specificastions for installing underground propane or LPG Tanks

LPG Propane Tank Codes & Regulations

Access cover for buried LP gas tank

Installation Specifications for Below-ground LP Gas Storage Tank: Clearance Distances

Ten-Foot Clearance Rules for Underground LPG Storage Tanks

We provide additional ABOVE GROUND LP GAS TANK INSTALLATION SPECIFICATIONS and for gas tanks or gas cylinders.

Specifications for Finding, Inspecting, Installing Buried LP Gas Tanks

Photograph of the fill valve and regulator and tank gauge for a buried LP Gas tank

How to Find a Buried LP Gas Tank

Finding a buried LP gas tank should not be difficult at a property, since the top of the tank has to be accessible for filling and inspection.

Look for the access cover, usually white steel on older LP gas cylinders or black plastic covering an access well on new buried LP gas tanks, as we mention next.

At some new properties you may first have to see and recognize the plastic access well and cover such as the buried LP gas tank cover shown in these photographs.

When the buried LP gas tank access cover is opened, the buried LP gas tank fill valve and regulator are plainly visible as should be a gauge indicating the remaining amount of LP gas in the tank.

How to Find & Read the LP Gas Tank Gauge Guide

LP Gas tank gaugeThe LP tank gauge is installed at a fitting either on the tank top itself or on a combination fitting at the tank top where the gas valves and connections are also installed.

This Liquid Petroleum Gas Tank Gauge - LP tank gauge or bottled gas tank gauge shows us that it is intended for installation on a 200 Lb. LP gas cylinder, and that the tank is at about 40% full.

LP Gas tanks are normally filled before the tank is totally empty. The liquid petroleum gas delivery truck driver can assure that no contaminants have leaked into the tank if it is still under pressure.

LP tanks are usually not filled to 100% of tank capacity, since doing so would risk sending liquefied LP gas out of the gas tank and into the regulator where it could cause damage or be unsafe.

The curved graph at the upper end of the LP gas gauge dial shows the effects of temperature on the LP gas stored in the tank and thus on the effective remaining amount of fuel in the tank.

Some smaller LP gas cylinders may lack a gauge. When a gas cylinder has no percentage-full gauge and we want to know if the tank is empty or nearly so, we gently rock the tank (be careful not to cause a gas leak).

If the tank is heavy and hard to move it's probably nearly full.

A bit of experience with pushing slightly on the tank just before and just after it has been filled by your LP gas delivery company can make it easy to have a general idea of the level of fuel in the tank.

Be sure that LP gas cylinders are not so loose or poorly supported that they can tip over - risking injury or even a gas leak and explosion!

LP Gas Tank Data Tag & Age Information

Data tag on a 1997 LP tank in Two Harbors MN (C) Daniel Friedman at InspectApedia.com

Our photis shows the data tag for a residential propane tank installed in Two Harbors, Minnesota. You can, with a bit of careful wiping-off of dirt and dust, note that this tank was made in 1997.

... 1997 LP tank in Two Harbors MN (C) Daniel Friedman at InspectApedia.com

[Click to enlarge any image]

Our service technician said that the oldest tank he's encountered in the area was from the 1940s and that they do not have a program that requires replacing LP gas tanks based on age - a requirement that you may encounter in some jurisdictions.

Propane tank old enough that the gas company would not re-fill it - it was replaced (C) Daniel Friedman at InspectApedia.com

Above and below: this LP gas tank installed in a home in San Miguel de Allende, Mexico, in 1992, was replaced in 2017 by the gas supplier. The company was no longer willing to re-fill the old tank, as their drivers considered it unsafe.

Propane tank old enough that the gas company would not re-fill it - it was replaced (C) Daniel Friedman at InspectApedia.com

The new, replacement lP tank is shown below as it was being filled for the first time.

New LP tank being filled for the first time (C) Daniel Friedman at InspectApedia.com

LP Gas Tank Home Safety Tips & Inspection Report Language Examples

Here are some LP gas safety recommendations and home inspection report examples:

LP Gas Cylinder that is Incompletely Buried

Propane Gas Tank Safety Recommendations: The liquid propane gas tank at ... is partially buried

- this may not be a recommended building practice; accelerated rust may lead to failure of the container. Please review this question with the gas supply company.

Propane Gas Tank Safety Recommendations:

Be sure that the safety relief valve and controls atop the LP gas tanks outside are protected from icing (for example from exposure to rain or gutter overflow). Iced controls can prevent proper operation of safety devices.

 




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Reader Comments, Questions & Answers About The Article Above

Below you will find questions and answers previously posted on this page at its page bottom reader comment box.

Reader Q&A - also see RECOMMENDED ARTICLES & FAQs

On 2021-10-20 by inspectapedia.com.moderator (mod) - clearance distance is given for LP or propane tanks.

@Fritz F,

Please look in the article above on this page where you will see several clearance distance is given for LP or propane tanks. Do let us know if any of that is unclear.

Above on this page where it says:

“These LP Gas tank location clearances for above-ground LP gas tanks are given as measured from the tank's relief valve in any direction away from any potential source of ignition (of a gas leak) or where leaking gas could be drawn into a building window or other vent opening.”

And then review the NFPA diagram above on this page for the distances shown for the different items you ask about as this is used by most authorities.

Keep in mind, of course, that federal, state, and local ordinances must be followed at all times. You can always check with your local building authority if you aren’t confident in the propane companies’ answers.

On 2021-10-20 by Fritz F

What is the proper spacing distance of a horizontal 250 gallon above-ground LP tank from a house wall, windows, heat pump and fixed generator? Are the spacing distances measured from the fill valve, the pressure relief valve, or any closest part of the tank?

I’ve gotten two different answers from two different propane companies, and I’m not sure that either one is according to code or the standard NFPA spacing diagram. Thanks.

On 2021-04-01 by (mod)

@John,

Thank you for continuing to press for usable detail on exact clearance distances for LP regulators and other LP components.

In the article above, at the section titled

Specifications for Installing & Inspecting Above-ground LP Gas Storage Tanks - gas cylinders that are to be filled on site: Clearance Distances

you will see an illustration that you can click-on to see an enlarged, detailed version from which I excerpt below.

You'll see that the "code" illustrators draw clearance distance lines from the point of concern to the closest point of the cover over the LP tank gas valve and regulator assembly.

Most-often that's take as from the closest point on the cover over the LP tank gas valve and regulator assembly to the closest point on the item in question - window, electrical panel, etc. So you'd measure from closest point on the cover if the regulator is under the cover, or on the vent if you're permitted to relocate it, to the closest point on the exterior of the electrical box.

But watch out: in some installations the regulator is not under that cover but instead is nearby, attached to the building wall.

Rather than get into an argument with a building inspector, IMO it makes sense from a safety view as well as a cost and time view, to locate LP tanks and regulators far enough away from points of concern that there is no ambiguity.

In your specific case you're going need to ask if moving the regulator-vent outlet using sufficiently sized- and properly-located- pipe will satisfy the local code inspector who's the final authority.

On 2021-04-01 by (mod)

@John,

Thank you for continuing the discussion, it's helpful. I don't have an authoritative answer, because in my experience the details of exactly which point on the gas regulator or vent when measuring clearance is inconsistent. Ultimately the decision seems to be in the hands of the local code compliance inspector.

Remember that there are two separate clearance topics. One is the risk of creating an explosion by having an ignition source to close to the gas regulator vent. The other is a requirement for adequate working space around gas meters and valves and equipment.

On 2021-04-01 by John

thank you for your time to respond. I reviewed the reference but an still unclear if the distance requirements typically referenced apply to the regulator body or the opening of the vent (Assuming it is piped somewhere.) Thank you.

On 2021-03-31 by (mod)

@John,

I have seen local plumbing inspectors or gas company installers willing to approve an exception to gas meter clearances in some cases - the local official is the final legal authority.

For example, in the Town of Poughkeepsie, New York, where new gas meters are installed outside, when we built an addition to an existing home the gas meter would have ended up indoors - and would have had to be relocated. But the local inspector was satisfied with leaving the meter in place provided its vent was extended to the building exterior.

An example of this cited in local building codes can be found in New York City's "Appendix E Meters and Gas Service Piping"

E.1 General

This appendix addresses the requirements for meters and service piping, underground or aboveground, as the piping enters the building. Service piping includes fuel-gas piping, valves, and fittings upstream of the point of delivery. Service piping may include piping supplied by the gas service utility.

E.2.2

When located inside the building, each regulator shall be provided with a vent pipe that leads directly to the outdoor air. The vent pipe shall be sized according to local utility requirements. The vent outlet shall not be located under a window or any opening leading back into the premises or located below any overhang or projection. No gas regulator vent outlet shall be covered over, plugged up, or otherwise obstructed, and all gas vents shall be identified by suitable marking on the outlet on the outside of the building.

Watch out: there are additional important gas piping and meter location constraints, such as maximum distances from the service line valve to the gas pressure regulator.

Here is a complete copy of this example code:

NEW YORK CITY GAS PIPING CODE APPENDIX E [PDF]

https://inspectapedia.com/plumbing/NYC-Gas-Code-Appendix-E-Meters-and-Gas-Service-Piping.pdf

retrieved 2021/03/31 original source: https://up.codes/viewer/new_york_city/nyc-fuel-gas-code-2014/chapter/E/meters-and-gas-service-piping#E

On 2021-03-31 by John

Hello I have a buried LP tank approximate 25' from the corner of my home. At the entrance to the home there is a pressure regulator mounted on the back exterior wall with a vent extension of 6'. Presumable to move the vent away from the basement window and meter box. Question: Can I install an RV panel 50 outlet with breakers above the gas regulator if it is remotely vented? Can you point to a reference showing this? thank you.

On 2020-08-11 by Tom

I am going to "gang" a second 120 gallon propane tank with my existing 120 gallon tank (both above ground) to increase my propane capacity for a pool heater. If I place the second tank next to the exisiting tank close to the house, the second tank will be close to the clothes dryer vent for the laundry room. The vent will not be blocked, but it will be within one foot of the tank. I don't believe this constitutes an ignition source. Any issues??

On 2019-06-28 by danjoefriedman (mod)

You should ask him why he's doing that. If he's not just entertaining himself it may be that he's listening to the change in Pitch of the ringing tank as a way to get an idea how full it is getting.

On 2019-06-27 by Rita

Why beat on home gas tank when filling with the lid? The gas man does this all the time.

On 2018-01-26 by (mod) - buried LP tank within 10 feet of public foot-path

John in the article above you'll find this clearance distance sketch

https://inspectapedia.com/plumbing/Above_Ground_LP_Tank_Clearance_Distances.jpg

but of course the final legal authority is your local building and zoning department.

On 2018-01-26 by John

Please would anyone know the answer to this:
We have a little used public footpath running through our property. Can I bury an LPG gas tank within 10' of this.

Thanks

John


...

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