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Photograph of abandoned gas piping How to Identify & Report LP Gas or Natural Gas Fuel Piping Defects
InspectAPedia®  -    



  • How to Identify & Report LP Gas or Natural Gas Fuel Piping Defects
  • How to inspect, report, & correct abandoned gas equipment and old gas lighting piping & fixtures
  • Home inspection report language examples
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This document provides free sample draft home inspection report language for reporting defects in oil and gas piping at residential properties. 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.

General 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. 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. From a safe location, call your gas company's emergency line and/or your fire department. The text provided here is a working draft and may be incomplete or inaccurate.

Contact us to suggest text changes and additions and, if you wish, to receive online listing and credit for that contribution. Also see How to Report Defects in Oil Piping. NOTICE: while example report language is provided here, reproduction of this or any of our web pages or their contents at other websites or in printed documents for sale is prohibited. © Copyright 2009 Daniel Friedman, All Rights Reserved. Information Accuracy & Un-Biased Reporting are Assured for this website - see pledge link at below-left.

How to Identify & Report LP Gas or Natural Gas Fuel Piping Defects

LP Gas Regulator Installation Requirements

  • Gas regulator ground clearance: LP gas regulators should be installed at least eighteen inches above the surface of the ground. In areas of deep snow the regulator should really be above the snow level (or protected from weather)
  • Protect gas regulator from weather: the LP gas regulator(s) should not be located where they are exposed to large amounts of water (or ice) such as below a roof eave with no gutter, or close to a downspout opening.
  • Gas regulator hoods: The LP Gas regulator installed outdoors should [in best practice] have a protective hood to avoid damage from rain or (in freezing climates) ice. If an LP gas regulator is being installed horizontally, that is without pointing it's vent opening down, it must be protected by a cover, and even under the cover the vent should slope down to avoid risk of accumulating condensate and frost blockage, an condition which would be unsafe as frost or ice can prevent safe operation of the gas pressure regulator.
  • Point vents down: Where a regulator is installed outside without such protection, it is very important that the regulator is placed with its vent pointed straight down so that rain and ice do not enter and possibly block the vent - a dangerous condition
  • Distance between LP gas regulator and building openings: LP gas regulators should be installed at least five feet from any building window or vent or air intake (ten feet if a buried LP tank is in use).

LP Gas Regulator Inspection Procedure

The LP Gas regulator(s) should be inspected each time that the building receives an LP gas delivery.

  • Turn off the LP gas service valve at the tank and check for gas odors anywhere. If gas odors are present we suspect the main shutoff valve is defective and it may need replacement.
  • Check that the LP gas regulator is properly installed, sloped so that its vent will drain, and that it is protected from the weather
  • Check that the LP gas regulator vent has not become blocked. We sometimes find that insects will nest in openings on these devices, blocking the vent screen with mud or insect nest materials. Make sure the regulator vent has not become blocked with anything whatsoever.
  • Check the LP gas regulator for evidence that water has leaked into it by looking into the regulator's cover-cap (a removable cap). A service technician may also shut down the gas system and remove the regulator's adjusting screw to check the regulator interior for corrosion. It is particularly important to look for evidenceof corrosion in the pressure relief valve area inside the regulatorr, since if this component is corroded the relief valve may not function safely.
  • Gas service experts recommend replacing an LP gas regulator if it is more than fifteen years old.

LP Gas Piping Defect list and sample home inspection report language

Safety warnings about gas piping: Check condition of flexible gas line connections: Caution: we do not pull out appliances to look at gas line connections, but you should do so, checking condition of flexible connections for leaks and assuring that a shutoff valve is installed. Watch for leaks in those flex-connector lines between gas line and the appliance as they are thin wall and often corrode and leak. Gas leaks are dangerous.

Safety warning. Flexible soft copper piping has been used to supply municipal (natural) gas to the
... electric clothes dryer.
... hot water heater.
... heating system.
This is not a recommended installation and it may be prohibited by local codes - "black iron" steel piping is required in many jurisdictions.

Safety warning: Flexible ridged thin wall copper tubing has been used to supply gas to the
... hot water heater.
... heating system.
This is not a recommended installation and it may be prohibited by local codes.

Technical Violation: Flexible copper LP gas line may not be routed through walls or similar locations where it may be damaged or punctured. For these sections of routing threaded iron pipe is required. This is an usually inexpensive item to correct. You can discuss this point further with your gas supplier and your plumber.

All gas or oil piping must comply with local codes and ordinances or with the national fuel gas codes. Copper and brass tubing (except tin lined copper) shall not be used if the gas contains more than an average of .3 grains of hydrogen sulfide per 100 standard cubic feet of gas.

National Fuel Gas Code, 1988 articles 2.6.2, 2.6.3, & 3.4.2 "Piping in Partitions". Also NFPA 58 Code. See ANSI Z223.1-NFPA 54.
Residential Gas Hot Water Heater Pocket Partner - Testing and Trouble Shooting, State Corp., Ashland City, TN 37015

*** Safety Recommendation: support the loose gas lines: gas lines> additional support is needed to secure the building appliance gas supply line at
___
Loose gas lines can lead to dangerous leaks. This item should be addressed soon and should be a minor cost.

Gas Piping Maintenance Tips

MAINTENANCE TIP: Openings where the gas supply pipe enters the building should be caulked to reduce possible water or insect/rodent pest entry.

Safety Recommendation: the gas supply line at
... is not installed according to the manufacturer's recommendations. Proper iron pipe plumbing with sediment trap, also called a "drip leg" (typically at least 3" long off of a "tee" at same height as the gas control) should be installed. This is an inexpensive plumbing correction and it should corrected soon to avoid moisture damage to the gas controls. (Note that depending on the quality of the gas being delivered in some municipalities, the installation of a drip leg or dirt leg may not be required by local officials.*** Safety: gas line loose: At
...
better support is needed for the gas piping. Loose piping risks dangerous gas leaks.
... We did not observe/smell a leak at this location when we inspected. This item should be handled as soon as possible.

*** Safety:We recommend that unused gas equipment be removed and that you have the unused section of gas line properly sealed by a qualified plumber or by your gas supplier. Leaky old appliances or gas lines are dangerous.

Recommendations for use of two-stage gas regulation

Many residential LP gas installations will be found with a single gas pressure regulator at the storage tank.

A "two stage" LP gas regulation system uses two gas pressure regulators. Gas flows out of the LP Gas storage tank first through a "high pressure" regulation stage (usually installed right at the LP gas tank) and then through a second "low pressure" regulator as a second stage (usually installed close to the point of LP gas entry into the building). Two stage LP gas regulation is required for certain installations but is less often found installed at single family residential properties. Experts recommend this "two-stage" regulation of LP gas installations, particularly where large LP tanks are installed above or below ground for several reasons:

  • Large LP gas tanks will be located at a greater distance from the building
  • Two stages of LP gas regulation helps assure steady, even gas pressure at each appliance in the building, making it easier to maintain the requisite typical eleven inches of water (equivalent pressure) at each appliance. That's because the low-pressure regulator being used to deliver gas at the proper pressure for the appliances is located closer to the appliances than if it had been installed right at the more distant gas tank.
  • Two stage LP gas regulation can (slightly) reduce the LP gas system installation cost by permitting the use of smaller diameter gas piping between the first stage regulator (at the tank) and the second stage lower pressure gas regulator (at the building).
  • Two stage LP gas regulation helps avoid gas delivery system freeze-ups in climates where low temperatures are common, because the expansion rate and gas flow does not have to occur all at one place (at the final regulator). Distributing the pressure drop across two devices means less pressure drop occurs at each individual regulator device, reducing the tendency to form frost in very cold weather.
  • Use of two stage LP gas regulation permits a single high pressure line coming from the first regulator to deliver LP gas to multiple low-pressure regulators at diverse building locations, potentially improving LP gas appliance performance at a large building.
  • Service people assert that there will be fewer service calls due to loss of gas pilot flame or requirements for gas burner adjustment where two stage regulation has been employed on an LP gas piping system.

[See LP or Natural Gas Pressures for a table showing the range of variation in LP gas pressure in the tank at various temperatures.]

Testing for LP Gas System Leaks

Here we outline some common procedures used to test gas piping and fittings for leaks. These procedures should work equally well for both LP gas (propane or bottled gas) systems and for natural gas (piped-in gas from a gas utility company) systems. [NOTE: Except that LP gas and natural gas operate at different pressures and thus will have different test pressure specifications] Readers who are interested in gas leak detection equipment should review our article and gas testing warnings at Recommendations for gas measurement instruments & gas detector tubes for indoor gas level tests which includes our description of use of the TIF8800 and similar gas detectors.

Pressure testing a gas piping system for evidence of gas leaks

These two methods are generally used to test a gas piping distribution system to see if leaks are present.

  • Low Pressure Method Gas leak tests by gas service technicians generally include the following steps:
    • All gas piping connections, valves, and appliance connections and valves are inspected visually for tightness and good condition
    • A gas pressure gauge [such as the Fisher(TM) Type 50P-2 gas pressure gauge] is connected to a burner orfice
    • The gas service valve is opened to permit gas to flow into the gas piping distribution system, and then the valve is closed again, securely
    • The gas pressure gauge should read eleven inches of water column and should hold steady.
    • The gas pressure at the point of testing, say a gas-fired heating appliance, is bled off slowly until the gas pressure test instrument gauge indicates nine inches of water column.
    • The system is monitored for any pressure drop for at least three minutes. If no pressure drop is detected the system is considered not leaking.
  • High pressure gas leak method is also used by gas service technicians and includes steps similar to those above, using a special fitting [such as the Fisher(TM) Type J600 test block] installed between the service valve outlet port at the LP gas tank. The service valve is opened,as above, to pressurize the gas piping, and the system is bled down to a test pressure of 10 psig, then monitored for at least three minutes to check for a pressure drop.

Methods used to find and identify points of gas leaks in a gas piping distribution system or at a gas appliance

  • "Soap solution" tests for gas leaks: a solution of soapy water (some technicians use dish soap and a brush or rag) is the most common method used to test for gas leaks. As we noted earlier, Readers who are interested in gas leak detection equipment should review our article and gas testing warnings at Recommendations for gas measurement instruments & gas detector tubes for indoor gas level tests which includes our description of use of the TIF8800 and similar gas detectors.
  • Soap solution is applied at every piping joint or connection (or the test instrument may be used carefully at and around every connection or other suspect point) and the technician watches the soaped connection to see if soap bubbles are formed. Experts warn that this method requires some experience and care. For example, a large gas leak may blow away the solution without forming a soap bubble, or bubbles may be forming in a location which is physically hard to see.(Sometimes we can "see" around a corner or to the back side of a pipe using our TIF 8800 combustible gas detector in these cases.)
  • Soap solution is applied to lengths of piping to test for pinholes or mechanical damage if no leaks are found at threaded or flared connectors but when gas leaks are evident in the system.
  • Gas leaks at gas valves: we very often find very small gas leaks at the seamed sides of some gas valves, such as those commonly found on gas-fired domestic water heaters, especially when using the TIF 8800. These leaks can be so miniscule that they do not show up during a bubble test, and they are often present even on new valves. This may be a source of some disagreement between a home inspector, building owner, and the gas service technician, and need to be handled with some judgment, experience, and reason.

Identifying Sources of Leaks at Brass Flare Fittings on LP Gas Piping Systems

Photograph of a leaky brass flare fitting Photograph of a brass flare fitting in good condition

Here are two brass flare fittings. One of them had a gouge that gave us a gas leak that was a bit tough to find until we disassembled and inspected the leaky joint.

If tightening flared copper tubing connections does not easily correct a leak at that joint, do not just over-tighten the joint (you may break the flare and cause a still larger leak), and do not rely on pipe sealant inside of flared copper tubing fittings. Open and inspect the joint, and replace the flare fittings or make a new copper tubing flared end if necessary.

General Safety Warnings for LP or "bottled" or "propane" Gas Installations & Inspections

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:

  • Do not do anything that is likely to cause a gas explosion, such as lighting a match, operating an electrical switch, or even using a telephone in the building
  • Leave the building immediately
  • Notify other building occupants of the safety concern
  • Contact the local gas company and/or fire department

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Use links just below or at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.

GAS PIPING, VALVES, CONTROLS
  Gas BTUH & Cubic Feet
  Gas Conversion LP Natural Gas
  Gas Flame & Noise Defects
  Gas Leak Detection
  Gas Lighting Pipes & Fixtures
  Gas Meters
  Gas Piping Defects
  Gas Regulators for Appliances
  Gas Regulators for LP Tanks
  Gas Shutoff Valves
  LP Gas Tanks
  LP & Natural Gas Safety Hazards
  Natural Gas Combustion Products
  Types of Fuel Gas Source

  • U.S. Energy Information Administration - eia.doe.gov/
  • U.S. Environmental Protection Agency - epa.gov/solar/energy-and-you/affect/natural-gas.html
  • At Natural Gas.Org www.naturalgas.org/environment/naturalgas.asp#emission you’ll find a table of combustion products
  • At geocities.com/rainforest/6847/report1.html is an interesting and detailed though not “neutral” report on the components and contaminants in the combustion of natural gas. You’ll see a long long list of emissions products, but look again – most of the contaminant levels listed are in the picograms.
  • apvgn.pt/documentacao/iangv_rep_part1.pdf lists the components in natural gas exhaust from vehicles
  • The Need Project, Manassas, VA: need.org/needpdf/infobook_activities/SecInfo/NGasS.pdf
  • Kroschwitz, Jacqueline I., and Mary Howe-Grant (eds.). "Gas, Natural." In Encyclopedia of Chemical Technology. 4th ed., vol. 12. New York: John Wiley and Sons, Inc., 1993.
  • Tussing, Arlon R., & Bob Tippee. The Natural Gas Industry: Evolution, Structure, and Economics. 2nd ed. Tulsa, OK: PennWell Publishing, 1995.

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