Natural gas is a fantastic source of energy for our homes. It can be used to dry clothes, cook foods, provide warmth, and heat our water. More uses for natural gas are being developed as it burns clean compared to alternative fuels and in recent years has been relatively inexpensive.
Gas delivery to our homes has changed little in the last half century since it has become common in many areas. High pressure main gas lines travel alongside municipal services and individual branches are delivered to each house or building for internal distribution.
The gas service to our home starts at the gas meter. When we look at the gas meter located at our homes, we are actually observing typically three devices:
- Gas Meter - Gas is sold to us by volume and this volume is measured and displayed for the utility company by the gas meter.
- Main Gas Shutoff - All gas supplied to the home can be turned off by a shut-off valve located before the meter. This allows for maintenance of the meter and home gas lines but is also a safety turn off in case of a gas leak in the home. In the event of a gas leak nobody should be in the home looking for a turn off.
- Pressure Regulator - Gas distribution companies need to maintain very high gas pressures in the main lines to deliver enough gas to all homes and businesses on the line. These pressures are too high for our gas appliances and can fluctuate with community demand. Pressure regulators attached just prior to the gas meter regulate the pressure to the meter and home.
Gas Line Materials
Gas lines from the street to our meter are most often underground. These underground lines can be metal piping but more commonly is plastic which is less susceptible to corrosion. Plastic gas lines are buried with a parallel ‘tracer’ wire which allows utilities to find the buried lines if work is being performed near them. This tracer line is often visible where the pipe emerges from the ground.
Inside our homes, there are three common materials for distributing gas:
- Black Iron - Raw black iron with threaded fittings is the most common material found in homes build prior to the 2000‘s. Plain black iron does not react with the chemicals in natural gas and is durable against accidental nail punctures and mechanical damage. Black iron is labor intensive to install as each segment needs to be cut, threaded, and joined precisely with no flexibility of the material.
- Unsoldered Copper - Copper lines have an advantage over black iron in that the material has flexibility and can be installed from rolls with less joints while still offering some resistance to mechanical damage. Joints must only use pressure fittings as solder will react to the gas and develop leaks. In order to distinguish copper gas lines from copper water lines, yellow tape or markings must be on the copper lines at least every 6’.
- · Flexible Stainless Gas Lines - With copper becoming very expensive and black iron installations very labor intensive, a third popular alternative has become flexible stainless gas lines. These lines have a corrugated stainless steel tube wrapped in a yellow plastic ‘jacket’ and use brass fitting connections. This material requires additional protection from accidental nail and screw damage in the form of striker plates on studs where the piping passes behind.
Natural Gas Leaks
Natural gas leaks are a major concern as gas and air in the right quantities are explosive. Leaks can develop from exterior line corrosion (rust), incorrect use of materials (soldered copper), mechanical damage, or galvanic reactions (read our article on galvanic reactions on Facebook--siteprohominspections).
Natural gas is odorless and colorless so a chemical additive is put in with gas that has a smell similar to rotten eggs. If you smell a gas leak, always exit the home immediately and call the gas company or 911 for help from your cell phone outside or a neighbors’ (don't use a phone, doorbell, or other electronics as they could cause a spark). Don’t worry about finding a wrench to turn the gas off, the gas company will bring one and then you can call a plumber for repairs.
What a Home Inspector Looks for with Gas Lines
During a SitePro Home Inspection, SitePro inspectors are looking at the visible gas delivery system in the home from the ground where the gas line comes out of the ground right to the appliance itself. SitePro Inspectors are looking for the correct materials, regular maintenance, and quality of installation including:
- · Pressure valve air vent free of obstructions
- · No scent of gas at meter or internal lines
- · Gas lines protected from corrosion in damp environments
- · Correct gas line supports to avoid galvanic reactions
- · Branch Shut off valves nearby appliances
- · Appliances safely connected to gas lines
- · Correct connections of materials
- · Electrical grounding and bonding
- · Drip leg in place to catch debris near appliances
Gas lines in our homes allow us to distribute convenient energy but caution must be exercised as gas is flammable and in the right concentrations explosive. It is important that we monitor our gas lines regularly and do pro-active maintenance to keep them leak free.
If you are unsure of the condition of your gas distribution system or are concerned about any possible leaks or maintenance, contact a SitePro Home Inspector or plumber to review your system so you know your home is safe and solid.
Van Hibberts, CMI
Certified Residential Building Code Inspector ICC-5319905
Florida-State Certified Master Home Inspector Lic. #HI89
Florida-Certified Wind Mitigation Inspector
203(k) FHA/HUD Consultant #A0900
WDO Certificate #JE190791
362 Gulf Breeze Parkway, #214
Gulf Breeze, Florida 32561
850.485.3209 (Cell / Text Msg)
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