The beginning of October means many homeowners living in the northern part of the country will have to start firing up their heating systems. Natural gas is among the least expensive and most efficient ways to fuel a furnace or boiler. Along with its advantages come safety concerns and responsibilities for homeowners. As a home inspector, it is your job to help identify deficiencies that can compromise the safety of occupants in homes using natural gas. We will discuss some of the basics of inspecting gas piping.
Supply, branch and drop lines or risers
The piping inside the house is called the gas supply line or building line. Branch lines run to individual appliances. The branch line terminates in a drop line, which is a vertical pipe dropping down to the appliance from an overhead branch line. This drop line is called a riser if it carries gas up to an appliance from a branch line below the appliance.
Sediment trap, dirt pocket or drip leg
At the appliance connection point, there usually is a sediment trap or dirt pocket, sometimes called a drip leg that includes a nipple and a cap. This pipe extension usually is at least 3 inches long and is intended to catch any water or foreign material that may be in the gas before the material gets into the appliance itself. This is simply a gravity system, with the solids and liquids falling into the pocket.
