What you should know about the gas pipe in your home.
When inspecting homes we see different types of gas lines used in the interior of the home which include black iron, galvanized steel, brass (containing not more than seventy-five (75) percent copper), copper and CSST (flexible piping). All of these gas pipe types were acceptable at some point in time. However, standards change and now galvanized pipe is not recommended for use as gas pipe due to the possibility of the galvanized coating flaking which could damage appliances and plug up valves or orifices.
Today we see more copper and CSST gas pipe than black iron primarily because the of cost of black iron piping is significantly more. Both rigid (types K, L or ACR) and soft copper can be used for gas lines. You can tell the difference between copper piping that is used for water and gas primarily by the type of solder joint at the connections of fittings and pipe. Water lines are typically joined together with soft solder which tends to be shiny, while gas line joints are brazed together with silver solder which tends to have a darker appearance. See fig.1 Because of the similarities it is important that your gas pipes be repetitively painted yellow every three to four feet and in some cases labeled “GAS” for identification and safety reasons. The last thing you want is someone to accidentally tap into a gas line thinking it’s a water line.
CSST is also known as Corrugated Stainless Steel Tubing (CSST) which is a flexible, safe to use with both natural gas and propane in residential, commercial and industrial structures. CSST is typically coated with a protective yellow jacket or black arc resistant protective jacket. CSST Safety says:
“CSST must be properly installed. CSST must be installed by a qualified professional and in accordance with the Manufacturer’s Design and Installation (D&I) Guide, which now expressly includes bonding and grounding of the system.”
CSST as with all other types of gas piping must be properly supported. The primary advantage of this type of gas piping is reduced labor/cost to install it. Plus most fittings can be eliminated making it less invasive for retrofit applications with finished basement ceiling. CSST should not be used to connect directly to any appliances. Connections to appliance should be made with an approved flexible connector or rigid black iron pipe.
We recommend that all gas pipe be installed by a professional contractor, CSST by a manufacturer certified contractor and CSST bonding be performed by a licensed electrician. All houses that have any type of gas appliances or fireplaces should have at least one carbon monoxide detector. If you think you smell gas get out of the building and call your local gas utility company or Dial 911 ASAP.