Which type of pipe is commonly used for gas lines?

Black iron pipe and polyethylene pipe are commonly used for gas lines due to their specific properties and suitability for gas transportation. Black iron pipe is durable, can withstand high pressure, and is resistant to impacts, making it a traditional choice for natural gas and propane distribution. It can handle the environmental stresses associated with underground installation and has a proven track record in the industry.

Polyethylene pipe, on the other hand, has become increasingly popular for gas lines, particularly for underground installations. It is lightweight, flexible, and resistant to corrosion, which enhances its longevity. Additionally, polyethylene's ability to be fused together reduces the risk of leaks, making it safer for transporting gas.

In contrast, PVC pipe is not approved for gas lines due to its inability to withstand high temperatures and pressures associated with gas; it's primarily used for water drainage and venting. Copper pipe, while used in some plumbing applications, is not typically used for gas lines because it can be subject to dezincification and is not as resilient against electrical and corrosive elements as black iron or polyethylene. Galvanized pipe is also not preferred for gas lines because of risks related to rusting and clogging.

Understanding the properties and applications of these different types of piping can help in selecting the appropriate material