Gas piping to water heaters can be made from which materials?

Gas piping to water heaters must be constructed from materials that can safely handle the pressures and characteristics of natural gas or propane without degrading or causing leaks. The correct answer highlights the use of black iron and galvanized steel, as both are durable and have been traditionally used for gas piping due to their strength and resistance to corrosion when properly coated.

Black iron piping is a popular choice because it can withstand high pressures and is designed specifically for gas applications. Galvanized steel, while often used for water supply piping, can also be adapted for gas use. However, it's essential to ensure that any threaded connections are properly sealed and that the pipe is free from damage.

In contrast, copper piping is not typically recommended for gas lines because it can be prone to corrosion, especially when exposed to certain types of gas, and it may not provide the same level of safety as black iron or galvanized piping. Plastic piping, while useful in some applications, is generally not suitable for gas lines due to its lower durability and potential for failure under gas pressure or heat. Rubber is also not appropriate for gas piping because it cannot withstand the conditions present and may be susceptible to degradation. Stainless steel is a viable alternative for gas piping in some scenarios, but it is not exclusively used;