Which type of pipe is commonly used in gas piping systems due to its strength?

The choice of black iron pipe for gas piping systems is due to its excellent strength and durability. Black iron pipe is designed to handle high pressure and is resistant to breakage, making it an ideal choice for transporting natural gas and other gases safely. Its robustness helps in preventing leaks, which can be critical in gas applications.

In contrast, while PVC pipe is widely used for various applications due to its corrosion resistance and lightweight nature, it is not suitable for gas because it cannot withstand high temperatures and pressures associated with gas transport. Flexible gas lines, although convenient for certain applications, typically are better suited for lower pressure situations or for specific applications rather than mainline gas piping. Copper pipe, while also strong and resistant to corrosion, is generally more costly and often used in smaller, specific applications instead of main gas lines. Therefore, black iron pipe stands out as the preferred choice for gas systems due to its strength and reliability.