Changes in direction of gas pipe must be made using which items?

The correct choice highlights that changes in the direction of a gas pipe can effectively be achieved using fittings, factory bends, or field bends. This understanding is critical for ensuring the integrity and safety of the gas piping system.

Fittings are specifically designed to connect sections of pipe and allow for angle changes, making them essential for rerouting gas flow effectively. These components are manufactured to meet stringent specifications, ensuring they can handle the pressures and stresses associated with gas service. Factory bends are pre-formed, reducing the risk of kinking or damaging the pipe, while field bends are created on-site, allowing for flexibility in installation depending on space constraints or layout requirements.

The other choices, while related to gas piping, do not serve the purpose of changing direction as effectively. Welds are mainly used for joining two sections of piping and are not intended for directional changes. Couplings are designed to connect two straight sections of pipe without changing direction. Elbows, while useful for specific angles, do not encompass the broader range of options provided by fittings, factory bends, and field bends, which together allow more flexibility and adherence to safety practices in gas installation.