Which fitting is not suitable for a gas piping connection?

A bushing is typically not suitable for a gas piping connection due to its design and function. Bushings are used primarily to reduce the size of a pipe connection, allowing a smaller pipe to connect to a larger opening. However, in gas piping systems, maintaining the integrity and security of the connection is critical for safety and to prevent leaks.

Gas piping requires fittings that provide a secure, leak-proof seal, which is often better achieved with fittings like elbows, couplings, and unions. These fittings are designed for more robust connections that can handle the pressures and environmental conditions associated with gas transport. Additionally, gas codes and standards often specify particular fitting types for various applications to ensure safety and compliance.

In contrast, while elbows, couplings, and unions are commonly used in gas piping systems to create strong, reliable connections or facilitate changes in direction and easy disassembly, a bushing’s design does not lend itself to such security or reliability in this context. Thus, using a bushing for gas piping would not be appropriate.