Which of the following is NOT a recognized method to join gas piping?

Which of the following is NOT a recognized method to join gas piping?

• A. Weld
• B. Solder
• C. Flared
• D. Threaded

Answer: (B)

In gas piping, joints must be made with proven, code-approved methods that stay leak-tight under pressure and over time. Soldering is not recognized for gas service because soft solder joints are not durable enough for the demands of natural gas and propane systems. They can creep, crack, or fail with temperature changes, vibration, or pressure fluctuations, and flux residues can contribute corrosion or leaks. For gas piping, the accepted methods include welding for steel pipe, and flare or threaded joints for copper and other compatible materials, each providing a strong, reliable connection that the code specifically requires. Therefore, soldering is the method not recognized for joining gas piping.

In gas piping, joints must be made with proven, code-approved methods that stay leak-tight under pressure and over time. Soldering is not recognized for gas service because soft solder joints are not durable enough for the demands of natural gas and propane systems. They can creep, crack, or fail with temperature changes, vibration, or pressure fluctuations, and flux residues can contribute corrosion or leaks. For gas piping, the accepted methods include welding for steel pipe, and flare or threaded joints for copper and other compatible materials, each providing a strong, reliable connection that the code specifically requires. Therefore, soldering is the method not recognized for joining gas piping.