Mechanical joints should not be used on annealed temper copper tube larger than what size?

In the context of the North Carolina Mechanical Code, mechanical joints on annealed temper copper tube are restricted for larger sizes to ensure the integrity and safe operation of plumbing and mechanical systems. The choice of 7/8 inch represents the maximum size where mechanical joints can still function effectively without compromising the strength and reliability of the joint.

Using mechanical joints on larger tubes can pose significant risks, as the forces and pressures involved in systems utilizing copper tubing increase significantly with size. For tubes larger than 7/8 inch, welded or brazed connections are recommended, as these methods provide a more robust and durable connection that can withstand high pressures and thermal dynamics.

The specifications around mechanical joints are in place to prevent potential leaks, failures, and safety hazards that may arise from using an inappropriate connection method for larger diameter tubing. Thus, adhering to the maximum size of 7/8 inch ensures that all systems remain within safe operational limits while maintaining compliance with the building code.