In what situation should expansion joints be installed?

Expansion joints are designed to accommodate thermal expansion and contraction in piping systems. When pipes heat up or cool down, they can expand or contract significantly. In horizontal piping, this movement is particularly critical because it can lead to misalignment, stress on the pipe joints, and potential damages if the piping system is not able to flex and absorb these changes.

Installing expansion joints in horizontal piping that exceeds 20 feet is standard practice to prevent such issues. The 20-foot threshold is often recognized in plumbing codes as a point at which the potential for excessive thermal movement increases, necessitating some form of flexibility in the system. This helps maintain the integrity of the piping and ensures that it functions effectively without risk of failure or leakage.

While vertical piping can also expand and contract, the dynamics of vertical piping often allow for different types of support and movement compensation. Similarly, every joint connection does not require an expansion joint because the structural characteristics and arrangements can accommodate thermal changes without dedicated joints. Insulated pipes can also expand and contract, but the insulation's primary purpose is to manage temperature, not necessarily to address the necessity for expansion joints.

Thus, the installation of expansion joints is particularly crucial for horizontal piping that exceeds a certain length, where thermal expansion is anticipated to occur