Which plumbing connection is used to allow the expansion of pipes?

The use of a flexible coupling allows for the expansion and contraction of pipes that occurs due to temperature changes. When pipes heat up, they expand; when they cool down, they contract. A flexible coupling provides the necessary flexibility to accommodate these changes, thereby preventing stress and potential damage to the pipes and the plumbing system as a whole. This type of connection can absorb the movement without compromising the integrity of the joint or creating leaks.

In contrast, joint connections, PVC glue, and welded connections are designed for secure and rigid attachments between pipe segments. These methods do not allow for any movement or expansion, which can lead to cracking or failure of the connection under varying thermal conditions. Therefore, flexible couplings are specifically engineered to address the need for dynamic movement in plumbing systems.