Which type of joint allows for movement in a water distribution system?

Flexible joints are designed specifically to accommodate movement within a water distribution system. These joints allow for slight shifts, expansion, and contraction that can occur due to temperature changes, ground movement, or pressure fluctuations. This flexibility helps to reduce the risk of damage or failure in the piping system by absorbing stresses that would otherwise be transferred through rigid constructions.

In contrast, restrained joints are intended to prevent movement and are utilized in areas where pipe stability is paramount, like in high-pressure environments to maintain structural integrity. Welded joints create a rigid connection that does not allow for any movement or flex, making them suitable for applications where strength is essential, but not beneficial when movement is a factor. Rigid joints, similarly, do not permit any movement, ensuring that the pipeline remains fixed in place but potentially at risk of stress-related failures due to environmental changes.

Thus, flexible joints play a crucial role in maintaining the durability and efficiency of a water distribution system by allowing controlled movement, ensuring longevity and reliability in the system's operation.