What is a crucial factor when positioning flexible joints in a drainage system?

When positioning flexible joints in a drainage system, a crucial factor is to allow for differential movement. This is particularly important because drainage systems are subject to various stresses and movements due to ground settlement, temperature variations, and other environmental factors.

Flexible joints are specifically designed to absorb these movements, which helps to prevent stresses that could lead to cracking or failure in rigid pipes. By allowing for differential movement, such joints ensure that any shifts in the soil or pipe alignments can be effectively managed, maintaining the integrity and functionality of the drainage system. This adaptability is essential for long-term performance, especially in areas where the ground may experience significant shifting or settling.

Other factors such as increasing flow speed or accommodating temperature changes are not the primary roles of flexible joints. While they may indirectly affect the overall performance of the drainage system, their main purpose is to mitigate the effects of movement and maintain proper alignment throughout the lifespan of the installation. Reducing installation costs is also a consideration, but it should not compromise the system's resilience and effectiveness, which is paramount in drainage design.