To minimize the occurrence of what issue must the flow velocity in a hydronic piping system be controlled?

Controlling the flow velocity in a hydronic piping system is essential to minimize the occurrence of water hammer. Water hammer is a phenomenon that occurs when there is a sudden change in the velocity of the fluid within the pipes, leading to shock waves that can create loud banging noises and potentially damaging vibrations. High flow velocities can exacerbate this issue because they increase the momentum of the water, which, when suddenly stopped or redirected (such as by a valve closing quickly), can cause significant pressure surges.

If velocity is kept within acceptable limits, the likelihood of these sudden pressure changes is reduced, leading to a quieter and more stable system. Effective management of flow rates typically involves balancing the system design, pipe sizes, and operating conditions to ensure that velocities remain low enough to prevent the conditions that lead to water hammer. This is particularly important in complex hydronic systems where multiple valves and fittings are present, as these can all contribute to potential changes in flow dynamics.