What type of valve must be installed to protect quick closing valves on water lines?

The installation of a hammer arrestor is crucial for protecting quick closing valves on water lines. Quick closing valves can create a sudden change in water flow, which generates pressure surges or water hammer. This phenomenon can lead to significant stress and potential damage within the plumbing system, including pipes and fixtures.

A hammer arrestor works by absorbing the shock waves caused by the rapid changes in water pressure. It is typically a sealed chamber that contains air or gas, which compresses when a surge occurs, thereby mitigating the force of the water hammer. By incorporating a hammer arrestor into the system, the integrity of the plumbing is preserved, reducing noise and prolonging the life of the components involved.

In contrast, other options such as air chambers can provide some level of pressure alleviation but are generally less effective for ongoing protection compared to hammer arrestors. Check valves and shut-off valves serve different purposes, primarily related to flow direction and flow control, rather than directly addressing the issues caused by quick closing valves and the resultant water hammer.