Which action should be taken to prevent water hammer?

Preventing water hammer, a loud banging noise caused by sudden changes in water flow, often requires careful manipulation of valves. Closing all valves slowly is an effective way to minimize the chances of water hammer occurring. When valves are closed quickly, it can create a sudden stop in the water flow, leading to turbulence and a pressure shock wave, which manifests as water hammer. By closing valves slowly, the water flow is allowed to decelerate gradually, reducing the risk of dramatic pressure changes that result in the characteristic noise.

Maintaining constant water flow and adjusting pressure regulation settings can help manage pressure levels in the system, but these actions may not directly address the specific issue of water hammer caused by abrupt changes in flow. Opening valves quickly would likely exacerbate the problem, as it can create a sudden rush of water into a piping system, potentially leading to the same consequences that closing valves too quickly does. Thus, closing all valves slowly is the most effective method for preventing water hammer.