Final answer:
b. Instantaneously closing valves. Water hammer is caused by the instantaneous closing of valves in a plumbing system. It can create loud banging sounds and potentially damage the plumbing. Water hammer can be prevented by installing water hammer arrestors and ensuring proper pipe support.
Step-by-step explanation:
Water hammer is caused by the instantaneous closing of valves in a plumbing system. When a valve is suddenly closed, the flow of water is abruptly stopped, causing a pressure wave to travel through the pipes. This can create a loud banging sound and potentially damage the plumbing system. Loose pipes can also contribute to water hammer as they can vibrate and amplify the pressure surges.
To prevent water hammer, you can install water hammer arrestors near the valves. These devices contain a cushion of air or gas that absorbs the energy of the pressure wave, preventing it from causing damage. Proper pipe support and securing can also help reduce the occurrence of water hammer.