I am plumbing a small bathroom. The total number of supply lines is five — shower (hot and cold), sink (hot and cold) and toilet.
I want to place hammer arrestors but I'm not sure if I need 5 hammer arrestors, or if I can just place two for the sink, or if I should place them as the pipes enter the room, and protect the whole room that way.
All the diagrams on the internet indicate placement as close as possible to the faucet.
The total length of pipe from where the pipe enters the room until the furthest faucet is only about 10 feet. Total including verticals.
I'm attaching my poorly drawn sketch of the plumbing. The arrestors are "orange". Should they g near each tap or can they go as the pipes enter the room?
Best Answer
Put them near the sink.
Water hammer is caused by the inertia of the moving water in the water lines trying to keep moving when a valve shuts it off suddenly - so placing them at the far end of lines is most effective.
In "typical" bathroom fixtures of the current era, the sink is also the most likely to be a "quick" shutoff (which is the most prone to causing water hammer.) Valves that shut more slowly allow the water to slow down as the valve is closing, whereas those that close quickly get to all the way shut while the water in the pipes is still moving.