Harold Kestenholz
After some discussion, there is a reminder to remove the internals from the valves and flush them thoroughly. Little bits in the water line can lodge between the precision parts, making them require force to move, thereby making a hammer when they overcome the resistance and might score the internals. This is common in new construction.
Water hammer requires a large body of water to move at high velocity agains a sudden restriction, so limiting the water flow to that required by the bathroom may also help reduce hammer. A balancing valve of a sort to restrict water flow to the combined amount of toilet, shower, and sink may limit the hammer potential.
Long runs of tubing would do better to have a slight slope downward toward the fixtures. Air in lines would settle toward the inlet of the pipe run to be moved along with the water when it runs, instead of collecting at the fixture end to create bubble bounces as water follows a bubble to the valve mechanism.
