Water Hammer
![WP_20140929_16_11_59_Pro.jpg](/proxy/?url=https://content.instructables.com/FC1/27H6/I0NOGUSC/FC127H6I0NOGUSC.jpg&filename=WP_20140929_16_11_59_Pro.jpg)
The drinking water line had a bang every time the tap was closed quickly. The easy fix is a cushion of air.
A 10” piece of ½” copper pipe was soldered and capped above the shut off valve. When the kitchen tap is suddenly closed, the air space acts like a shock absorber.
Replenish the Air
![WP_20140929_16_12_20_Pro.jpg](/proxy/?url=https://content.instructables.com/F48/YLVK/I0NOGUUB/F48YLVKI0NOGUUB.jpg&filename=WP_20140929_16_12_20_Pro.jpg)
Over time, the air is absorbed into the water and the space needs more. Upstream is the sand filter, which must be replaced every 3 or 4 months. When the new filter is put back in service, opening the drinking tap slowly will purged the air through the line and refill the space.