Eliminating Water Hammers for Good Eliminating Water Hammers for Good

What You'll Need
protective goggles
work gloves
electric drill with attachable bits
adjustable wrenches
pipes of different size
piping clamps

In a piping system, water hammers are particularly loud banging noises which occur as a result of a sudden change in the water flow velocity. It is an unpleasant and dangerous condition that should be addressed as soon as it begins to appear in the piping system. While eliminating water hammers may not be a piece of cake, it is not beyond the capacity of any homeowner with some basic knowledge in plumbing and a handy arsenal of standard maintenance tools.

Step 1–Reduce Risk of Water Hammers

Plan a piping system which will reduce the possibility of a water hammer to the minimum. Keep the water flow velocity below 5 feet per second at any given point of the system.

Step 2–Replace Pipes

Install larger pipes as to maintain the above velocity level. Therefore, inspect your current pipes and replace any inappropriately sized pipe with a new, bigger one.

Step 3–Fix Loose Pipes

Use pipe clamps or anchors to fix any loose pipe to the wall. If this does not help, install a water hammer eliminator. This is a device which is joined inline to the piping system and acts as a shock absorber.

Step 4–Cover Pipes

Cover the rattling pipes with thick cloth, e.g. a towel or an old shirt. Keep in mind, however, that this is not always possible because the pipes may be hidden behind a wall or ceiling.

Step 5–Check Air Chambers for Water

Consider installing air chambers if your piping system does not have one or more. If your piping system includes air chambers, check whether they have not been filled with water. If they have, do the following: stop the water flow from the main shutoff valve, open all faucets inside and outside the house or apartment and allow the water to drain. After you are done with the draining, turn on the main valve again – the water flow should be bypassing the chambers now.

Step 6–Prolong Time for Fluid Velocity Change

Pay attention to the time for fluid velocity change and increase it in those areas of the piping system where the velocity changes too fast. For example, you may want to replace quarter-turn ball valves, which often cause water hammers, with globe or gate valves which will slow down the fluid velocity.

Install motorized or pneumatic valves to prolong the time necessary for valve change. With the pneumatic valves, you can also mount a restriction to the exhaust vent.

 Step 7–Make Stand Pipe

Construct a stand pipe upstream of every valve of the piping system by using a capped pipe or tubing. The stand pipe should be located vertically in relation to the main line.

Step 8–Install Accumulator

If the water hammer is caused by the sudden starting or stopping of a water pump, you can eliminate it by installing an accumulator or a de-surging mechanism.

Finally, you have to familiarize yourself and observe all local plumbing standards and requirements.


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