What Is Water Hammer?

Yikes! What’s that Sound? You May Have Water Hammer.

All you need to know about water hammer and how to prevent it…

What is water hammer?

Water hammer occurs in plumbing systems when the water flow is abruptly stopped or from a forced change of direction, which causes the water to change course creating a sound wave (loud banging or hammering sound). It can cause damage to pipes, fittings, and appliances, and can also be a nuisance for residents or users of a building.

The resulting pressure wave can travel back through the pipes, causing a loud banging or hammering sound, and potentially causing damage to the plumbing system.

What causes water hammer?

Water hammer can be caused by a lot of factors, including:

  1. Sudden valve closure. When a valve is closed abruptly, the water flow is suddenly stopped, and the resulting sound wave causes water hammer.
  2. Rapid pump shutdown. If a pump is shut down too quickly, it can cause the water in the pipes to suddenly stop moving, creating a sound wave.
  3. Lack of water hammer arrestors.  If the anchors for the pipes along with the expansion loops and joints are in the incorrect location, these mistakes can cause water hammer.

What does not cause water hammer?

The booster system itself does not cause water hammer. Water hammer that occurs during the use of a booster system are coincidental.

How to prevent water hammer?

There are several ways to prevent water hammer, including:

  1. Install water hammer arrestors. A water hammer arrestor is a device that absorbs the sound wave created by water hammer, preventing it from damaging the plumbing system. These devices can be installed at valves, pumps, and other locations where water hammer is likely to occur.
  2. Slow valve closure. When closing a valve, do it slowly to avoid creating a sudden pressure wave.
  3. Properly installing anchors, expansion loops and compensators. Regularly checking and maintaining check valves can help prevent water hammer by ensuring they are functioning properly.

Water hammer is a common plumbing problem that can be both a nuisance and a potential hazard. Understanding what causes water hammer and taking steps to prevent it can help keep your plumbing system functioning properly and avoid costly repairs. If you experience water hammer in your plumbing system, it is important to address the issue promptly to prevent further damage.


About QuantumFlo®

QuantumFlo, A Wilo Brand, is the world leader in pumping and pump controls systems technologies. Founded in 2007, QuantumFlo is an innovator of sizing and selection applications and rules for variable speed pumping. A pioneer in “technical pumping”, they apply creativity and out-of-the-box thinking in developing and designing packaged plumbing booster systems and software. iQFlo™ 3.0 is the industry’s most intelligent B.O.S.S. (Booster Operating System Software), and the only true operating system for booster control. calQflo® is a revolutionary online platform for booster sizing and selection, allowing 100% free access from anywhere in the world with an internet connection. QuantumFlo is headquartered in Sanford, Florida in a 30,000 square foot state-of-the-art facility with a simulated testing rig. WILO USA LLC acquired QuantumFlo in 2021.

About Wilo

WILO USA LLC, a subsidiary of WILO SE, is one of the world’s leading manufacturers of pumps and pump systems for building services, the entire water management chain and industry. The company, whose sales reached more than 1.4 billion euros 2018, has its eyes fixed on the future and is heavily involved in research and development. Based in Dortmund, WILO SE is increasingly moving away from being just a supplier of components and moving towards being a system supplier. The Wilo name is internationally recognized as being synonymous with high-tech in the pump industry. Wilo employs around 7,800 employees in over 70 subsidiaries around the world. In 2017 Wilo acquired Cedarburg, WI manufacturers Weil Pump, Scot Pump and Karak Machine Co., followed by the 2019 asset acquisition of American-Marsh Pumps, and QuantumFlo in 2021.

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