Water hammer is caused by water going through a pipe and hitting a bend and changing direction. When water hits the pipe as it changes direction it causes a shockwave, this is the hammer sound. It's most often caused by quick closing valves on appliances such as dishwashing and clothes washing machines. But it can also be caused by the quick shutting off of water by toilet tanks and faucets in sinks, showers and bathtubs.
Most homes these days have devices called air chambers, air cushions, or water capacitors. They have chambers within them filled with air, which act as shock absorbers. These devices can become completely or party filled with water because over time the air is absorbed into the water beneath it.
Water hammer doesn't only affect water plumbing systems, it can also affect steam ones. But in steam delivery or distribution plumbing it's referred to as 'steam hammer'. In these cases, steam condenses into water in one of the horizontal sections of pipe. Steam picks up this water and sends it into a pipe connection or joint.
If water hammer suddenly starts, it's often because one or more of a home's air chambers have filled with so much water that they no longer work. It's possible that they can be repaired instead of replaced. First the waterlogged air chamber(s) must be located. The water supply needs to be turned off prior to reaching the chamber(s), then the faucets and valves ahead of the chamber(s) need to be opened to allow the water in the pipe and chamber to drain. Air will then flow into the chamber restoring it.
If the air chamber is lower than the height of the valve, more work may be needed. The main water supply lines might need to be drained too. Sometimes air chambers won't drain completely; it may be because of build-up of mineral or chemical deposits. If the chamber can't be cleaned out it will need to be replaced.
If the home's plumbing system doesn't have air chambers built into it, reducing the water pressure may be a solution, this could be accomplished with the installation of valves that reduce the pressure of the lines coming into the house. But this might not work if it leads to such low pressure that faucets and valves on upper-floors only have a trickle of water coming out of them. If pressure reduction doesn't work, it may be necessary to install air chambers into the current plumbing system. Many of the chamber devices currently on the market have a built-in valve for letting air refill. - 15224
Most homes these days have devices called air chambers, air cushions, or water capacitors. They have chambers within them filled with air, which act as shock absorbers. These devices can become completely or party filled with water because over time the air is absorbed into the water beneath it.
Water hammer doesn't only affect water plumbing systems, it can also affect steam ones. But in steam delivery or distribution plumbing it's referred to as 'steam hammer'. In these cases, steam condenses into water in one of the horizontal sections of pipe. Steam picks up this water and sends it into a pipe connection or joint.
If water hammer suddenly starts, it's often because one or more of a home's air chambers have filled with so much water that they no longer work. It's possible that they can be repaired instead of replaced. First the waterlogged air chamber(s) must be located. The water supply needs to be turned off prior to reaching the chamber(s), then the faucets and valves ahead of the chamber(s) need to be opened to allow the water in the pipe and chamber to drain. Air will then flow into the chamber restoring it.
If the air chamber is lower than the height of the valve, more work may be needed. The main water supply lines might need to be drained too. Sometimes air chambers won't drain completely; it may be because of build-up of mineral or chemical deposits. If the chamber can't be cleaned out it will need to be replaced.
If the home's plumbing system doesn't have air chambers built into it, reducing the water pressure may be a solution, this could be accomplished with the installation of valves that reduce the pressure of the lines coming into the house. But this might not work if it leads to such low pressure that faucets and valves on upper-floors only have a trickle of water coming out of them. If pressure reduction doesn't work, it may be necessary to install air chambers into the current plumbing system. Many of the chamber devices currently on the market have a built-in valve for letting air refill. - 15224
About the Author:
Brain LeMaire has served as President of CuraFlo since September 2006, before that he has worked in the pipe repair and pipe restoration industry in Vancouver, Canada as General Manager of West Coast Pipe Restoration. He just updated the Page on low water pressure
