Water hammer is also known as a hydraulic shock because it occurs when pressurised water or a fluid flow is suddenly shut off.
When the main water shut off valve in your house is shut off, it will cause a sudden drop in pressure that results in air rushing into the pipes. When this happens, you may hear a hammering or knocking sound coming from your plumbing fixtures or appliances.
This is known as water hammer.
When water is running through a pipe and is stopped abruptly, its causes a shock wave that leads to the noisy hammering on the pipe walls.
Water hammer is usually not a problem, but it can be annoying. You may also need to hire a plumber to increase pipe size or install air chambers in your plumbing system to stop the water hammer effect.There are two situations in which you may need to fix water hammer. The first is when your home's pipes and fixtures rattle because of air trapped in the pipe fittings when the main shut off valve is turned off. The second is when you have a leaky faucet or toilet that makes a hammering noise every time it turns on and off.
The most common solution for both problems is to add an air chamber, also known as an air volume control (AVC), to your plumbing system. An AVC acts like a shock absorber and greatly reduces or even eliminates water hammer noises in your household plumbing. If you prefer not to install an AVC, you can also install check valves, also called one-way valves, to prevent water from rushing into your plumbing.
If you have a leaky faucet or toilet and the noise occurs every time it is turned on and off, a check valve can also stop this problem. If your home already has an AVC installed, but the hammering noise persists, you may need to increase pipe size in your plumbing system.
Another approach to stopping water hammer is to use shorter lengths of straight pipes. You can improve this technique by installing shorter branch pipe lengths with more elbows fitted in the water pipes. Elbows reduce water hammer by breaking down the pressure waves that form due to hydraulic shock.
Your plumber can also add expansion loops along the straight pipe. Looped piping slows the flow velocity in the water system. Decelerating the fluid velocity slows the water flow preventing water hammer.The best way to identify and fix water hammer problems is by calling a plumber who has experience installing rigid piping systems such as copper or PVC. A plumber will come to your home to inspect all of your plumbing fixtures and appliances for leaks and cracks that cause water hammer noises. Your plumber may recommend installing an air chamber with flexible tubing rather than rigid piping if minor repairs cannot solve the problem. A plumber will also adhere to the pipe sizing charts guidelines. These pipe size guidelines help limit or avoid water hammer problems.
If you have never noticed a water hammer in your home before but suddenly hear it when the main shutoff valve is turned off, there may be a leak in one of your plumbing fixtures or appliances.
In this case, an air chamber will not fix the problem. Instead, you need to inspect all of your household plumbing fixtures and appliances for leaks and cracks that may produce water hammer noises. Depending on the type of piping material used in your house such as copper pipes, galvanised steel, or plastic, you may also need to replace some pipes with larger-diameter pipes to decrease water pressure and provide better cushioning against water hammer noises.If your water supply line is connected to a pump, a sudden power loss or a pump failure causing it to stop working will also cause the hydraulic shock. When the pump stops working, water will change direction suddenly. This sudden drop of pressure will cause the water hammer.
Adding an AVC does not always solve every water hammer problem. To stop the knocking and clanging noises in your plumbing, you may need to replace some pipes with larger diameter pipes or add new piping altogether.
The best way to identify and fix water hammer problems is by calling a plumber who has experience installing rigid piping systems such as copper or PVC. A plumber will come to your home to inspect all of your plumbing fixtures and appliances for leaks and cracks that cause water hammer noises. Your plumber may recommend installing an air chamber with flexible tubing rather than rigid piping if minor repairs cannot solve the problem.
If you have a lot of noisy plumbing fixtures and appliances, but not all of them are connected to each other with copper, steel, or plastic pipe, consider replacing non-metallic piping materials, such as PVC or CPVC, with metal pipes to provide a more effective shield against water hammer noises in household plumbing.
A lot of noise could also mean you have a problem in your main water line. If all the fixtures in your home are making noises, there is either a blockage in a drain or damage somewhere in the main water line running between your house and the wastewater treatment plant. You should hire a plumber to investigate this further for you.The leading cause of most water hammer problems is too much air pressure in your plumbing system--not just when the main check valve is turned off, but when it is turned on. To eliminate water hammer problems, you need to identify the source of air pressure in your home's plumbing system. You may have an air compressor connected to the water main line that is causing high air pressure in your house's pipes. An air compressor with too much PSI can cause a lot of noise when water enters or exits any fixture or appliance connected to it. If this is the case, you will need to hire a professional plumber with expertise installing piping systems for homes who can find and fix the problem. Reducing or eliminating airflow into your home's system will stop automatic opening valves from adding extra pressure to fixtures and appliances when they are turned on, which usually stops shock waves from pushing through your plumbing lines and producing unpleasant noises. The loud banging caused by the water hammer can be noisy, but it is not usually a serious problem. If you have a water hammer in your home's plumbing system, check all of the appliances and fixtures that are connected to copper or plastic piping for leaks or damage around their joints. All other types of flimsy pipe should be replaced with metal piping material to reduce air pressure inside your house's main water line.
If you are still having trouble solving the problem on your own, you may want to consider hiring a professional plumber who has experience working with rigid piping systems such as copper or PVC. Your plumber will come out to inspect all of your plumbing fixtures and appliances for leaks and cracks that produce water hammer noises and replace them with water hammer arrestors, which are directional air chambers that help stop the flow of water in your home's plumbing line when pressure spikes.
A water hammer arrestor, also known as a shock absorber, is a device installed on your home's system to help stop the flow of water in your plumbing line when it experiences a pressure surge from appliances and fixtures that create too much momentum. Water hammers can occur at any time, when you turn on or off a faucet or use the toilet, for example. When this happens, high-speed waves of water move throughout your pipes and wreak havoc with plumbing lines and home appliances that are connected to them. To prevent damage from the pressure wave of moving water that causes a water hammer noise, the installation of a shock absorber will reduce the flow through your home's system whenever immediate pressure change occurs anywhere along your main water line. Water hammer causes noise because the air inside your plumbing system is compressed when water suddenly changes speed or direction. A shock absorber installed on your home's system will absorb that change in momentum and prevent pressure from building up in your pipes when a faucet is turned on, for example. When you turn off the main valve and begin to fill a sink with running water, for instance, it creates excess pressure in your line when there is no immediate release of that pressure through the faucet. A shock absorber allows air compression when extra pressure builds up in your line but prevents wave action by releasing all of the built-up air when you turn off the faucet stopping excess noise in your system. Water hammer arrestors are extremely important in homes where occupants use appliances such as washing machines and dishwashers. Washing machines have a water shut off system that cuts water flowing into the unit in seconds. This sudden stoppage of the water supply causes water pressure changes when the units are turned on or off. They will also help reduce the noise caused by air compressors installed on the main water line and generate waves inside your plumbing system when high-pressure air enters the house during appliance operations.
A professional plumber can easily install an air chamber for water hammer/shock absorber to stop noise in your home's plumbing systems whenever appliances or fixtures create shock waves throughout your piping system because it is difficult to reach certain areas of pipelines without taking apart walls. An air chamber is installed directly on your home's plumbing line to stop noise in your line when appliances or fixtures create water hammer. A water hammer arrestor installation involves cutting away some of the piping behind your home's main shut-off valve, inserting an air chamber, and then reattaching the piping again with solder once it has been properly inserted. A plumber can also install one inside an appliance, such as an air conditioner that causes excess pressure in the home's system whenever it shuts off. Air chambers are most commonly found along main water lines, but they can be placed anywhere within five feet of your plumbing fixtures to reduce noise throughout the house whenever excessive pressure occurs.