Do you sometimes hear a dull noise, like a shock, when you turn on or turn off the water from a tap? The pipes tremble, the whole system seems to protest under the battering of an invisible enemy… That’s the water hammer. It is essential to protect your pipes against overpressure, otherwise your heating system will be damaged. The best solution: install an anti water hammer system.
Water hammer, what is it?
A little physics lesson? The movement of water circulating in your pipes is subject to a certain inertia. When a valve or tap opens or closes, causing a sudden change in the flow, this inertia is transformed into an overpressure wave. It is this wave that slams and shakes your pipes. The noise is sometimes violent, as if a disgruntled ram was banging its head in the pipes! We are talking here about water hammer hydraulic.
There are also water hammer thermal, caused by too great a temperature difference between the cold pipe and the hot steam. Condensation creates particularly loud calls for air in the pipe. It should also be noted that the accumulation of limestone or residues in the pipes is an aggravating factor.
Most of the time, water hammer is caused by a household appliance (washing machine or dishwasher, for example) or heating equipment (boiler or radiator, etc.). If left unchecked, this angry ram could screw up your heating system! Clearly, these noises and tremors signal a danger. Subjected to overpressure, domestic pipes risk breaking, causing a major water leak…
Repeated water hammer: what are the risks?
Water hammer is a threat to your installation. During a water hammer, the water pressure can rise to 40 bars (against 4 bars usually). This shock wave severely abuses the entire installation, water network and heating.
- In the long run, the pipelines end up deforming. This is what causes certain muffled noises, which are already a warning signal. Under pressure, a pipe can rupture and cause water damage.
- The fittings loosen, causing leaks.
- The membranes expansion vessels can rupture.
To stop the pressure, several solutions:
Do not let your installation suffer longer water hammer, it will end badly. If there are several solutions to reduce the pressure, the most effective is the installation of an anti water hammer system.
- Install a pressure reducer overhead installation helps prevent dropouts and pressure variations. If you only have occasional water hammer this may be enough.
- From the moment of construction, it is a good idea to size the installations in such a way as to reduce speed of water circulation.
- Install solenoid valveswhich are slow-closing valves, reduce the pressure.
- You can also install a anti-pulsation bottle which absorbs shock waves.
- Another trick: loosen the collars, enlarge the seals that are too narrow, to limit the effects pressure.
The best solution, however, is to install a device water hammer. By damping the shock wave, it effectively protects the pipes and at the same time the heating system.
The anti-ram, how does it work?
The anti-water hammer is a hydropneumatic device intended to absorb the shock waves linked to the overpressure and to regulate the speed of the water. This accessory is attached to the general water supply or one of the inlets. The anti-water hammer system is installed near the origin of the shock wave, for example on the water inlet of a washing machine.
There are two types, both equally effective. To know which one to use at home, ask a professional for advice. It will tell you which device to adopt and what size to plan for your needs.
The spring arrester
In the stainless steel spring there is a waterproof membrane. When the water cuts off, the system collects the overflow of pressure. No water hammer! The entire network is thus protected.
Membrane water hammer arrester
This device consists of a small stainless steel tank and a tight membrane stretched in the middle. The water fills the bottom of the tank and the membrane absorbs the excess pressure by deforming.
Install a water hammer arrester: where and how?
As we have already seen, this system is installed near the shock waves that it must attenuate. This is where it will work effectively.
- A water hammer arrestor must be installed between the tube valves and the device responsible for the shock wave (for example the washing machine). We install it the nearest possible of the device’s quick-closing valve.
- It arises in derivationon the hot and cold water supply.
- If your installation is subject to water hammer from several sources, do not hesitate to install various anti water hammer systems. For each cause of pressure its anti-water hammer.
- To ensure that the anti-ram arresters remain accessible, it is advisable to position them behind a sign access.
- Installer an anti-water hammer is quite simple and requires no specific tools. To connect it, use a male or female end and fix it on the tap with a thread.
- We do not install anti-water hammer on all the pipes! Don’t even think about it for a water drain. This system is reserved for faucets.
- A water hammer arrester can be installed during construction or at any time if the need arises.
An incorrectly sized or incorrectly installed water hammer arrester can also end up causing water damage! So take the time to take advice to choose the device best suited to your needs.