What Is A Water Hammer?

Have you ever heard about water hammers or experienced the issue in your commercial or residential property in Brisbane, Australia? This article provides in-depth details about water hammers, their causes, effects, and how to prevent them.

Water Hammers: What Are They?

Water hammers occur in a piping system featuring valves that control steam or water flow. They result from a high-pressure shockwave or pressure surge propagating through a piping system when the water or steam in motion is forced to stop or change direction abruptly. The shockwave, or a hydraulic surge or shock, is usually characterised by a knocking sound or loud banging on your pipes immediately after shutoff.

A water hammer happens when an open valve closes suddenly, slamming the water into it. It might also occur when your water pump shuts down unexpectedly and the flow reverses to the pump. Because water is incompressible, the impact of the water causes a shock wave.

Causes of Water Hammers

Here are some of the significant causes of water hammers.

Loose pipes

Even the slightest shockwave could lead to loud bangs if your pipes are not adequately secured. This is why it is necessary to have all the pipes attached correctly to a firm surface every few metres.

It's also important to understand that you might have hidden pipes under your home's woodwork or floor. As a result, check all the loose joists, straps, or bolts in these. The most common area where loose pipes are found is in an airing cupboard or cellar.‍

Note: If any construction or renovation work is done on your property, it could also loosen the water supply pipes, increasing the probability of a water hammer.‍

New appliances

If you start hearing the bangs after new appliance installation, like a dishwasher or washing machine, the water hammer will likely be caused by the solenoid valves. This is because solenoid valves control the water supply in washing machines and dishwashers. These devices are electrically operated and stop water flow instantly. When this occurs, the water flows back up the pipes creating a shock wave that leads to the bang.

Damaged stop valves

The water hammer might also be a result of worn-out stop valves. These valves, also known as check valves, could lead to water hammers if they have loose gland packing or worn washers. The valve opens when the water hammer shock wave moves through the piping system, and the shockwave could rattle a loose jumper and the valve handle.

Clogged air chambers

If you have never experienced a water hammer in your property, but it suddenly occurs, chances are that your air chambers are blocked. In this case, the chambers get clogged with residue or water from minerals or other sediments in the water. The blockage then stops the air chamber from absorbing the pressure in your system, leading to the occasional bangs.

Water ripples from the water tank

Another major cause of water hammers is water ripples caused by a float valve inside your hot water system. The valve rocks up and down when water flows into the water tank.

This forces the valve to constantly close and open, creating a wave system that echoes along the pipes, causing the hammering sound. Plastic water tanks flex considerably, so they must feature a reinforcing plate to stop the movement.

Fast-acting valves

Water hammers might also result from fast-acting valves on your appliances, such as dishwashers or washing machines. If this is the case, the valves stop the water from moving along the pipes, suddenly resulting in a shockwave. The shockwave causes the pipes to shudder, which leads to banging. The bangs can get worse when the valves get worn out.

Effects of Water Hammers

You must get the water hammer issue dealt with immediately to avoid problems with your property's plumbing system. Here are some of the significant effects of water hammers.

Flow metre and pressure gauge damage

A water hammer could damage your pressure gauge even if the latter is set to the correct levels and working correctly. The resulting shockwave from the pressure shoots straight to the pressure gauge when it goes up to a damaging level. This could, in turn, damage your flow metre and pressure gauge.

Blown diaphragm

A blown diaphragm could be caused by severe pressure accompanying the water hammer effect. In a pressure tank, the diaphragm separates water and air. The pressure system can no longer regulate water flow if the diaphragm blows.

Gasket damage

Pipe joint gaskets are not designed to withstand high levels of water pressure. Therefore, when water hammers occur, the gaskets could weaken and become damaged.

Erosion

With time, constant water hammers could end up in your piping system, thus deteriorating them. This is because the water or condensation erodes the pipes, weakening them and thinning the material, allowing for water leaks. Erosion also weakens the joint where the pipes are joined, making them unstable and making them burst at the seam.

Burst pipes

A water hammer could also result in pipe ruptures. This occurs if your pipes are not designed to handle the sudden pressure and instead burst or crack. The bursting might also happen when the pipe joints weaken from the stress caused by hydraulic shock.

Water hammers might also result from physical pipe vibration. If the water pressure is too much and the pipes are too weak, the vibration could lead to banging pipes with high risks of bursting. A pipe burst or rupture is the most severe effect a water hammer could have on your commercial or residential property, as they are costly to repair.

How to Stop Water Hammers

If you experience a water hammer on your commercial or residential property, you shouldn't ignore it because it could adversely affect your property. Here are some of the methods utilised to stop water hammers.

Release the air pockets

One of the significant causes of a water hammer is the air pockets in your piping system. If the bang starts when you turn your pipes on, the air pockets cause the hammer.

To solve the issue, you should begin with the taps nearest your water system metre by turning them on individually. Then turn off all of them in reverse order. This helps release the air pockets in the pipes stopping the water hammer.

Close the water valves halfway

This may offer a short-term solution to your water hammer problems, but it works while you can find a long-term solution. Water hammers could also be caused by dishwashers or washing machines when the shutoff valves close instantly. To resolve this, you could temporarily solve the problem by turning the intake valves on halfway.

Intake connections replacement

You could swap the hoses for the intake connection with wider ones for the same problematic appliances.

Installing water hammer arresters

You could also stop water hammers by installing arresters which you could purchase from your local hardware store in Brisbane. You could have them installed at the cold water outlet. The arrestors are perfect for dealing with water hammer problems if several appliances are connected to similar taps.

Secure your pipes

If the noisy water pipes causing the water hammer are accessible, you could secure them onto the walls if they are loose. Securing the pipes ensures that they don't move, thus preventing the occurrence of water hammers.

Installing pressure-limiting valves

If the water hammer is caused by high pressure, your plumber could help by installing a pressure limiting valve on your water metre.

Install different taps

Often, water hammers might result from the new, contemporary mixer taps that help instantly shut the water with one flick. You could stop the problem by replacing them with soft close taps.

Call a Plumber to Fix Your Water Hammer Issue

To get a long-lasting solution to your water hammer problem, the best option is to hire a professional plumber to fix the issue. Expert plumbers have the knowledge and skills to diagnose the cause of the problem and solve it. They also apply the proper techniques to diagnose and repair the problem, thus offering a long-term solution.