The pressure reducing valve may be used for water hammer protection under properly defined conditions. The water hammer events are so fast that the relief of pressure by this means requires very special rapid response valves designed for the particular system.
Because water hammer is most often caused by water pressure that's too high, the first step is to reduce the water pressure if possible.
When valves close too quickly, the inertia of the water in the pipes causes a buildup in the force against the valve, causing a hammering sound to propagate through the pipe. You can simply install water hammer arrestors at the problematic appliances.
Install air chambers
Air chambers are also an effective solution to water hammer. These systems consist of a short segment of pipe with an empty/air filled chamber that cushions shock waves. This reduces the size of the shock waves downstream of the valve.
Preventing Water Hammer
Silent or spring-assisted check valves, on the other hand, are fitted with an internal spring that silently moves the valve into closed position before flow reversal, thereby reducing or eliminating the possibility of water hammer. Air chambers are also an effective water hammer solution.
Anticipating Water Hammer Before It Happens
At times, there is simply too much air in the pipes, which can happen upon opening the water valve. The problem and noise, caused by too much pressure, usually starts with the rapid closure of a valve.
Non-return valves that stop water hammer
INOXPA non-return valve 72700 stocked by BM Engineering is designed specifically to prevent both loss of pump prime and water hammer.
This can be fixed by draining your plumbing system, which requires turning off the main water valve and opening the highest faucet in your home. Then drain water from the lowest faucet. The chamber should fill up with air once the water is drained and resolve your water hammer problem.
Drain your pipes and refill them to create new air chambers
To do this, shut off your home's main water valve, then open the highest faucet in your home. Next, turn on the lowest faucet in your home and keep it on until all water has drained. Finally, reopen the main water valve to refill your pipes.
If an arrester doesn't eliminate the water hammer, reduce peak flow by partially closing the water-supply valves. The washer will fill more slowly but it will still fill to the right water level. If that doesn't work, consider a larger arrester or pressure reducing valves.
Question: Does one expansion tank, centrally located in a residential plumbing system, serve the same purpose as multiple water hammer arresters placed at the points of use? Answer: No, it absolutely does not—neither practically, nor under UPC-97 or IPC -97.
How long will a Water Pressure Reducing Valve last? The life expectancy of a water pressure regulator is most commonly in the range of 10 to 15 years. However, you may see a regulator malfunction at three years and one still properly functioning at 20 years old if regularly maintained.
What Happens When a PRV Fails? If a PRV fails and the water pressure in your home gets too high, it can cause a range of problems. These problems can include: Leaking appliances: High water pressure can cause appliances like washing machines and dishwashers to leak or fail prematurely.
A faulty toilet fill valve that doesn't close completely or a quick-closing fill valve are both possible causes of water hammer that occurs after you flush a toilet.
Water hammer is usually caused in high pressure (e.g. mains pressure) water systems either when a tap is turned off quickly, or by fast-acting solenoid valves, which suddenly stop the water moving through the pipes and sets up a shock wave through the water, causing the pipes to vibrate and 'shudder'.
A common cause of water hammer is high water pressure. If your pressure is running near 100 psi, then it's likely the cause of your issue. Normal pressure should be approximately 30 to 55 psi. To solve this problem, consider installing a water pressure regulator.
If you're hearing banging noises at random, even while no water is running, it's likely that there's some sediment buildup at the bottom of your water heater. If this is the case, what you're hearing is the resulting reverberations of steam bubbles coming out of that built-up sediment.
Mitigating Water Hammer Damage
Slowing down the flow variations in the network. Surge tanks with throttling (water column) Air chambers with throttling orifice. Quick-opening/slow-closing valves.
The extreme pressure caused by water hammer can blow out gaskets and cause pipes to suddenly rupture, causing serious injury to anyone nearby.
Left untreated, water hammer can lead to actual damage to pipework, appliances and components of any system. Over time this damage can accumulate and result in the premature failure of parts of the plumbing system and all the watery hassle that can cause.
Water arrestors by their design are an addition to the pipe. A little air chamber that extends perpendicular off each that is sealed off from water. When the water moves suddenly in the pipe that air chamber absorbs the shock. As they get used though, over time they wear out making them ineffective.
Surge (Water Hammer)
Without question, the primary cause of water hammer in process applications is the quick closing valve, whether manual or automatic. A valve closing in 1.5 sec. or less depending upon valve size and system conditions, causes an abrupt stoppage of flow.
“Any spring-loaded, poppet-style check valve is going to prevent water hammer because they close before reverse flow begins.
Without mitigation from the proper kind of valve or pipe closure, water hammer can cause equipment damage and pose safety concerns in industrial settings. It can also cause leaks in the home and damage to residential appliances and property, especially if it goes untreated for a significant amount of time.