Caleffi 525040 1/2" Mechanical Shock Arrestor Prevents Plumbing Water Hammer

Excellent product does what it states on the box

Took approx 30 mins to fit, and now we are free of the pipe knock. The Caleffi Anti Shock device is well made, has a bit weight to it, and feels solid. I was concerned about the weight causing problems with the pipework, but when all was tightened up it was OK. Our pipe knock started after we had a new toilet fitted by a professional plumber (wish I did it myself and saved some money as he obviously did not take precautions of fastening the pipework down correctly before they were buried beneath dry-board). Now all is silent as it was before. I could not fit it directly to the toilet supply line due to space restrictions, so I fitted it below the sink which is approx 3 to 4 feet away, on the far side of the supply pipe from the toilet. It has just been fitted and like I have said is working great, but if in the future it starts to knock again I will update.

We had serious hammer in the pipe to our header tank even though we have a 4 bar pressure limiting valve. On bad days it could last for several minutes before ending, unless a tap was opened. I fitted a suppressor next to the tank in the shape of a dome which could be pressurised with a bicycle pump. It killed the hammer completely while filled with air, but the air tended to be absorbed after a month or two, so it needed regular re-pressurising. This device instead uses a sprung piston to dampen the hammer. The result is that it does not kill it instantly, but often there is a "groan" which lasts about 10 seconds as the spring does its work. But it needs no maintenance and after more than a year is still working effectively.

helped to reduce the water hammer greatly ,very good product now to see how it does over time,

Excellent product and service

stopped the banging pipes

Bought this for water hammer it did work at the beginning but now it no longer works we still have water hammer

Easy to fit but did not completely stop water hammer.