Water Hammer ??

[raybush]

I think what i've got is a water hammer i think that is what it's called .
I've recently fitted an electric shower (cold water mains fed) and have a slight noise on a cold water pipe that is boxed in in the corner of my kitchen .
When the shower is turned off i get a noise from a cold water pipe that is boxed in and would be a pain to uncover ,it would entail removing floor and wall
units ,tiles etc etc .
All the plumbing in the house has been inherited ,but up until fitting the shower has been fairly good .I'm quite sure that the cold water pipe that i cannot get to is not clipped and could be the culprit .
Is there any gadget that can be fitted in the cold water supply ,which would remove this pressure that i presume is causing the pipe to make a noise.
I hope i've explained this so that some sense can be made of it.
I just want to get rid of this noise with less fuss.
Thanks

[tonyav]

Something like this maybe.
https://www.ebay.co.uk/itm/153554215798?chn=ps&norover=1&mkevt=1&mkrid=710-153316-527457-8&mkcid=2&itemid=153554215798&targetid=4585513249221171&device=c&mktype=&googleloc=&poi=&campaignid=398826050&mkgroupid=1310618119775374&rlsatarget=pla-4585513249221171&abcId=9300501&merchantid=87779&msclkid=994f0dcf275715832a086db461bc8afc

[bluemoon1]

When the shower is turned off?

[bluemoon1]

Is that at the shower or at the isolation tap?

[raybush]

Yes ,when the shower is turned off i get the noise on a C/W mains pipe away from where the shower is .
It sounds like the Arrester suggested may solve the problem, should it be fitted in the supply pipe up to the shower ??.
Thanks

[The Builder]

Tony's link is correct, Ray.

It doesn't need to be fitted in the shower riser, Ray. Anywhere on that particular branch is ideal.
Perhaps under the basin near the shower.

(It may well work if sited in the usual place which is under the kitchen sink.)

[Bazile]

We have that noise that is described .
Like someone knocking a pipe with something made of metal .

Heard when for example when the washing machine finishes taking in water or when a tap is turned off .

So , how is the pressure causing that knocking sound ?

[The Builder]

Baz... dishwashers/washing machines/etc.
They have a shut-off valve that abruptly turns off the water supply.
It's the sudden nature of the supply being cut off that sends a shock wave back through the whole system.

Turning off a tap slowly often doesn't result in this. Doing it quickly can. Also quarter-turn taps can do the same thing.

High water pressure doesn't help either. MOST properties have far too high a pressure than is really needed. (6,7,8 Bar or more. 3 Bar is usually enough.)

[Bazile]

Thanks TB

It's one of those things I've never thought to ask what causes it - it's just been there :-)

[raybush]

Thanks for the very helpful replies .I only said the shower as the supply pipe to it runs along the ceiling in the garage and has quite a good access or ,i could fit it in the loft where the supply to the shower is tee'd from.
Thanks again

[The Builder]

Either would be fine, Ray. No difference at all. Choose whichever is easier.