cold water pipes banging when turned off

steveo3002

our cold water pipes have started banging rather loudly when the cold tap is turned off

4 days ago i fitted new bathroom taps and all was well , but yesterday the water was off due to roadworks

not sure if its related to either of those

whats the fix for it

tomstickland

Water hammer I believe.
http://en.wikipedia.org/wiki/Water_hammer

andrew-b

Yes it sounds like water hammer as Tom said. Is the cold supply to the tap mains pressure?

Yesterday i replaced the old ball valve in the cold tank in the loft with a torbeck float valve (2nd hand one given to me by my Dad) and this morning i heard about 4or 5 pipe bangs when the torbeck shut off after refilling (having flushed toilet). I phoned Opella (torbeck manufacturer) and they are sending me some parts free of charge for the torbeck valve that are supposed to help suppress the water hammer. I suggest contacting the manufacturer of your new taps too and see what they say.

For now i've turned down the mains stop c*ck nearest the cold water tank in the loft and it's reduced the problem. Again you could do the same and turn down mains stop c*ck or any isolating valves near to your new taps.

Hope that helps

Andy

ormus

workmen outside seem to be the likely cause in your case.
turning your stop co ck down will help.
or fit a service valve to the main supply to do the same.
you can also buy a fixed pressure reducing valve (PRV). fit as above.
you will need to state what pressure you want, (ie if you have a combi boiler).
some PRVs are adjustable.

http://www.plumbingpages.com/featurepages/HWPRV.cfm

Canucklehead

andrew-b wrote: »

Yesterday i replaced the old ball valve in the cold tank in the loft with a torbeck float valve (2nd hand one given to me by my Dad)

Good evening: You need a valve which complies with BS1212-2 and Water Regulations ( i.e. Part 2 valve as recommended by EliteHeat in your thread). A Torbek is designed and approved for use as a toilet cistern valve not for a cold water storage cistern.
Best advice....do it right the first time and save yourself some longterm aggro. Don't be a bodger.
Apologies to the OP.;)

HTH

Canucklehead

andrew-b

Actually if you look at that thread you will see the torbeck i used is WRAS Approved (listing number 0803055) "manufactured in accordance with BS1212 Part 4" . From my understanding part 4 goes beyond the requirements of part 2 - though no one answered that on that thread where i asked it. I did actually ask Opella about the suitability for storage tank BEFORE i fitted it and they said it was suitable.

Although i mention the torbeck was second hand it was actually fairly new but a heavy-handed registered plumber fitting it snapped one of the pieces of plastic holding the arm on. As the plumber couldn't be bothered repairing it we obtained replacement parts from the manufacturer and reused it in my tank. But of course the plumber wasn't your OH so he must have been a bodger right :rolleyes:? I would normally buy new but as i knew where it had come from and it's history the torbeck got to live another life.

As for the water hammer effect that i now have, i have researched elsewhere and found mentions of other people using a torbeck valve in the storage tank in the loft that got water hammer and it was fixed by Opella supplying the same parts as they are sending me which make the valve less sensitive.

So before you go around offending people by wrongly calling them bodgers i suggest you get your facts straight first. I don't bodge things and take great pride in everything i do, never rush things and always research things very carefully first. Just because i don't have years of experience as a plumber and that i bought a house where "real" bodgers had previously been let loose doesn't make me a bodger too. I don't claim my DIY plumbing skills are perfect nor upto the perfection of your OH's :rolleyes:- but the way to learn is to actually try it!

Anyway what has accusing me of being a bodger got to do with the OP who I was actually trying to help - other than perhaps trying to run your small crusade of stopping homeowners carrying out plumbing work in their own homes!?

p.s. torbeck has a c in it... i thought you were a secondary school teacher??!!

Canucklehead

andrew-b wrote: »

Actually if you look at that thread you will see the torbeck i used is WRAS Approved (listing number 0803055) "manufactured in accordance with BS1212 Part 4" . From my understanding part 4 goes beyond the requirements of part 2 - though no one answered that on that thread where i asked it. I did actually ask Opella about the suitability for storage tank BEFORE i fitted it and they said it was suitable.

Although i mention the torbeck was second hand it was actually fairly new but a heavy-handed registered plumber fitting it snapped one of the pieces of plastic holding the arm on. As the plumber couldn't be bothered repairing it we obtained replacement parts from the manufacturer and reused it in my tank. But of course the plumber wasn't your OH so he must have been a bodger right :rolleyes:? I would normally buy new but as i knew where it had come from and it's history the torbeck got to live another life.

As for the water hammer effect that i now have, i have researched elsewhere and found mentions of other people using a torbeck valve in the storage tank in the loft that got water hammer and it was fixed by Opella supplying the same parts as they are sending me which make the valve less sensitive.

So before you go around offending people by wrongly calling them bodgers i suggest you get your facts straight first. I don't bodge things and take great pride in everything i do, never rush things and always research things very carefully first. Just because i don't have years of experience as a plumber and that i bought a house where "real" bodgers had previously been let loose doesn't make me a bodger too. I don't claim my DIY plumbing skills are perfect nor upto the perfection of your OH's :rolleyes:- but the way to learn is to actually try it!

Anyway what has accusing me of being a bodger got to do with the OP who I was actually trying to help - other than perhaps trying to run your small crusade of stopping homeowners carrying out plumbing work in their own homes!?

p.s. torbeck has a c in it... i thought you were a secondary school teacher??!!

Good morning: I'm suggesting you do the job right the first time, Andy and save yourself problems in the future.....as EliteHeat suggested Part 2 valve meets requirements...as for your personal comments????

Trades give advice on this forum to help DIYers such as yourself and will point out if the techniques proposed or used by DIYers are unsafe, not meeting building regulations or not moneysaving over the long term....in other words we encourage good practice...if someone takes offence then so be it;)

Good luck with your project. (Once again, my apologies to the OP....hope you've sorted your problem)

HTH

Canucklehead

EliteHeat

Blimey! all this over a valve, in the words of the inexplicable Ringo - peace and love, peace and love, no more letters etc

andrew-b

:whistle: :silenced:

moneysavingplumber

steveo3002 wrote: »

our cold water pipes have started banging rather loudly when the cold tap is turned off

4 days ago i fitted new bathroom taps and all was well , but yesterday the water was off due to roadworks

not sure if its related to either of those

whats the fix for it

Is this new tap a quarter turn tap on a mains/pressurised supply and is this the offending tap? If so it's likely it is having a 'concussive' effect, sometimes it can be noticed when the lever or tap handle springs back. My favoured remedy for all types of water hammer has always been to add a double-check valve followed by a small expansion vessel just downstream of the incoming mains stopcock, it's not hugely expensive to do.

I've found Torbecks don't consistently work on water hammer anyway, in reference to above discussion, (and I agree they are not suitable to be used in CWSTs) and even Pegler 'true' equilibrium ball valves have failed to cure the most severe cases I have come accross, but the above remedy has always worked and will work long-term provided the mini expansion vessel remains charged to the correct pressure.

andrew-b

Thought i'd just add to this thread to say that the parts sent to me via opella completely solved my water hammer problem introduced with the torbeck valve (didn't even have to remove it to fit). Basically they sent me a replacement for the part that the float arm clips onto, with an additional white plastic disc that sits inside it to create like a buffer zone.
For those interested the patent showing details is here: http://www.wipo.int/pctdb/en/fetch.jsp?SEARCH_IA=GB2002000876&DBSELECT=PCT&C=00&TOTAL=1&IDB=0&TYPE_FIELD=256&SERVER_TYPE=19-00&QUERY=GB02%2F00876&ELEMENT_SET=BASICHTML-ENG&START=1&SORT=41238260-KEY&RESULT=1&DISP=25&FORM=SEP-0%2FHITNUM%2CB-ENG%2CDP%2CMC%2CAN%2CPA%2CABSUM-ENG&IDOC=477919&IA=GB2002000876&LANG=ENG&DISPLAY=STATUS
..i was interested to know the theory behind it as it seemed such a simple solution. It appears the extra parts were specifically designed for plastic loft tanks with the same problem i had.


Andy