On 21/11/2012 11:09, JakeD wrote:
Phil K wrote in :

I wondered about that. Has anyone else here found that to make a
significant improvement? It would be good if someone made a special
vibration-dampening pipe for this purpose.

I'm looking at the copper pipes coming from my boiler, and am thinking
about embedding them in concrete to subdue the sound waves in the pipes.

You don't want concrete apart from causing corrosion that will just
couple the noise into the brick structure of the house!

You can cast a reasonable bell out of concrete if you try hard enough
(or make springs out of it).

Something like a HDPE foam sleeve tie wrapped onto the pipes or
sorbothane might damp out some of the noise. My CH pump is supported
this way. You might need to experiment to find the right separation of
supports to damp out the worst resonance(s) in the pipework.

A noisy new install boiler is most likely air in the system somewhere
allowing it to kettle. When everything is off bleeding the system at the
highest point ought to fix it after a couple of goes.

Sound transmission is astonishingly difficult to prevent. The dense rock
wool sold for cavity wall insulation works fairly well as an acoustic
damper that is not flammable and has reasonable acoustic mass.

--
Regards,
Martin Brown