noisey pipes

[angefoh]

OK I have installed a 28mm copper inlet cold water pipe to feed my upstairs bathroom. It reduces to 22, then to 15mm to service shower, bath and toilet. The trouble is that when ever anyone uses any item upstairs water can be heard running through the pipes throughout the house. I have tried insulation to no avail. I have a PRV on the 28mm to reduce pressure to 3.5 bar. Again no change in noise level.
Any suggestions please.

 

[OffshoreGas]

If it’s the rushing sound of water it may actually be the taps making noise and not the pipes. Liquids transmit sounds quite will generally.

 

[ShaunCorbs]

I’ve had a few prvs that make a lot of noise due to there fuction

 

[OffshoreGas]

I’ve had a few prvs that make a lot of noise due to there fuction

And partially shut isolating valves.

 

[angefoh]

Unfortunately this noise is I think caused by the water passing through the 28 mm feed pipe and then finally being reduced to 15mm. I should I think in hind sight have reduced the pipe much sooner in the basement instead of running it all the way up to the bathroom before reducing.
The noise for want of a better description is like the sound of an old toilet cistern valve.
[automerge]1570527071[/automerge]

If it’s the rushing sound of water it may actually be the taps making noise and not the pipes. Liquids transmit sounds quite will generally.

Well yes but the noise travels through out the house. I have no noise from the hot water (15mm) feed. Just the cold water which I think in hind sight I should have reduced asap in the basement and just run 15mm or maybe 18 mm to the bathroom Would have saved money as well.

 

[Stigster]

The main causes of water flow noise are high velocity and uneven surfaces inside pipe or fittings. Pipe should be deburred to reduce turbulence, fittings and changes of direction should be kept to a minimum too.

How is the performance at the outlets? Are you getting more flow and or pressure than you actually need? I don't believe you've done anything wrong in running a 28mm pipe to the bathroom and reducing down as that's good practice. 28mm might be a bit overkill but it's not a bad thing.

What is the dynamic pressure and flow rates like at the outlets?

Have you tried simply reducing the flow rate at the stopcock which will in turn reduce water velocity?

 

[angefoh]

The main causes of water flow noise are high velocity and uneven surfaces inside pipe or fittings. Pipe should be deburred to reduce turbulence, fittings and changes of direction should be kept to a minimum too.

How is the performance at the outlets? Are you getting more flow and or pressure than you actually need? I don't believe you've done anything wrong in running a 28mm pipe to the bathroom and reducing down as that's good practice. 28mm might be a bit overkill but it's not a bad thing.

What is the dynamic pressure and flow rates like at the outlets?

Have you tried simply reducing the flow rate at the stopcock which will in turn reduce water velocity?

The water flow rate is good I have no way of checking dynamic pressure. On a friends advice I tried chocking(as he called it) the main valve (a leaver type ball valve ) and this just increased the noise, certainly at the valve it's self.

 

[Stigster]

A lever ball valve is not a good way to reduce water flow rate/velocity and "throttling down" or chocking as your friend calls it will certainly introduce more noise via turbulence to the system (as you've discovered). A proper good old fashioned stopcock is adjustable without introducing the noise like ball valves do.

A full bore lever valve is a great thing for reducing obstruction and therefore increasing flow rates but that seems to be the opposite of what you want in your situation.

I would change the full bore lever valve for a stopcock and have a play with that. You can close it down and test performance at your outlets and only have it open as far as you need for adequate performance at point of use.
[automerge]1570529395[/automerge]
Just to add, you can keep your lever ball valve and use it as an isolator and cut in a stopcock after it, or you can replace the lever ball valve with a stopcock entirely. Either way will give you better control.

 

[angefoh]

A lever ball valve is not a good way to reduce water flow rate/velocity and "throttling down" or chocking as your friend calls it will certainly introduce more noise via turbulence to the system (as you've discovered). A proper good old fashioned stopcock is adjustable without introducing the noise like ball valves do.

A full bore lever valve is a great thing for reducing obstruction and therefore increasing flow rates but that seems to be the opposite of what you want in your situation.

I would change the full bore lever valve for a stopcock and have a play with that. You can close it down and test performance at your outlets and only have it open as far as you need for adequate performance at point of use.
[automerge]1570529395[/automerge]
Just to add, you can keep your lever ball valve and use it as an isolator and cut in a stopcock after it, or you can replace the lever ball valve with a stopcock entirely. Either way will give you better control.

OK thanks, I was very lazy regarding de burring pipes and there are quite a few direction changes once the pipe becomes 15mm. So I may have shot myself in the foot so to speak. But I will try the stopcock method. I have nothing to lose.

 

[Stigster]

That's it, slow that water down to a level where the performance is adequate for your needs and you may well find a happy balance between system performance and noise generation.

Please report back to us with your findings and also please come back if you have any further questions regarding installation.

 

[angefoh]

That's it, slow that water down to a level where the performance is adequate for your needs and you may well find a happy balance between system performance and noise generation.

Please report back to us with your findings and also please come back if you have any further questions regarding installation.

OK I shall take a while before I acquire the bits and do the install. May I thank you for your input so far. best regards

 

[Stigster]

...