Noisy or "singing" pipes

[AMEdinburgh]

We have an increasing problem with noisy pipes when one of the upstairs loos is flushed. Was fine for best part of 10 yeas and no additions or changes. All copper with swept bends where possible and end fed copper.

Pipes all under carpeted floors so access not easy.

Loos have normal float valves with the inch and a bit corrugated washers

Not sure if incoming pressure higher.

Is there any easy fixes here?

Any helpful suggestions gratefully received. Thank you.

 

[Goldberg]

We have an increasing problem with noisy pipes when one of the upstairs loos is flushed.

Loos have normal float valves with the inch and a bit corrugated washers

Replace the rubber washer AND the plastic seat.

 

[AMEdinburgh]

Thank you for your suggestion

With something different? I think they make a high pressure and a low pressure cone and washer.

Neither leak at present.

 

[Goldberg]

With something different?

You need to fit the correct sat for your supply pressure.

I don't know if that's different to what you've got, because you haven't said what you've got.

I think they make a high pressure and a low pressure cone

Yes.

...and washer.

No.

Neither leak at present.

But one of them makes a noise.

 

[fingertight]

for what its worth Id change the the entire ball valve..a good torbeck valve is only around £15 and very quiet on refill...just make sure you check if the existing valve is side or bottom entry. If that fails you can buy "shock arresters" from plumb centre (nationwide) for around £20... they WILL stop any water hammer issue, as stated though, changing the valve should suffice

 

[Goldberg]

Another member of the Disposable Society strikes again - they seem to live by the ethos "why change two parts for £1 when you can spend £15 and increase the length of the job".

 

[AMEdinburgh]

Seems to be sorted with a pair of cones and washers, so thank you.

What makes the noise? The cones vibrating in their enclosure?

 

[Goldberg]

You're welcome.

The noise is pipe resonance, caused by the washer vibrating against the seat.

This happens when the washer-to-seat joint isn't good enough to shut off the water flow 'cleanly' - water passes through a small gap at a rapidly fluctuating rate. The flow rate fluctuates because the pressure oscillates (and vice versa). The pressure oscillates because the movement of the washer becomes SHM (simple harmonic motion), and remains so until the level of the water rises enough to dampen (no pun intended) the oscillation.

 

[AMEdinburgh]

Thank you again

 

[Goldspoon]

You're welcome.

The noise is pipe resonance, caused by the washer vibrating against the seat.

This happens when the washer-to-seat joint isn't good enough to shut off the water flow 'cleanly' - water passes through a small gap at a rapidly fluctuating rate. The flow rate fluctuates because the pressure oscillates (and vice versa). The pressure oscillates because the movement of the washer becomes SHM (simple harmonic motion), and remains so until the level of the water rises enough to dampen (no pun intended) the oscillation.

I'm going to memorise all of that - for when a customer next asks.

 

[Goldberg]

So, we meet at last, Mr Goldspoon.

 

[RigidRaider]

Believe it or not, badly adjusted bicycle rim brakes can vibrate and howl due to a phenomenon that's not too dissimilar.

 

[Nige F]

Does that mean it`s similar

 

[Nige F]

.

The noise is pipe resonance, caused by the washer vibrating against the seat.

This happens when the washer-to-seat joint isn't good enough to shut off the water flow 'cleanly' - water passes through a small gap at a rapidly fluctuating rate. The flow rate fluctuates because the pressure oscillates (and vice versa). The pressure oscillates because the movement of the washer becomes SHM (simple harmonic motion), and remains so until the level of the water rises enough to dampen (no pun intended) the oscillation.

Another gasfitter with a degree