Squealing pipes at a weird time!!!

[MasterPlumbersKeymaster]

We have a home that is four years old. Since we purchased it, the pipes would make a high-pitched squeal when we turned on the cold water in the master bath. The builder at the time said it was because of a “burr” in the pipe and since it only happened once or twice a day, we ignored it.

NOW, however, we have a high-pitched squeal whenever we turn on the cold water water at any sink WHILE AT THE SAME TIME any toilet is being filled after a flush (washing hands after using toilet). This started occuring recently after we had to remove and replace a toilet due to some floor work in a bathroom. The squeal also occurs when we fill the washing machine with cold water.

We turned off the water to the house and opened all the faucets/flushed the toilets to get all the air out (and some came out), but this did not help.

Any suggestions? This is driving us crazy? What can we do, if anything?

[SylvanLMPParticipant]

Sounds like a velocity problem do to poor design.

Try to get your main water pressure and the incoming pipe size and ILL tell you your FPS of water.

Anything over 8 FPS should be avoided hot water 5 FPS

[GuestParticipant]

Thanks for your help. I do not have the FPS or the pipe size (1 inch I think though). However, I believe you are correct in your diagnosis. I went downstairs and turned the main valve to our house down (almost to closed) and the squeals have subsided. I also had to turn the flow into one toilet down. The water pressure to the faucets and tubs seem to be about the same so it evidently did not slow the water down too much by turning the flow into the house down.

I have to ask you . . . is there a way to correct the problem without turning down the flow to the house from the main line? A new valve or something that lowers flow?

I really appreciate your help.

Thanks

[SylvanLMPParticipant]

quote:

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Originally posted by David Logue:
Thanks for your help. I do not have the FPS or the pipe size (1 inch I think though). However, I believe you are correct in your diagnosis. I went downstairs and turned the main valve to our house down (almost to closed) and the squeals have subsided. I also had to turn the flow into one toilet down. The water pressure to the faucets and tubs seem to be about the same so it evidently did not slow the water down too much by turning the flow into the house down.

I have to ask you . . . is there a way to correct the problem without turning down the flow to the house from the main line? A new valve or something that lowers flow?

I really appreciate your help.

Thanks

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No problem David, OK lets assume it is too much velocity then you can do the following.

Under most sinks there is either an angle valve or a straight valve which if properly specified was a globe type which is designed for throttling unlike a gate valve (normally found on the main)

All you have to do is close each of these valves slightly until the noise stops.

As for one inch pipe lets say you have 60 PSI in coming pressure your velocity would be around 27 FPS If everything is flowing full blast and we are not taking friction losses into consideration.

Your “Flow rate” is about 67.5 GPM

So we can figure the installing contractor may have slightly miscalculated the incoming pressure and here is where the globe valves do their job of fine tuning the system so as not to cause excessive noise or erosion of the piping system.

One more point turning down a valve does NOT decrease the pressure per say as pressure remains constant BUT you do decrease the volume as your making the passage way smaller more resistence like a voltage drop in electricity when you have brown outs.

You are causing pressure drop ONLY because you are adding more restriction BUT if you put a gauge on this partically closed valve with a no running condition you would see the pressure remains the same.

Have a GREAT WEEK END

[GuestParticipant]

Sounds like the washer inside the inlet of the loo is vibrating and causing it to “squeal”. If the washer is made of a too soft a material or the pressure is too high, it bounces at high speed like a tuning fork.

[Author]

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