# pipes banging



## Tech Dawg (Dec 13, 2010)

Hey, I have a customer that I finished a tub to shower conversion at the end of January.... time goes by and last weekend I get an email about a couple small defects in an obscure shower shower... totally pointless but the supply house ordered a new one for replacement.
This morning I get an email that when the valves close (shower and sink) that there is a banging vibration at the shower valve and washer/dryer... I took out a 3 handle tub faucet and added a single handle shower but I did not touch any other pipng. He said that I need to strap all his pipes. Seems like this guy sits around on the weekends and tries to find something wrong. I'm assuming that the banging is coming from a pressure issue or something... what do you guys think??? Need a little advice on this one, this was not happening weeks ago when I finished this job.....


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## Tech Dawg (Dec 13, 2010)

Additional info:

1/2" copper
City water feed
Wolverine Brass valve (iv only ever had this problem with the Moentrol valve)
House also has a hot water baseboard heat system


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## rex (Jul 2, 2007)

has your plumber been there to look at the problem yet??


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## Tech Dawg (Dec 13, 2010)

I installed the fixture...
The company that I used to work for would send us back and have us add an arrestor and call it a day. Since I've been on my own I have not had this problem and wanting to know the actual science behind it


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## Tinstaafl (Jan 6, 2008)

Tech Dawg said:


> The company that I used to work for would send us back and have us add an arrestor and call it a day.


That's usually the more practical solution.

Piping systems are often designed with one or more air pockets to absorb the inertia from moving water when it's suddenly stopped by turning off a valve. Over the years, that air can slowly get absorbed into the water until there's none left, and you start getting the hammering effect.

You can drain the entire system to restore the air to those pockets, but that can take a long time--and still not be effective without forcing air through the pipes to push out any "pools".

Quite likely you did nothing to create the problem; it was already there and consciously or unconsciously, the HO expected your new work to eliminate it.


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## Tech Dawg (Dec 13, 2010)

Great info, the homeowner wants me to strap pipes... and make this my problem. How would you respond to this? Is an arrestor a worthwhile solution to show that I did something? I will be going back to replace a shower door and they are trying to make the pipe problem mine since I touched it last... I was gonna tell them that "I'm not a RexPert Plumber". LOL


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## Tinstaafl (Jan 6, 2008)

First thing is to verify that the problem actually exists in the way you're understanding his email. You might turn the valve off like a normal person, but he's "slamming" it closed.

Tough call on which way to handle it. We all want to finish up with the customer thinking we walk on water, but it sounds like that ain't gonna happen with this guy. I'd probably go ahead and put an arrestor in, and eat it for PR's sake. But only AFTER explaining why it's not your fault and what a good guy you're being. Maybe do a token strap or two.

If that doesn't take care of it, explain that the problem is out of the scope of your normal work, and he needs to call Rex.


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## KillerToiletSpider (May 27, 2007)

It's water hammer, caused by a quick acting valve and a lack of air chambers. My guess is you replaced an older style compression type facet with a pressure balancing valve that acts as a quick closing valve, which creates a hammer affect from the sudden stop of flow. If there are air chambers installed then it may be a case of the system being water logged, you would need to provide that information.


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## Tech Dawg (Dec 13, 2010)

I took out a 3-handle and installed a WB single handle shower faucet


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## KillerToiletSpider (May 27, 2007)

Tech Dawg said:


> I took out a 3-handle and installed a WB single handle shower faucet



Were there air chamber installed?


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## Tech Dawg (Dec 13, 2010)

No, in a year of business on my own I have not installed air chambers, I usually cut out old valve and adapt to existing pipes...
Prior to being on my own I worked for a tubliner company for 10 years and averaged 4 shower valve installs per week and had this problem maybe 2 or 3 times but like I said, they would just make me go back and install an arrestor


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## KillerToiletSpider (May 27, 2007)

Tech Dawg said:


> No, in a year of business on my own I have not installed air chambers, I usually cut out old valve and adapt to existing pipes...
> Prior to being on my own I worked for a tubliner company for 10 years and averaged 4 shower valve installs per week and had this problem maybe 2 or 3 times but like I said, they would just make me go back and install an arrestor


Well, your installation is the cause of the problem, so it is on you to fix it.

Try shutting off the water to the house and opening every faucet, allowing the entire system to drain, and then re-fill it slowly, there is a small chance this will alleviate the problem.


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## rex (Jul 2, 2007)

Tech Dawg said:


> I was gonna tell them that "I'm not a RexPert Plumber". LOL





Tinstaafl said:


> If that doesn't take care of it, explain that the problem is out of the scope of your normal work, and he needs to call Rex.


 
thats right dont ever forget it when your in over your head :laughing:


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## Tech Dawg (Dec 13, 2010)

Thanks guys, ill getr fixed.... hey, sh*t happens


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## Mike's Plumbing (Jul 19, 2010)

Boy, you can sure tell who does service work here.

#1, you don't heed an air chamber. That was for back in the old days when the mixer valves were designed and build different so that advice is false.

#2, the newer style pressure balance mixing valves are not "quick closing", that's simply unfounded advice.

In engineering when they talk about quick closing valves they are referring to solenoid valves like on a dish washer or a washing machine.

Anyhow, based on experience the odds are the cartridge has debris in it from shutting the water off, working on it, and turning it back on. Take it out and blow air in the cartridge or put a new cartridge in.

This is not a new problem and is something that, in the repair business at least, is common and the solution is 99% of what I explained.

Mike


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## KillerToiletSpider (May 27, 2007)

A 1/4 turn valve is a quick closing valve, it can be actuated just as fast as a solenoid controlled valve, as can any single handle T/S valve. Because of this air chambers are needed MORE today than they were 40 years ago when most valves were compression style valves that were slow closing valves by the design. That is why many states now require mechanical arrestors be installed for every bathroom group, whereas the code I follow requires air chambers at every single outlet, excluding hose bibbs, even though a W/C is technically a slow closing valve.

I have done service calls in homes that were thirty years old and started developing hammer problems, and draining the system and restoring the air to the system fixed the problem.

Perhaps it is not as noticeable with the hose like PEX piping, but with copper piping it is noticeable.


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## Mike's Plumbing (Jul 19, 2010)

No, that's simply untrue and unfounded. 

Clean the cartridge and let me know what happens. 

Mike


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## MALCO.New.York (Feb 27, 2008)

Do not be alarmed because your "pipes are banging". It is natural at that age. They are just trying to make little pipes!


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## KillerToiletSpider (May 27, 2007)

Mike's Plumbing said:


> No, that's simply untrue and unfounded.
> 
> Clean the cartridge and let me know what happens.
> 
> Mike


The only person posting anything unfounded is you.

Or are you going to tell me that they make mechanical hammer arrestors and codes require them for no reason whatsoever, and that the whole thing is a scam to turn a profit for the manufacturers?


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## The Coastal Craftsman (Jun 29, 2009)

KillerToiletSpider said:


> The only person posting anything unfounded is you.
> 
> Or are you going to tell me that they make mechanical hammer arrestors and codes require them for no reason whatsoever, and that the whole thing is a scam to turn a profit for the manufacturers?


I would take a guess but I think mike is joking around. I have lost count of how many times I have had water hammer show up after fitting a qtr turn valve after customer has had a compression valve for so long. The best fix was to tell them to slow down when closing the valve. Many would just flick them shut and it would be almost instant close.


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