On Sep 9, 5:07*am, "Robert11" wrote:
Hello,

Have the typical Delta single-handle faucet for the kitchen sink.
At least 10 yrs old.

Has the single good size ball type of valve inside the handle.

Whenever we turn it ON, the hot or cold, there is a big "bang" in the pipes.

Am tempted to call it a water-hammer, but I always thought water hammer, in
the true sense of the word, was only when one closed a valve, and the
ensuing pressure wave due to the running water being shut, suddenly, caused
the hammer.

Is this true ?

We have no problem when shutting; only when turning it on.

Anyway, I replaced the small hot and cold top-hat rubber seals and their
springs.
No change. *Still happens.

But there is a built in water diverter valve that goes to a hose sprinkler
for cleaning pots and pans, I guess.
We never use the hose.

Think this valve might be actuating and causing the problem ?

Hard to see how, as the end of the hose is of course shut off, so even if
the valve actuates, it is leading to a "closed" section of hose. *But,....?

Any thoughts on this would be most appreciated.

Thanks,
Bob

When I re-did my 1930's house plumbing recently (PEX) I put in water
hammer arrestors in the laundry on the hot & cold water lines.

They are the piston style & installed inside the wall. I can hear
them activate when the fill valves turn on, not when the when they
turn off.
They are actually behaving as a water accumulator in an attempt to
maintain water pressure.......when the fill valve opens, the line
pressure drops & the arrestors supplies a bit of water.

You are correct that "real water hammer" occurs when the kinetic
energy of the a long run of water is dissipated as a pressure spike
when a valve is suddenly shutoff.
But if you've ever played with a garden hose or worked with high
pressure hydraulics.....you can see how hoses jump & whip as valves
are turned on AND off.

I believe that what oyu are experiencing is similar to what happens in
my laundry.

If you turn the water on slowly do oyu still get the noise? How long
is the piping run to the kitchen?

I dont think its the diverter valve.

You could try adding some of those small screw-on laundry arrestors to
see if they help.

The sudden pressure drop in the water lines could causing them to jump
around. Give the arrestors a try & secure any loose pipes.

cheers
Bob

PS....Mike rocks proposed experiment is a good one, let us know how it
works out.