The other faucets probably didn't show signs of being overpressured because
the aerators or built in flow limiters were working on those sinks which
apparently they were not in the kitchen sink

The expansion tank may or may not be needed. If you already have a few
water hammer arrestors and the hot pipe volume is not too great, you can get
by without. Think of the bladder (expansion tank) as a very large water
hammer arrestor installed at the supply end of the pipe instead of at the
delivery end. Both of these devices allow the water pressure to be absorbed
in a flexible component instead of stressing the otherwise rigid walls of
the pipe network.

If there is a check valve on the cold supply going into the hot tank (or the
new pressure regulator) such that when the hot water expands the additional
volume has no where to back out, then you will see a short shot of pressure
whan you turn on the tap and then quickly return to normal.








wrote in message
ups.com...
Okay, here you go:

The water coming out of my kitchen faucet blasts out like a fire hose.
No other faucet in the house seems to have this problem. Today, I had a
plumber over for a different problem, and asked him to render an
opinion on the faucet-pressure problem.

He looked into it (I wasn't home when he did his check; the wife had
him call me), and said the pressure regulator in between the street
service and the house wasn't actually regulating the pressure -- it was
letting in 145 pounds (psi?), which is street pressure. I raised the
question as to why the other faucets in the house weren't blasting; he
says he checked, and yeah, they are all overpressured (I just don't see
it -- or, rather, feel it).

The fix, apparently, is to replace the regulator (which would seem to
make sense), and also to put some kind of "bladder," or smaller tank,
on top of my water heater, so that when water is let into the tank at a
specific pressure, and then heated (raising the pressure), it won't
blow anything out.

It's this last part especially that sounds fishy. I've never heard of
it before, never seen a water heater that has such a device, and the
"physics" doesn't ring true to me.

So, what are the expert opinions on all this here? (My wife just phoned
again, and this guy wrote on his work order that we should "turn the
water off [that's the main water supply to the house]" so as not to
risk damaging anything.)

Oh, and if anyone has any ideas on the blasting faucet, I'd appreciate
hearing those, too.

Shane