And that has absolutely nothing to do with expansion tanks. Water heaters explode due to a
combination of runaway heating *and* a failed temperature-pressure relief valve. If *that*
happens, no expansion tank is going to contain the enormous increase in pressure that
precedes a catastrophic steam explosion.
Water heaters explode due to the fact that water EXPANDS when heated.
(though some explode due to gas leaks) If you reread my post, you'll
see that I didn't claim that they explode due to check valves installed
You'll note that the following paragraph expanded on this to indicate
why you want to avoid "above nominal" pressures:
Regardless, you don't want to subject the various appliances in your home
(water closets, dishwasher, washing machine, dryer, etc.) to elevated
pressures -- possibly ABOVE their design limits!
regardless of whether or not the water heater will "explode".
OTOH, lack of an expansion tank *will* cause the pressure in the
system to rise to levels well above "nominal" -- unless the occupants'
usage patterns are frequent enough that pressure "vents" due to the
normal opening of fixtures around the house. As such, when tanks corrode,
over time, the increased pressure is more likely to force a leak and/or
catastrophic failure of the tank -- before the TPR engages.
False. Water heaters explode due to the fact that water expands by several orders of
magnitude when it is BOILED. Simple thermal expansion of water due to heating in normal
operation does not cause water heaters to explode.
And I didn't say that you did make that claim.
True enough -- but lack of an expansion tank WILL NOT cause a water heater to explode.
If the thermostat on a water heater is functioning properly and the
water heater is not on the top of a high mountain (or in an airplane)
it is almost impossible for water to boil in the water heater, with
maximum high limit temperatures for domestic water heaters in north
america well below 190F or 90-ish C.
Years ago, many "boilers" had no thermostat or only rudimentary
thermostats and a good friend of min's family home "blew up" one
sunday morning when the rivetted copper water heater tank let go. Toot
the floorboors off the joints on the main floor and upstairs except
where the beds were located, took out all windows and doors, and
unseated the roof. It was aver a month untill the farmhouse was
habitable again and neighbors iver a mile away heard and felt the
bang. Fortunately no-one was injured although their ears rang for a
while. (and nobody fell through the floor getting out of bed!!
On Sat, 21 Nov 2015 17:55:45 -0000 (UTC), Doug Miller
For the record, I'm not talking about the pressure valve. I can see
that that's a good thing, and the house was built with one, which
hasn't required a bit of maintenance in 36 years.
But what's wrong with my water going into the city supply. It's the
same water they gave me in the first place. If it was good enough
for me, why isn't it good enough for them again? Do they think I
squeezed into the pipes and poisoned it?
And even if it does back up, is it going to back up all the way
through my basement, under the front yard to the water main? Seems
to me it will back up no more than 20 feet, and when I use the water
again, the backed up water will come back into my own house.
On Saturday, November 21, 2015 at 2:08:07 PM UTC-5, Micky wrote:
the reason for anti backflow prevention.....
lets say you have a garden hose filling your swimming pool. the main fails and the input pressure is now zero.
your icky pool water now siphons into the main all the way to your neighbors, they drink it and can get very ill
Water was off one day for 3 hours working on line own street. Told us to
open big sink cold water spigots to clear the air out of the lines. The
water was nasty brown. I guess that normal for old lines.
Over the years I had 6 houses custom built(5 in the city, 1 cabin;
county jurisdiction) I used to dialise at home with machine supplied and
installed by Alberta health care service until I had transplant. I heard
of back flow check valve and have them in the house, never heard of
expansion tank(not counting one with cabin well.) Nothing happened, two
hot water tanks in the house for past 45 years or so. We always had
pressure regulator set at 60 psi when water is running. Likewise out at
cabin. Is my house gonna blow up without expansion tank. I'll let you
know when it happens, LOL!
If city supplied water pressure is 120psi, that is insane IMO. House
plumbing should be done to deal with that kinda pressure using heavier
gauge piping or whatever....
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