Expansion Tank failures
I apologize in advance for “too-much-information”; but, this is conclusive.
Working with Mid-Shore Plumbing, the cause of
expansion tank failures has been verified.
The tanks have three major parts.
*The upper hemisphere
*The lower hemisphere
*The Rubber bladder
The upper and lower halves are separated by the expandable
bladder.
If not properly pressurized, the bladder stretches and
breaks allowing the water to fill the upper half.
The lower half interior is glass lined which prevents rust.
The upper half is unprotected steel which rusts when exposed to
water.
It is possible that many bladders have failed immediately after
installation.
Mid-shore Plumbing cut this tank in half to see what is
happening.
Even thought the tank has not rusted through and leaked, it has
failed
Photos.
Looking toward the lower half it can been seen that the black bladder is
torn.
The bladder is attached at the middle of the tank.
It is designed to keep the water below and expand if
necessary.
Note that the lower half shows no rust inside since it is glass lined to
prevent corrosion.
The upper half was exposed to water and is rusting.
It may take many months to finally leak.
This tank looked perfect from outside.
The welded seam is where the upper and lower halves are
joined.
The indent is where the bladder hoop is attached.
Bottom line: Even of properly installed,
replace every 4-5 years.
Make sure your installer pressurizes the tank to match the water pressure
in your unit.
Pressures vary from floor to floor,
(900 MC 4th floor was 45 PSIG.)( 700 CC, 2nd floor, 55
PSIG.)
A simple check to see if your bladder is
broken:
Unscrew the blue cap on top of the tank.
Push the air valve button quickly.
If water squirts out , the bladder has definitely failed.
Mid-Shore Plumbing:
206 Market
Square
Cambridge, MD 21613
410-228-9003
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