Expansion Tank Corrosion

[UWash]

Just want to share an experience I had so it doesn't happen to anyone else.

Arrived at my wash and had water pouring all over, it was spraying at the ceiling and cascading across the ceiling and down the walls.

The cause was a broken expansion tank, the tank corroded at the threads where the threads join the copper pipe fitting (Female adapter) and the tank broke right off. Full 1" line pressure of hot water was spraying for about 6 hours or so, best I can figure about 12,000 gal of water.

There was no dielectric fitting adapter between the dis-similar metals.

Everybody should check this, as it cost me a bundle because of water damaged controls on the boilers, computer PLC's and vending machine stock materials.

Has this happened to anyone else?????

 

[pitzerwm]

That's expensive and ugly. I use to have moisture detectors tied into my alarm system.

 

[robtl]

Just want to share an experience I had so it doesn't happen to anyone else.

Arrived at my wash and had water pouring all over, it was spraying at the ceiling and cascading across the ceiling and down the walls.

The cause was a broken expansion tank, the tank corroded at the threads where the threads join the copper pipe fitting (Female adapter) and the tank broke right off. Full 1" line pressure of hot water was spraying for about 6 hours or so, best I can figure about 12,000 gal of water.

There was no dielectric fitting adapter between the dis-similar metals.

Everybody should check this, as it cost me a bundle because of water damaged controls on the boilers, computer PLC's and vending machine stock materials.

Has this happened to anyone else?????

We had two iba with two different exp tanks like this and they were installed in a female adapter like your describing they both went bad by leaking but not breaking completely off. we went thru two on one machine before I installed a brass ball valve under them which seemed to stop the electrolysis (spelling) from happening...I know it is against boiler code to valve off a exp. tank. But by adding the BRASS valve it seams to stop the corrosion with the two dissimilar metals (brass and steel) verses (copper and steel)
also it lets you replace a bad tank without shutting down the whole system

 

[mjwalsh]

Wow that has got to be a wake up call for expert inspection....best done in house. I know it is easier said than done.

About a year ago, we had replaced a Watts Filltrol expansion tank with a brand new one ----still too much pressure on the boiler side. Replaced it with another brand new thinking defective-----same thing happened --- too much pressure. We tried another new one. We ordered online from Omega 3 pressure switches that we put in 3 ports that used to be for unreliable low water cutoffs to protect our boilers & shut all inlet water coming in to the system that would maintain any refill needs of our 3 small non steam hydropulse boilers. We notice now a year later the fill valve is working properly now ---- it must have been the Filltrol expansion tanks were on the shelf too long & were sticking.

From our experience dialectric unions do not work that well --- the best is to keep the boiler from having fresh oxygenated water depending on the type of boiler.

 

[Earl Weiss]

We had two iba with two different exp tanks like this and they were installed in a female adapter like your describing they both went bad by leaking but not breaking completely off. we went thru two on one machine before I installed a brass ball valve under them which seemed to stop the electrolysis (spelling) from happening...I know it is against boiler code to valve off a exp. tank. But by adding the BRASS valve it seams to stop the corrosion with the two dissimilar metals (brass and steel) verses (copper and steel)
also it lets you replace a bad tank without shutting down the whole system

You could simply install some brass fittings instead of the valve. I.E. a brass coupling.

 

[washnvac]

Get some simple water detection alarm triggers and wire them to an autodialer. At least you will know a lot quicker.