My expansion tank rust out in about 1 year.replaced 3 in about 4 years.I've been told its high oxygen in the water .How can I get rid of it.

you won't get it all out because if you do and there isn't anywhere for
the expansion, then the water will burst the pipes if it gets to cold.

Empress2454 #124457


The best Games


a href=http://www.gamestotal.com/Multiplayer Online Games/a a
href=http://www.gamestotal.com/Strategy Games/abra
href=http://uc.gamestotal.com/Unification Wars/a - a
href=http://uc.gamestotal.com/Massive Multiplayer Online
Games/abra href=http://gc.gamestotal.com/Galactic Conquest/a -
a href=http://gc.gamestotal.com/Strategy Games/abra
href=http://www.stephenyong.com/runescape.htmRunescape/abra
href=http://www.stephenyong.com/kingsofchaos.htmKings of chaos/abr



BOB1901 wrote:
My expansion tank rust out in about 1 year.replaced 3 in about 4
years.I've been told its high oxygen in the water .How can I get rid of
it.




--
BOB1901

wrote in message
ups.com...
you won't get it all out because if you do and there isn't anywhere for
the expansion, then the water will burst the pipes if it gets to cold.

Empress2454 #124457

Oxygen in water is different than air in the system. It does not affect
expansion or freezing of pipes.

High oxygen does cause corrosion. In industrial systems, the best way to
get rid of it is to use sulfites as an oxygen scavenger and heating the
water in a pre-heat tank to at least 190 degrees or in a deaerator where
the water is heated under pressure to about 220 degrees to drive off oxygen.

Edwin Pawlowski wrote:
wrote in message
ups.com...
you won't get it all out because if you do and there isn't anywhere for
the expansion, then the water will burst the pipes if it gets to cold.

Empress2454 #124457

Oxygen in water is different than air in the system. It does not affect
expansion or freezing of pipes.

High oxygen does cause corrosion. In industrial systems, the best way to
get rid of it is to use sulfites as an oxygen scavenger and heating the
water in a pre-heat tank to at least 190 degrees or in a deaerator where
the water is heated under pressure to about 220 degrees to drive off oxygen.

To the o/p...
Use automotive coolant (antifreeze) in the system?

Mark

"BOB1901" wrote in message
...

My expansion tank rust out in about 1 year.replaced 3 in about 4
years.I've been told its high oxygen in the water .How can I get rid of
it.


Is the system open or closed?

It sounds to me like it's an open one and uses a expansion tank designed for
a closed system.

This is a radiant floor heating system. The sys has an air eliminator,operating pressure is around 15-20 lbs,temp is about 130 degrees and closed sys.The sys uses a hot water tank to heat the water. I had tried anti freeze to act as a lubricant to stop the rusting of the expansion tank (mixed a few gallons in to the sys),no luck. It seemed to make the expansion tanks rust faster.First tank lasted about 18 months,second about 12 months ,third about 9 months. Any way of reducing the oxygen in the water.

Edwin Pawlowski wrote:

wrote:

you won't get it all out because if you do and there isn't anywhere for
the expansion, then the water will burst the pipes if it gets to cold.

The expansion tank is for warmer water, no?

High oxygen does cause corrosion. In industrial systems, the best way to
get rid of it is to use sulfites as an oxygen scavenger...

Would this remove all the oxygen in the expansion tank? Seems unlikely.
Would pressurizing the expansion tank with nitrogen make it last longer?

Nick

wrote:
Edwin Pawlowski wrote:


wrote:



you won't get it all out because if you do and there isn't anywhere for
the expansion, then the water will burst the pipes if it gets to cold.


The expansion tank is for warmer water, no?


High oxygen does cause corrosion. In industrial systems, the best way to
get rid of it is to use sulfites as an oxygen scavenger...


Would this remove all the oxygen in the expansion tank? Seems unlikely.
Would pressurizing the expansion tank with nitrogen make it last longer?

Nick


The expansion tank allows for the expansion/contraction of water as it
heats and cools.

Dry nitrogen in the expansion tank will help with rusting on the AIR
side of the tank.

Oxygen dissolved in the water will eventually create bubbles in the
system that will have to be bled off,else the pumps won't work. Filling
a radiant loop with RO filtered water gets you VERY squeeky clean
water,but comes at a price of excess dissolved oxygen. If you can afford
it, then Distilled water is a better choice as there is no excess oxygen
generated in the production of distilled water. IMHO, Distilled water
or RO water are the only water sources that SHOULD be used to charge/top
off a radiant heat system.

BOB1901 wrote:
....

This is a radiant floor heating system. The sys has an air
eliminator,operating pressure is around 15-20 lbs,temp is about 130
degrees and closed sys.The sys uses a hot water tank to heat the water.
I had tried anti freeze to act as a lubricant to stop the rusting of the
expansion tank (mixed a few gallons in to the sys),no luck. It seemed to
make the expansion tanks rust faster.First tank lasted about 18
months,second about 12 months ,third about 9 months. Any way of
reducing the oxygen in the water.

What does the installer say? Surely yours isn't the only one they've
done. What is unique about yours? If everybody has the same system,
they all should have similar problems. Failing help from the local
installer, have you contacted the system manufacturer for advice?
There are lots of radiant floor heating systems in use and I've not
heard of this being a generic problem so _something_ must be unique
here.

I've no direct experience w/ one of these systems, but I'm puzzled as
to how you're getting such high dissolved O2 to begin with. Is the
water heater electric, perchance, and you're getting localized boiling
off the heating elements continually generating the dissolved air? Is
there some local cavitation in pump doing something similar?

To minimize dissolved O2/air, if the system is filled and left open to
atmosphere, eventually it will come to an equilibrium point. This
could be accelerated some by pulling a slight vacuum on the system to
lower pressure (opening the pop bottle effect).

What's the rest of the piping, why isn't there a problem elsewhere in
the system? Also, replacing a steel tank (apparently unlined) tank w/
a stainless or lined one should elminate the problem from a different
angle.

I'd surely want to hear more from the system installer/manufacturer on
why I was having such problems if nobody else is--or what they're doing
for everybody if I'm not unique...

Just my $0.02, IMO, YMMV, etc., etc., ...

The sys has about 400 feet (4 separate runs) of PEX tubing (orange plastic tubing-designed for this sys,no oxygen barrier).I installed the sys (DIY),with help from manufacturer,company in Vermont,US. I spoke to them and they don't have any idea.Other sites have said the problem is no oxygen barrier in the tubing.I was told I didn't need one since I was using a gas hot water heater. Can't change the tubing so trying to find way of lowering the oxygen content.The only other idea was a plactic lined expansion tank.The problem is will the oxygen attack the copper tubing or the water heat if not that. Thanks for any help.

"BOB1901" wrote in message
...

HeatMan Wrote:
"BOB1901" wrote in message
...-

My expansion tank rust out in about 1 year.replaced 3 in about 4
years.I've been told its high oxygen in the water .How can I get rid
of
it.

-
Is the system open or closed?

It sounds to me like it's an open one and uses a expansion tank
designed for
a closed system.


This is a radiant floor heating system. The sys has an air
eliminator,operating pressure is around 15-20 lbs,temp is about 130
degrees and closed sys.The sys uses a hot water tank to heat the water.
I had tried anti freeze to act as a lubricant to stop the rusting of the
expansion tank (mixed a few gallons in to the sys),no luck. It seemed to
make the expansion tanks rust faster.First tank lasted about 18
months,second about 12 months ,third about 9 months. Any way of
reducing the oxygen in the water.


Next question. Do you know the name on the tubing?

Easy answer. Whoever did the install used non-barrier tubing. There is
virtually nothing that can be done as far as an oxygen scavenger that will
last.

My suggestion is to use an expansion tank for potable use.

Who installed the system? Was it one you got off an internet sales site?

"Robert Gammon" wrote in message
m...
wrote:
Edwin Pawlowski wrote:


wrote:



you won't get it all out because if you do and there isn't anywhere
for
the expansion, then the water will burst the pipes if it gets to cold.


The expansion tank is for warmer water, no?


High oxygen does cause corrosion. In industrial systems, the best way
to
get rid of it is to use sulfites as an oxygen scavenger...


Would this remove all the oxygen in the expansion tank? Seems unlikely.
Would pressurizing the expansion tank with nitrogen make it last longer?

Nick


The expansion tank allows for the expansion/contraction of water as it
heats and cools.

Dry nitrogen in the expansion tank will help with rusting on the AIR
side of the tank.

Oxygen dissolved in the water will eventually create bubbles in the
system that will have to be bled off,else the pumps won't work. Filling
a radiant loop with RO filtered water gets you VERY squeeky clean
water,but comes at a price of excess dissolved oxygen. If you can afford
it, then Distilled water is a better choice as there is no excess oxygen
generated in the production of distilled water. IMHO, Distilled water
or RO water are the only water sources that SHOULD be used to charge/top
off a radiant heat system.


Nope. If the OP has non-barrier tubing, there's really nothing that can be
done.

dpb wrote:
BOB1901 wrote:
...


This is a radiant floor heating system. The sys has an air
eliminator,operating pressure is around 15-20 lbs,temp is about 130
degrees and closed sys.The sys uses a hot water tank to heat the water.
I had tried anti freeze to act as a lubricant to stop the rusting of the
expansion tank (mixed a few gallons in to the sys),no luck. It seemed to
make the expansion tanks rust faster.First tank lasted about 18
months,second about 12 months ,third about 9 months. Any way of
reducing the oxygen in the water.


What does the installer say? Surely yours isn't the only one they've
done. What is unique about yours? If everybody has the same system,
they all should have similar problems. Failing help from the local
installer, have you contacted the system manufacturer for advice?
There are lots of radiant floor heating systems in use and I've not
heard of this being a generic problem so _something_ must be unique
here.

I've no direct experience w/ one of these systems, but I'm puzzled as
to how you're getting such high dissolved O2 to begin with. Is the
water heater electric, perchance, and you're getting localized boiling
off the heating elements continually generating the dissolved air? Is
there some local cavitation in pump doing something similar?

To minimize dissolved O2/air, if the system is filled and left open to
atmosphere, eventually it will come to an equilibrium point. This
could be accelerated some by pulling a slight vacuum on the system to
lower pressure (opening the pop bottle effect).

What's the rest of the piping, why isn't there a problem elsewhere in
the system? Also, replacing a steel tank (apparently unlined) tank w/
a stainless or lined one should elminate the problem from a different
angle.

I'd surely want to hear more from the system installer/manufacturer on
why I was having such problems if nobody else is--or what they're doing
for everybody if I'm not unique...

Just my $0.02, IMO, YMMV, etc., etc., ...


Another solution is to look for a Well Mate tank, all fiberglass tank
with REPLACEABLE bladder!!

Model WM-4 is 16 inches in diameter and 22 inches tall.

More expensive, but if you get 20 or more years of life out of it????

MFG List for a 14.4gallon tank with 30/50 draw down of 4.4gallons is
$275. Online retailers will discount to roughly $155. Interestingly
enough, a 20gal tank is $5 cheaper in some cases.

Now it becomes clear..

"BOB1901" wrote in message
...

dpb Wrote:
BOB1901 wrote:
....
-
This is a radiant floor heating system. The sys has an air
eliminator,operating pressure is around 15-20 lbs,temp is about 130
degrees and closed sys.The sys uses a hot water tank to heat the
water.
I had tried anti freeze to act as a lubricant to stop the rusting of
the
expansion tank (mixed a few gallons in to the sys),no luck. It seemed
to
make the expansion tanks rust faster.First tank lasted about 18
months,second about 12 months ,third about 9 months. Any way of
reducing the oxygen in the water.-

What does the installer say? Surely yours isn't the only one they've
done. What is unique about yours? If everybody has the same system,
they all should have similar problems. Failing help from the local
installer, have you contacted the system manufacturer for advice?
There are lots of radiant floor heating systems in use and I've not
heard of this being a generic problem so _something_ must be unique
here.

I've no direct experience w/ one of these systems, but I'm puzzled as
to how you're getting such high dissolved O2 to begin with. Is the
water heater electric, perchance, and you're getting localized boiling
off the heating elements continually generating the dissolved air? Is
there some local cavitation in pump doing something similar?

To minimize dissolved O2/air, if the system is filled and left open to
atmosphere, eventually it will come to an equilibrium point. This
could be accelerated some by pulling a slight vacuum on the system to
lower pressure (opening the pop bottle effect).

What's the rest of the piping, why isn't there a problem elsewhere in
the system? Also, replacing a steel tank (apparently unlined) tank w/
a stainless or lined one should elminate the problem from a different
angle.

I'd surely want to hear more from the system installer/manufacturer on
why I was having such problems if nobody else is--or what they're
doing
for everybody if I'm not unique...

Just my $0.02, IMO, YMMV, etc., etc., ...



The sys has about 400 feet (4 separate runs) of PEX tubing
(orange plastic tubing-designed for this sys,no oxygen barrier).

400 foot runs? What kind of pump do you have, a Taco base mounted one?
Pros never go over 300 feet.

I installed the sys (DIY),with help from manufacturer,company in
Vermont,US. I spoke to them and they don't have any idea.Other sites
have said the problem is no oxygen barrier in the tubing.I was told I
didn't need one since I was using a gas hot water heater. Can't change
the tubing so trying to find way of lowering the oxygen content.The
only other idea was a plactic lined expansion tank.The problem is will
the oxygen attack the copper tubing or the water heat if not that.

As I said, get an expansion tank for a potable water system. If you put
anything at all in the system, such as an oxygen scavenger, you'd better
have a double check valve or a back flow preventer on the system.
Otherwise, you may end up drinking, cooking with, or showering in your
oxygen scavenger. Betcha the Vermont company never told you that.

Thanks for any help.

Friend, your main problem was that you went with the possibly worst company
on the 'net. Sure, they were a lot cheaper than having a pro do it, but
look a the problems you've been having. That company sells rubber stamp
systems and their tech support is actually non-existent. They have your
money and don't really care for you any more, so they have no clue of the
problem you're having, even if they just got off the phone with the exact
problem with another customer.

Was an accurate heat loss done? A standard gas WH has an input of about 40K
BTU's. That may take care of and area of between 600 and 1000 square feet.
That ain't much.

Good luck. Go to the Wall and ask them about the Vermont company.
http://forums.invision.net/Main.cfm?CFApp=2

On Thu, 7 Sep 2006 17:57:43 +0100, BOB1901
wrote:


dpb Wrote:

Other sites
have said the problem is no oxygen barrier in the tubing.I was told I
didn't need one since I was using a gas hot water heater.

I've thought long and hard about this and have come up with NO IDEA
how someone dreamed up one is a factor of the other.


Can't change
the tubing so trying to find way of lowering the oxygen content.The
only other idea was a plactic lined expansion tank.The problem is will
the oxygen attack the copper tubing or the water heat if not that.
Thanks for any help.

You'll need to find a reputable chemical-man/water treatment company
(good luck on that. Ask some of the local manufacturing companies who
they use for their boilers and cooling towers) and have your boiler
water treated properly. Not a big deal.

-zero

zero wrote:
On Thu, 7 Sep 2006 17:57:43 +0100, BOB1901
wrote:


dpb Wrote:



Other sites
have said the problem is no oxygen barrier in the tubing.I was told I
didn't need one since I was using a gas hot water heater.


I've thought long and hard about this and have come up with NO IDEA
how someone dreamed up one is a factor of the other.



Can't change
the tubing so trying to find way of lowering the oxygen content.The
only other idea was a plactic lined expansion tank.The problem is will
the oxygen attack the copper tubing or the water heat if not that.
Thanks for any help.


You'll need to find a reputable chemical-man/water treatment company
(good luck on that. Ask some of the local manufacturing companies who
they use for their boilers and cooling towers) and have your boiler
water treated properly. Not a big deal.

-zero


In a closed system, and this one should be, distilled water has no
excess oxygen almost by definition.

So long as the boiler does not heat the water to more than about 150F,
no steam bubbles either

32094

My expansion tank rust out in about 1 year.replaced 3 in about
years.I've been told its high oxygen in the water .How can I get rid o
it


--
BOB1901

Hello Bob,

The corrosion in your expansion tank is due to dissolved oxygen in the
fluid attacking ferrous materials including the tank, circulating pump and
any other steel or iron component. The flexible radiant floor pipe you used
did not have an oxygen barrier to protect the system. The oxygen passes
through the wall of the tubing due to an imbalance between the closed
heating system and open oxygen rich envirnoment in our atmosphere.

If your floor heating system is connected to your hot water tank and the
DHW plumbing system just change the tank to the amtrol or equivalent
listed below. If your radiant system has a dedicated heat source in other
words it is a closed system your may have other issues and components to
change.

To eliminate your problem replace the expansion tank with a model suitable
with potable water systems such as the amtrol ST5 or ST12 and replace the
circulating pump with a bronze or stainless steel model. Your goal is to
replace any component not suitable for open potable applications. If your
system was installed by a professional plumber go back to him to remedy
this problem or if this was a DIY project then contact a radiant heating
designer at your local plumbing wholesaler for help.

If your heat source is a steel or cast iron boiler this item is also being
attacked. Your solution will also require a stainless steel heat exchanger
to isolate the tubing system from the heat source. Talk to a professional
in the future.

And you're JUST finding this thread?

The question was answered a long time ago.....


"galnorth" wrote in message
news:bda9ccd8e9dd0be22c928bf62dac3c9a@homerepairli ve.com...
32094

My expansion tank rust out in about 1 year.replaced 3 in about
years.I've been told its high oxygen in the water .How can I get rid o
it


--
BOB1901

Hello Bob,

The corrosion in your expansion tank is due to dissolved oxygen in the
fluid attacking ferrous materials including the tank, circulating pump and
any other steel or iron component. The flexible radiant floor pipe you
used
did not have an oxygen barrier to protect the system. The oxygen passes
through the wall of the tubing due to an imbalance between the closed
heating system and open oxygen rich envirnoment in our atmosphere.

If your floor heating system is connected to your hot water tank and the
DHW plumbing system just change the tank to the amtrol or equivalent
listed below. If your radiant system has a dedicated heat source in other
words it is a closed system your may have other issues and components to
change.

To eliminate your problem replace the expansion tank with a model suitable
with potable water systems such as the amtrol ST5 or ST12 and replace the
circulating pump with a bronze or stainless steel model. Your goal is to
replace any component not suitable for open potable applications. If your
system was installed by a professional plumber go back to him to remedy
this problem or if this was a DIY project then contact a radiant heating
designer at your local plumbing wholesaler for help.

If your heat source is a steel or cast iron boiler this item is also being
attacked. Your solution will also require a stainless steel heat exchanger
to isolate the tubing system from the heat source. Talk to a professional
in the future.