rubber hose with oxygen barrier ??

ALH_4

I peeled apart a piece of Onix, and that barrier sure resembled foil-laminated <a href="http://www.dupontteijinfilms.com/datasheets/mylar/productinfo/properties/h37250-1.pdf"target="_blank">Mylar</a> polyester film to me rather than aluminum foil. I do not know what Watts officially says it is, but if it is Mylar, there is some permeability to it, just like the foil balloons. I haven't investigated it deeply enough to compare an EVOH barrier to a foil-coated Mylar Film.

ScottMP

Took this circulator

out of a house yesterday. The copper finned tubing was piped in Black Rubber Hose made for hydronic piping by a major manufacturer.

This is in a condo development done by an out of town company about seven years ago. Many of these unit have the same system. We pulled a circulator from a unit last year with the same symptoms.

Take a look at the volute and the impeller. I belive that oxygen is getting into these systems. The only solution ( short of re-piping ) is a flate plate heat exchanger and bronze pump on the system side.

And no its not the water as this is town water that we use on all our systems with No Problem.

Scott

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

scott markle_2

aluminum barrier ?

Without naming names,( Which there seems to be a certain sensitivity to here) is this a newer generation tubing with an aluminum foil layer type barrier? If not, the HX is probably mandatory. The failed rubber products of the past suffered the most in high temperature applications. Seem like a good idea to avoid high (180 +) temperatures with materials that could experience degradation from those temperatures. I wonder if pex also could also experience accelerated aging from such. Any opinions on that subject.

scott markle_2

aluminum barrier ?

Without naming names,( Which there seems to be a certain sensitivity to here) is this a newer generation tubing with an aluminum foil layer type barrier? If not, the HX is probable mandatory.

scott markle_2

aluminum barrier ?

hr

make up water?

could it have a leak somewhere allowing fresh water in?
Any non barrier pex in the system?

Ever now and then I see a O2 barrier rubber hose system with sludge and corrosion issues. Bath it with Rhomar and use their conditioner.

If in fact it has the aluminum wrap in the tube it should be 100% O2 barrier. Same with PAP.

Pex with EVOH barrier is not 100% from what I'm told. Higher operating temperatures increase the O2 ingress.

hot rod

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

ScottMP

Should be but

apparantly its not. Can you see the rust build upin the volute of the circ ? This is'nt sludge its rust. Look at the impellor its been grooved away in places.

There is no other tubing in these town houses. I can't see how conditioning the water is going to stop rust build up like this. Maybe sludge. We actually treated this boiler with TSP about three years ago and then totally flushed it again.

This is a nice little place, we'd see a leak if it had one.

???

Scott

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

ScottMP

Scott

This is a 3/4 black hose. There is a name on it and Yes I am trying to be sensitive here.

We did not remove any tubing so I can't be sure about the barrier .

Scott

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

scott markle_2

black pipe

The black pipe named after a stone has an aluminum barrier. oops I'm a few posts behind on this. mylar or true aluminum? hum, The stuff I used recently did feel rather stiff.

hr

If in fact

you determine is is allowing O2 in then the choices are...

Use all non ferrous components

Isolate the non ferrous from the tube, possibly a Taco X block

Use a product like the Rhomar conditioner which has O2 as well as corrosion inhibitors.

If it is allowing O2 in the conditioner will need to be checked and boosted from time to time.

It sure looks like rust build up has got in the way of the disposal, er I mean impeller

hot rod

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

ScottMP

Do you mean

seperate the ferrous from the tube, right ?

Taco x-block ?? I never thougth of that ?

I'll check into that and see. Do you think it can move enough btu's ?

I checked and it seems to max out at 50,000 btu's !

Scott

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Chris_82

With all due respect you might want to take apart other circulators that have been running for a couple of years, because those pictures don't look all that bad? How long was it running? Seeing that it's black, which Taco has only been doing for the last 4 years,? Not sure?
But having lived thru the inital o2 problem your pictures, although very nice, don't come anywhere near the amounts of damage caused by non-barrier tubing in only a few weeks of operation. Nevermind the big problem that was chewing up the CI in the boilers.

ScottMP

Point taken

The problem with this one ( and the other ) was the screaming noise form the circulators where the impellor was hitting the build up.

Somthing we don't come across that.

I'm open to suggestions.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

[Deleted User]

I have a theory...

And by the way Scott, you are not alone in your findings of significant corrosion on systems with this product being used.

I may have to draw you a picture later to drive my point home, but maybe the picture I paint with words will satisfy your minds eye.

Think of how the onyx (everyone knows who's tube it is, why beat around the bush) is made. An inner hose, a middle mylar layer, and an outer protective hose/cover. Now, think about how it is fastened to the barbed fittings. There is a small section of hose that is intimately in contact with the barbed fitting. This hose has an "exposed" end at every barbed fitting, and it's the point where I believe the majority of the oxygen ingression is occuring. It is flowing parallel to the barbed fitting, through the inner tube, and into the working fluid. The hotter the fluid, the more/easier the ingression. The mylar O2 barrier works great for oxygen trying to pass through the hose mid hose at right angles, but does literally nothing for the flow of oxygen at the end of the cut hose.

Just a thoery mind you, but a plausible one.

Oxygen is known to pass through rubber gaskets on pumps, packing glands on valves, bladers on expansion tanks and obviously the ends of the tube where it has been cut.

Again, I don't think there IS a tube (even copper systems) where oxygen can NOT make it into the system. As long as you know it's going to show, why not accomodate it with corrosion inhibitors, just to show IT who's boss :-)

My German friend in the mountains is seeing a LOT of obvious O2 ingressed systems that used Onyx hose...He has flushed with Rhomars strongest cleaner until he's blue in the face, and it STILL comes out dirty.

Not a good sign, but then again, it's a known fact that I am not a real big fan of putting anything that resembles rubber hose into a heating system.

Need a drawing or did I paint a clear picture???

ME

Chris_82

In that case did cleaning the impeller cavity help? I'm sorry I can't find the old pictures perhaps someone else has some, but the damage from the original entran and other tubing that didn't have any barrier was increddible, the diference was immediatly and unmistakingly noticable. I see only minor rust bubbles in your pictures and they just don't look any different from any other circulator that has been in service for a couple of years. Is there any chance some slag chips or a CI radiator is in the system that had some stuff left over? Generally the cartridges are the noismakers, in which case build up of material just either stops the unit or they keep running. The other point is the vast majority of impellers are plastic and very trouble free. So once again what happened after you cleaned them off?
On another note if it's connected in a system heated with a Munchkin just include the cost of a new circulator with the cost of the new munchkin, every five years or so...

ScottMP

Take a closer look at the impellor

We did'nt try to clean the impeller cavity. We changed out the whole circ. As you can see from the photos, the impellor has been grooved. Its cheaper to put in a new circ.

I agree this is Not Catastrophic but the system has been in for six or seven years and the next door nieghbor had the same problem last year. The circ was whinning and Not moving the water.

I think we may have a "poor" barrier here and we are getting "some" oxygen invassion.

This system is all copper fin tube with a Super-Stor indirect. Some of the other homes have had Vaughn stone lined tanks that have failed in the first three years. Not shocking but could be to oxygen ?

Point taken on the boiler replacement

I think we may have a Poor oxygen barrier here and its going to keep have problems.

By the way, one of the owners of these units asked me why it took so long for the third floor to heat up after reset at night. After checking it out, I told him it was because the installer put the copper fin tube element in sideways. Checked the whole house .... yup .. all in sideways. Looks like they where all done that way.

Nice job, good price. Now the current owners pay for the mistakes.

Scott

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"