Rust Lots of Rust

hr

I'd bet it leaks when the boiler is cold and "takes up" and stops when the boiler heats up. A seasonal leak so to say :)

hot rod

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Devon_2

Rusty Pipe out of Boiler

I have a Dunkirk light oil fired boiler that is 2 years old and I have a severe problem with rust on the outlet pipe. I have attached two pictures to illustrate the problem. I think it is caused by the connection of iron to copper. I plan on removing the rusty section and replaceing it and I need to know how to prevent this problem from happenning again. I need to put a 1&1/2 inch 90 then a nipple then a copper reducing coupling into 3/4 copper pipe.

Al Gregory

Female adapters tend to do that sometimes. Especially if they were eggshapped when they were tightened.

Unknown

as I said before

Never, never use female adts onto male pipe threads of any materials... Use a nipple with coulping and the male adt to it, more forgiving and no leak!

Devon_2

Next Steps

I attached a picture of the elbow part of the section that I need to replace. What metals should I use? i am trying to go from 1/2 nipple to 3/4 copper Do I need a di-electric union?

right now its a galv 1/2 ell to black nipple to galv reducing coupling (f/f) to black nipple to copper reducing coupling to another coper reducing coupling soddered to 3/4 copper pipe.

Ron Schroeder

I would

get rid of any Galvanized pipe or fittings they will be your worst nightmare when it come to corrosion, skip the di-electric union and either use a Brass Coupling or even better a Bronze Valve for isolation.

Devon_2

Thanks

So I should use black pipe nipples with brass couplings? Should I seperate the black pipe and copper with brass to prevent corosion?

Ron Schroeder

I have used copper to blk many times

with no issues but to be on the safe side use the brass to seperate the black from the Copper, use blk nipples and fittings just use the Brass to seperate copper to black pipe.
Brass is in the middle of the metals that react to each other, Galvanized pipe and fittings are at one end and are a prime reason for Galvanic reaction whereas the Brass is closer to cast and blak pipe on one side and copper that is on the other.

ALH_4

Corrosion

I wouldnt worry about dielectric fittings. Your problem is the leak and oxidation of the iron, not galvanic corrosion. I would just fix the leak and replace any particularly badly rusted pipe. Go Steelers.

-Andrew

Bob Sweet

That's a leaking thread problem not electrolysis imo. But I'd stay away from using galvanized pipe, the galvanization has the potential to flake off and cause other problems within the system.

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Brad White_117

Chicken or Egg

I would suspect that the leak is secondary to dielectric corrossion... time is running out and the vicious cycle accellerates.

I agree with Bruce, brass nipple to black iron (fitting/coupling, not steel pipe) or better a bronze ball valve).

My $0.02

Brad

ScottMP

Brad

One Friend to another ..

I could'nt disagree more. There is NO electrolosis going on here, its a leak pure and simple. The original installation was tight and it leaked and dryed, leaked and dryed. Multiply that a couple of hundred times and thats what you have. See it all the time, never got a tee-shirt.

We Install systems every other day with copper to steel connection in heating systems with no sign of electrolosis.

Every Header I have ever installed has a connection to copper at some point. I have very few call backs.

This job just needs to be re-piped with black mallable fittings and copper x male adpts.

Check out the returns on this photo. This is a customer we service Every Year.

Scott

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Brad White_9

Thanks Scott

I do not see any F copper to M iron in there. Brass nipples and valves maybe.

I am not discounting the leak as being first, just that one may beget another; something else to think about.

Some joints I have seen have electolyzed almost overnight (stray current was suspected) and as you said, sometimes copper to steel holds up just fine.

As always, I trust reality (even if borrowed from you) over theory any day- so always call me on things.

Thanks, Scott-

Brad

ScottMP

I agree with Hot Rod

and Brad I am going to be rather adament here, I did'nt say "sometimes" copper to steel holds up just fine. I have been installing boilers for close to 25 years now ( did I just say that ) and have been using copper to steel conections with NO problems. This issue seems to come up on the wall every now and then and someone is always looking for an answer. The answer is a leaking joint.

If you look at my photo, on the returns, there are No brass nipples or ball valves to isolate. Maybe on the feeds yes but those are mallable tee's with copper x make adpts.

Scott

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Brad White_9

Easy, Scott...

Just going by what I see in the photos- copper to iron (not steel) fittings which I endorse as acceptable. You also have brass or bronze ball valves which are also OK by me.

It is copper to steel of which I am wary. I see none of that in your photo unless I am missing something.

We do agree.

Unknown

> One Friend to another ..

>

> I could'nt disagree

> more. There is NO electrolosis going on here, its

> a leak pure and simple. The original installation

> was tight and it leaked and dryed, leaked and

> dryed. Multiply that a couple of hundred times

> and thats what you have. See it all the time,

> never got a tee-shirt.

>

> We Install systems

> every other day with copper to steel connection

> in heating systems with no sign of

> electrolosis.

>

> Every Header I have ever

> installed has a connection to copper at some

> point. I have very few call backs.

>

> This job

> just needs to be re-piped with black mallable

> fittings and copper x male adpts.

>

> Check out

> the returns on this photo. This is a customer we

> service Every Year.

>

> Scott

>

> _A

> HREF="http://www.heatinghelp.com/getListed.cfm?id=

> 237&Step=30"_To Learn More About This

> Professional, Click Here to Visit Their Ad in

> "Find A Professional"_/A_

Unknown

Scott , I could not agree more

Every boiler we replace , and every one we install has at least a few copper to steel , copper to iron male or female connections . Any adapter that developed a leak was easily fixed by redoing the thread sealant and socking the sucka down even more . I guess a leak can occur through electrolysis , I am positive it is not the cause of 99.99 percent of thread leaks . If it truly was electrolysis , why that one thread ? The more obvious cause is a fitting loosening up after soldering the adapter . Now THAT is what we see quite often .

By the way Scott , that boiler room is damn beautiful .

Cosmo_3

chiming in

I think most copper to iron/steel leaks are caused by the different rates of expansion of the two materials.

Our dead men have taught us to always use a male copper fitting when going copper to iron/malleable/steel.

I have NEVER had a case pulling apart old systems, where the copper I felt was damaged by electrolytic action. I am not a scientist so I cannot prove it is not happening, but forty year old systems that are still solid is good enough I think.


Cosmo

Al Gregory

It looks like the pipe was probably soldered on after the adapter was tightened up too. Should have soldered the pipe to the adapter and let it cool before attaching it to the nipple

ScottMP

O.K.

I'll give you that.. no steel.

But tell me, why would the non-ferrous ball valves be O.K. but not the copper ?? I understand the different expansion rates and that could be an issue, but brass or copper, why one and not the other.

Hugs and Kisses

Scott



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ScottMP

Thanks Ron

Thats an old one but its a good photo.

I got some real Purty ones, coming up !

Scott

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hr

Good point, Al

solder, cool, and clean the flux out before you dope and thread any copper to mip or fip adapter. Nothing like bubbling, stinking pipe dope.

Although I have heard of fitters getting a buzz from burning RectorSeal (rectum seal) #5.

hot rod

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Brad White_118

Steel vs. Copper

The reason the copper has fared well is that it is the more "noble" metal. The steel would be sacrificed as an anode while the copper is the cathode. Short answer I know!

Brad White_118

The ball valves

I am told mimic dielectric waterways, that the PTFE (Teflon) cores isolate the metals to a satisfactory degree.

Love you too.

ScottMP

My Honest opinion

I think this is a Non-issue.

I do not belive that electrolosis (sp) is common enough in a closed system to warrant concern. Die-electric unions are a waste of time.

As Cosmo says I have opened Many old systems and found no evidence of galvanic action. I think I have a few years of field experience to say this .

Although frowned upon I have seen many Female to steel pipe connections with out failure, that have been installed for many years, to make me feel this is not an issue.

Scott

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Ken_40

I concur,

Mr. Milne is correct on all counts.

Failure to use the proper dope, wrenches, and torque are the cause of 99.9999% of all hydronic system leaks.

And, despite what was stated about C X F adapters, if the correct dope is used AND a box wrench or anything BUT a pipe wrench is used - they work perfectly well too!

jackchips_2

Early in my

career I learned to stay away from female adaptors.

Just shows you are never too old to learn. I would never have given thought to the pipe wrench affecting the fitting until now.

Thanks Ken,

Jack