Steam Boiler failure

steve pajek

with Dan,Tony,and Ron. That indirect tapping appears to directly opposite that rust hole.

Just looking at Peerlesses web design cast iron section. Do you guys think that this is a good design for a steam boiler section? Seems to me that web section would load up with mud. An old time steamfitter had brought this up to us. What do you guys think??

Rick Rodriguez_2

Steam Boiler failure

I would be interested in hearing about anyone who had a steam boiler failure.
Especially if an indirect water heater was connected to the system or; there were no appearant leaks in the system which would cause exessive make up water.

Rick Rodriguez_2

To add a little infomation about the previous post. What I mean by failure is corroison in the steam chamber. Only in one section and it seems like the corosion is coming from the inside out.

Thanks in advance
Rick

Mad Dog_2

more details and pictures needed Rick

Mad Dog

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Rick Rodriguez_2

Since this can go in a few different directions what details would you like to know?
Would be happy to give them to you as this one has me stumped.
I have a picture of the broken section which I have attached.
This happened twice since installation was completed in 1997. The in both cases the section that failed was the same one in the same location the section next to it seems to be in tack.
Rick

Ken_8

Sure looks like

a casting defect to me!

I am puzzled as to how the large curved piece can be laying on the steam chest drum head, when gravity would have caused it to drop to the lower aspect of the area of the steam chest. Or did you simply let it lay where it moved to when dis-mantling the block to see what was up?

The casting was defective, leaked and caused wildly accelerated corrosion and caused the demise of the unit for sure.

What make boiler? How old? And most important of all, was it installed properly (hartford loop, riser sizing(s)etc.)

I assume it is a gas unit?

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Rick Rodriguez_2

The boiler was properly installed with a hartford loop. I used steel pipe with cast iron fittings using both 2" risers. Attached is a letter I sent to Peerless containing all of the details that I can think of with any pertenance to the failures.
The large curved piece is scale that ended up there as a result of me moving the section around.

Rick

peter desens

Steam failure


Just for the fact that this has happened twice, and in the same location of the boiler, you have to believe something is causing the failures other than a casting defect. If so, the new one won't last long either.

Casting defects are reletively rare. The failure donesn't look like the result of a sand hole, nor a crack. Looks more like the water side of the iron was worn away in that one spot.

A few questions ,

Manufacturer of boiler?
Oil or Gas?
State and town boiler located?
Well or City water?
Single or two pipe system?

Rick Rodriguez_2

I tend to agree with you that its not a casting defect.
I posted a reply with an attachment that explains a lot of what happened. It is a one pipe steam job installed in New Jersey

Rick

Steamhead

Adding 2 inches of water

every month may or may not be too much. It's hard to tell from the pics, but did the leak occur at the same height the water level was maintained at?

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[Deleted User]

Is the rotted

iron directly across from the return inlet from the indirect?

Rick Rodriguez_2

The leak happened above the maintained water level.

Rick

Rick Rodriguez_2

The failed section is the one that receives the return from the indirect.


Rick

RonWHC

I think you are

creating a nozzle effect on the section wall. Washing it out. The 60 gallon indirect suggests mucho usage. If you think of each section as a separate boiler, you can see that you are asking one section to do the job of all four.

On summer/winter steam sectionals we tap all sections and manifold them together for external heaters. But, you need a boss on each section below the water line. Might be time to consider a different H/W arrangement.

Rick Rodriguez_2

I'm under the impression that the indirect has something to do with the problem. In the absense of an other culprit.

Rick

Rick Rodriguez_2

The boiler has 4 sections and on the original installation and on the first replacement I used both return tappings.
The indirect went into a tee that was connected to the failed section by a close nipple the bull of the tee went around to the other side connecting to the other return tapping. Don't see how I could connect all the sections.

Rick

paul lessard_3

What about

Flue temps? just a thought

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Rick Rodriguez_2

I did't get any flue temps. I was told that I would get corrrosion in the flue pipe which dosen't really seem to be happening.

tommyoil

Do you have

an automatic water feeder on the unit? If not, how often do you add water? Kinda looks like oxy corrosion to me.

Tony Conner_2

This...

...looks like erosion damage, as opposed to a corrosion issue. I've seen a simliar damage pattern on an industrial deaerator. (The feedwater tank in industrial boiler rooms, where steam is fed into the them to drive-off dissolved oxygen.) It was due to steam bubbles collapsing when the cold water make-up hit the tank. (The wrong unit was selected for the service, plus it was a crappy design anyway.) The water rushing in to fill the void left by the collapsing steam bubble literally scoured metal off the tank. The exact same thing happens when a pump cavitates, and you can see metal gouged off the impeller.

Bear in mind that erosion can be caused by things other than collapsing steam bubbles, so that particular event may not be occuring inside this boiler. But it DOES look like erosion damage.

[Deleted User]

The supply

to the indirect, off the boiler return tapping, is OK. Ideally, the indirect return should dump back into all sections, not just one, below the water line. No openings in the 61 steamer for that. Maybe a separate boiler for the indirect?

Rick Rodriguez_2

Any suggestions for troubleshooting the cause?

Rick

DanHolohan

I'm with

Tony and Ron.