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 Post subject: Re: Boiler Watch Leaking Flue
PostPosted: Sun Apr 17, 2016 10:46 pm 

Joined: Fri Mar 26, 2010 11:43 am
Posts: 777
NYCRRson wrote:
MAYBE YOU SHOULD CONSULT YOUR LOCAL EMERGENCY SERVICES PERSONNEL ?


This part I take particular exception to. Maybe they will go on BLEVE protocal and throw you out of the area, evacuate the area to some massive distance, and start hosing the thing down with icewater? Bottom line, is when EMS gets there, they can take over, establish their own plan of action, and very likely will give almost zero thought to preservation of a historic artifact. There are times for EMS but there are also times, when you have a specialized situation, that they are no help, or can make things worse...


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 Post subject: Re: Boiler Watch Leaking Flue
PostPosted: Mon Apr 18, 2016 12:45 am 

Joined: Thu Aug 05, 2010 2:06 am
Posts: 386
Steven,
Please don't be frightened by the overreactions offered but I'll temper that by saying only some has been overreaction.

You do have a very serious leak from that flue and beside the fact it creates a pain in the butt to fire against, the flue could crack or collapse and fill the cab (and immediate area) with fire, ash & steam. I don't believe the flue collapsing would create a BLEVE because the rest of the firebox is not in a compromised condition (my opinion & worth what you've paid for it). There are many written accounts of engine crews battling with a crying tubesheet and living to tell the tale. Mostly it was a great deal more work for the fireman.

I do agree with the comment that the dragon is being poked. Were it my skin I'd respectfully either refuse the assignment or tend the engine only to let the fire go out to facilitate repairs.

I'd say you were right on by stopping the cold air inrush because you saw that was making things worse.

I've never heard of putting another ring inside and then expanding that to try to seal things up. Because of that, I'm skeptical. That certainly doesn't make it wrong and I'm guessing it is a technique that didn't make it to this side of the big puddle.

I hope the engine makes it to the repair without further incident.....mld


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 Post subject: Re: Boiler Watch Leaking Flue
PostPosted: Mon Apr 18, 2016 1:43 am 

Joined: Sat Feb 05, 2005 1:05 am
Posts: 481
If your boiler-maker/inspector/guru does not know exactly where and why the tube is leaking, it should be removed from service.
If it was rolled more than twice, under working pressure hydro just enough to make it tight, it is over rolled and failure is imminent.
If the boiler was not baked dry during the off season, corrosion continued to decrease the tube wall thickness during the layup period.
Attachment:
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extra844.jpg [ 58.08 KiB | Viewed 8535 times ]


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 Post subject: Re: Boiler Watch Leaking Flue
PostPosted: Mon Apr 18, 2016 3:35 am 

Joined: Wed Jun 13, 2012 10:38 pm
Posts: 343
Location: Copenhagen, Denmark
quick notes for everyone on the situation

-Copper firebox, steel tubes and flues
-most definitely a leaking flue, leak comes from edges of the flue and sheet

Depending on what time of the day it was, the leak would react differently. Before firing the boiler up we noticed a bit of a calc stain around the flue, but nothing bad. During firing up nothing was leaking. When we started out the next morning there was nothing. After getting to downtown Copenhagen from 20km away, the flue showed very small signs of leaking. One round trip on the line we were doing that day (35km) ended with us back in Copenhagen and absolutely no leak from the flue, even after sitting with a colder fire for an hour in Copenhagen.

Following that the flue only started leaking again at the turnaround point on the second trip. Running back to Copenhagen required the front damper open one notch and the rear open full (running in reverse) to keep the front left corner lit. About halfway back I was able to close the front damper and the corner stayed lit. Same issue after dropping the coaches in Copenhagen and running light to home shop (another 20km).

After getting back to home, we brought the locomotive in and removed the fire door air hood. With the hood removed, we were able to take a flashlight and look above the brick arch at the flue. A half hour after coming home, there was noticeably more water leaking down the tube sheet. The leak had developed to a jet of steam leaking from the top part of the flue, hitting the crown sheet. This jet was about a 1/16" in diameter. After that it basically comes down to what my dad said. It seemed to be the same all night, but slightly better when the grate was covered.

A bit to my surprise, the crew for the next day decided to run and from conversations I had with them later, it was basically the same all day long. We have trips friday, saturday, and sunday, and I honestly doubt we will have the problem solved before then. I am quite worried about steam cutting on the tube sheet once the leak developed to a small jet of steam from the edge of the tube. We will attempt to first expand the tube regularly while the boiler is being hydro'd. Then the two top machinists in the shop have the idea to try the steel collar inside the tube that then is expanded. We will see how things go, but I am betting on no steam this weekend with our loco, and the tube requiring replacement. I will be able to get photos of the situation tomorrow when we start working on the issue (after the boiler has cooled down a bit)

A bit of extra information:
Danish practice is to run with the fire door slightly open, providing secondary combustion air. This practice requires a u shaped metal hood to be installed in the fire hole that directs the secondary air under the brick arch, preventing it from hitting the tube sheet. Fireman are also trained to leave the middle of the grate open at long halts. Mostly this means only adding fresh coal in a ring against the sheets while leaving whatever is left burning in the middle alone, sometimes exposing the grates in the center. Banking the fire for the night is also an interesting practice, in which we are to only have fire in one corner of the firebox. We wait until there is only embers in a small pile in the corner, then shovel 25 scoops of fresh coal on top of the pile. By morning the majority of the pile is on fire, and the pile is raked to fill the firebox. The rest of the firebox is left bare and dark during the night, effectively leaving 7/8 of the grate to admit cold air. Max operating pressure of the boiler is 12 bar and the night fire practice is done when there is 5 bar in the boiler.

I would most definitely not be surprised if these practices helped contribute to creating the leaking tube!

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Stuart Harrod
Steam shop machinist
Nordsjællands Veterantog
Veterantoget.dk


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 Post subject: Re: Boiler Watch Leaking Flue
PostPosted: Mon Apr 18, 2016 5:16 am 

Joined: Thu Apr 14, 2005 9:34 pm
Posts: 2827
Location: Copenhagen, Denmark
Could be worse. Somebody could have asked me to climb into the return chamber of a hot wet back Scotch boiler to hammer a plug into a leaking flue. I definitely would not do that.

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Steven Harrod
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Danmarks Tekniske Universitet


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 Post subject: Re: Boiler Watch Leaking Flue
PostPosted: Mon Apr 18, 2016 5:21 am 

Joined: Thu Apr 14, 2005 9:34 pm
Posts: 2827
Location: Copenhagen, Denmark
Is hammering a solid plug into the flue a safe option? We would take that flue out of service, but would it be mechanically sound, assuming this is an over rolled flue?

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Steven Harrod
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 Post subject: Re: Boiler Watch Leaking Flue
PostPosted: Mon Apr 18, 2016 7:27 am 

Joined: Tue Aug 24, 2004 6:30 am
Posts: 768
softwerkslex wrote:
I have been asked to be night watchman. I have been asked to keep the engine hot at about 3/4 regular pressure, and we will not bank the fire. What safety precautions should I keep in mind tonight?

With all due respect, but why is someone that has to ask that question baby sitting a boiler? Not good.


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 Post subject: Re: Boiler Watch Leaking Flue
PostPosted: Mon Apr 18, 2016 7:35 am 

Joined: Sat Feb 05, 2005 1:05 am
Posts: 481
It is recorded that hammering a wooden tapered plug was a common roundhouse fix to keep a boiler in service until they could get it to a shop. It burns off next to the tube sheet but swells when soaked by leaking water. I have done this a few times on small plantation boilers to shut up pinholes just inside the tube sheet, just until we could get a steel tapered plug made. The unwritten Boiler Inspector rule was to allow up to 10% plugged tubes in a boiler.
I had dealings with a garbage burner powerplant that had primary superheaters made stainless steel. It went in service in May. First failures were in Sept. The chlorine in the burning plastics was causing chromium chloride salt precipitation/erosion in the s/s superheater grain boundaries. They had new superheaters made from Chrome-Moly onsite in Dec. waiting for a Feb. shutdown. In Jan. they could not stay online more than 3 days between failures and took it offline a month early.
It does not have to be perfect if common sense decisions are made grounded in knowledge, experience and good judgement.


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 Post subject: Re: Boiler Watch Leaking Flue
PostPosted: Mon Apr 18, 2016 7:39 am 

Joined: Sun Aug 22, 2004 7:19 am
Posts: 6464
Location: southeastern USA
No. The rolled portion of the flue is already compromised if it is overrolled. Suck it up and replace the flue. The note about starting with a scale stain and growing from there is pretty informative, and does not speak well about water treatment and layup practices. Like Matt, I've plugged a tube or two for temporary repairs, but to deal with leaks from oxygen pitting through the tube wall or something similar, not structural weakening from mechanical means compounded by erosion at the tube / sheet connection.

softwerkslex wrote:
Is hammering a solid plug into the flue a safe option? We would take that flue out of service, but would it be mechanically sound, assuming this is an over rolled flue?

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“God, the beautiful racket of it all: the sighing and hissing, the rattle and clack of the cars over the rails. These were the sounds that made America the greatest country on earth." Jonathan Evison


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 Post subject: Re: Boiler Watch Leaking Flue
PostPosted: Mon Apr 18, 2016 8:35 am 

Joined: Sat Feb 05, 2005 1:05 am
Posts: 481
Yea, what Dave said...
Dave wrote:
not structural weakening from mechanical means compounded by erosion at the tube / sheet connection.


Pegasuspinto wrote:
NYCRRson wrote:
MAYBE YOU SHOULD CONSULT YOUR LOCAL EMERGENCY SERVICES PERSONNEL ?


.....There are times for EMS but there are also times, when you have a specialized situation, that they are no help, or can make things worse...


In 2003, the Los Angeles Live Steamers had a derailment. Someone dialed 911 and said "train wreck" with this result:

LAFD Report

LAFD Incident #0533

Injury Incident
5202 West Zoo Drive
Los Angeles, CA 90027 USA

DATE: 11-02-2003 TIME: 13:37
1ST IN COMPANY: RESCUE 856
ADDRESS: 5202 WEST ZOO DRIVE
"Los Angeles Live Steamers" Miniature Railroad

FIRE STATION DISTRICT: 56

INCIDENT COMMANDER: BATTALION CHIEF JAY TURNER
OCCUPANCY TYPE: AMUSEMENT
ADULTS INJURED: 3
MINORS INJURED: 1

TOTAL FIREFIGHTERS: 60
TOTAL RESCUE AMBULANCES: 12
TIME TO CONTROL INCIDENT: 10 MIN
INCIDENT DURATION: 1 HR 15 MIN
TOTAL COMPANIES: 12

http://www.chaski.org/homemachinist/vie ... 708#p30708


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 Post subject: Re: Boiler Watch Leaking Flue
PostPosted: Mon Apr 18, 2016 8:50 am 

Joined: Thu Apr 14, 2005 9:34 pm
Posts: 2827
Location: Copenhagen, Denmark
Quote:
With all due respect, but why is someone that has to ask that question baby sitting a boiler? Not good.


Yes, but at least give me credit for asking questions.

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Steven Harrod
Lektor
Danmarks Tekniske Universitet


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 Post subject: Re: Boiler Watch Leaking Flue
PostPosted: Mon Apr 18, 2016 9:36 am 

Joined: Tue Sep 14, 2004 7:52 am
Posts: 2477
.


Last edited by Kelly Anderson on Sun Dec 08, 2024 1:18 pm, edited 1 time in total.

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 Post subject: Re: Boiler Watch Leaking Flue
PostPosted: Mon Apr 18, 2016 9:58 am 

Joined: Mon Aug 23, 2004 9:18 am
Posts: 725
Location: Wall, NJ
Kelly:

My experience on 3' gauge equipment over 30 years or so, would have been to take the engine out of service on a rather timely basis. We did not run engines with leaky flues, but is there some amount that is acceptable where perhaps you want to finish out the day? My view is no, but is that over reacting?

Appreciate some professional insight into that question.

Many thanks,
J.R.


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 Post subject: Re: Boiler Watch Leaking Flue
PostPosted: Mon Apr 18, 2016 10:23 am 

Joined: Tue Sep 14, 2004 7:52 am
Posts: 2477
.


Last edited by Kelly Anderson on Sun Dec 08, 2024 1:18 pm, edited 1 time in total.

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 Post subject: Re: Boiler Watch Leaking Flue
PostPosted: Mon Apr 18, 2016 10:45 am 

Joined: Mon Aug 23, 2004 9:18 am
Posts: 725
Location: Wall, NJ
Kelly:
Many thanks. I only ever operated on a 3/4 mile loop so never far from a diesel back up or a second steam locomotive that could be fired up for the next day’s operation. We erred on the side of caution and just took the engine out of service once the back up was ready to come on line. Beyond that, nothing special was done with the shut down procedure. Anyway, interesting to understand more of a real world scenario.

Thanks again,
J.R.


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