So, K582 has developed a flue leak today. It is essentially our second day under steam of the season since boiler washout. The flue was re-rolled over the winter because of known leaking problems last season.

We are supposed to run tomorrow. 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?

Numbers 1, 2 & 3 are:
Where's your water?
Where's your water?
Where's your water?

Now I'll ask how much of a leak is a leak? I realize it is extremely difficult to convey by typing, but is it just a sizzle around the end of the tube? Is there a spray? Is it enough to make water run down the sheet to the next tube or beyond? Is it coming from around the bead (the outside of the tube) or is it a pinhole in the tube?

It will do nothing but get worse, so keep an eye on whether or not the leak increases. A boiler will tell you what is going on with it if you're sharp enough to listen. Unless it was a single improper installation, one leaker is a warning there will be more. The ideal answer would be to shut down, repair that tube and any of the neighbors that get disturbed in the process and fire back up. I realize sometimes that is not given as an option but the crews should be aware that option may be forced upon them.

Steam safely & I hope she holds until a repair can be made...mld

Don't know. Getting called in by phone. I was not on duty today. I do know it was intermittent today, and seemed to get worse at shutdown.

I take it that when you say 'flue' you mean there is a superheater element in it. If not, is there a reason this could not be plugged, for example with conical plugs at both ends of the flue drawn up with nuts if tapered plugs could not be driven in? I would be tempted to ask if the header ports to the involved element could be blanked off and tne element pulled to facilitate plugging, if there is one.

You would not lose much heating surface, would not stress your boiler thermally in any meaningful way, and provide positive mechanical reinforcement at the tube-sheet joints if there is any compromise or wasting. (And of course block off seepage inside the flue).

Not elegant, of course, but I think it fixes the situation safely enough to operate until you can go in and repair things right.

Don't stand in front of the firedoor.

I simply would not run with that engine. Safety first, no supposed to run tomorrow unless you have a spare engine.

The reasons to keep it hot is to help boiler stresses, but keep the water up.
But let the pressure down..erm.. a lot.

If the proposed cure was rerolling, the diagnosis must have been leaks around the periphery. So, you need to know how thick the tube wall was and how much it has been rolled thinner - if thin enough, it could crack through the end and turn a small leak into a real problem. If the leak had been permitted to grow before last seasons end, there could be steam grooving affecting the ID of the tube hole where it leaked - the water flashes to steam when it gets free of the boiler. Also, depending on water quality, scale could have formed there and crushed during reroll, maintaining a leak where the tube can't fit metal to metal. It would take more than rerolling to fix this. A lot of old boilers in old service would leak cold, but "take up" when under hot steam - Lima sent booklets out with their Shays explaining this as a natural phenomonen - having had a lot of experience with Lima boilers and found them of very high quality, I think they were heading off incompetent operators more than anything else. Plugging a tube that isn't leaking from something like an oxygen pit or crack through the tube wall won't help.

Please try - the next time you're cold - rolling the tube under hydrostatic test pressure of at least the operating pressure with warm water. If that stopes the leak, just a bit tighter could do the job. Good luck.

Update.

So, I spent the night watching the boiler. I am told it is a superheater flue, not a tube, that is leaking, but there was no way for me to see because the engine has an arch. I did see a lot of water. There was enough water that I could not keep the far left corner burning.

When I arrived they had a full glass and pressure at the maximum. To try and cool things down they raked the fire off the middle grate, and then I took over. It seemed to me that the leak became worse then. I worked on the theory that cold air was making the leak worse. I returned the fire to complete coverage and tried to keep it burning. It seemed to me the leak was less with cold air eliminated. I had a hard time doing this on an idle engine, so I ran the air pump and accessories to use steam.

The engine ran excursions today. I am told the next plan is to insert an internal collar or bushing in the flue and expand that.

ah, didnt know it was the superheater,, you might have a slight lack of power, perhaps slight, probably to detect its really a superheater is to look for steam coming out of a flue or in neutral maybe see more steam out of the stack, but depends on the size of the leak. Glad you had the trips.

A simple weld on the superheater leak tube may fix it. May as well inspect the flues when the engine is down and the rest of the superheater tubes if possible and clean them flues out...8-P

I think he means it is a tube/flue/whatever you want to call it that contains a superheater is leaking. Not the superheater itself.

If the 'joint' is leaking, why not seal weld the tube? (Not possible if you have a copper tube). If it's copper, could he use something like sil-fos or a like brazing alloy to get the job done?

Or maybe it's just time to fix it right...

I respectfully suggest your group stop fooling around with this thing and fix it right,
right now.

You are poking a dragon now, and when (not if) he wakes up, it won't be pretty.

I value all the comments and am glad I have this forum to receive them.

I reread your description, with the throttle closed and still leaking you have a flue leaking.

The throttle closed might have a mini hole for continuous steam release to keep oil running into the cylinders, engineers may keep the throttle poked a bit when stopped, or braking for that reason so you could still have some steam tweaking thru the superheaters.
Either way get the engine down for repairs ASAP.

"There was enough water that I could not keep the far left corner burning."

YOU HAVE A VERY SERIOUS AND POTENTIALLY LIFE THREATENING SITUATION ON YOUR HANDS.

THIS ENGINE NEEDS TO BE TAKEN OUT OF SERVICE IMMEDIATELY !!!!!!!!!!!!!!!!!

THIS ENGINE NEEDS TO BE TAKEN OFFLINE RIGHT NOW. OPEN THE GRATES AND DUMP THE FIRE. DO NOT BANK THE FIRE, KILL THE FIRE COMPLETELY...

THE PRESSURE IN THE BOILER COULD BE RELEASED AT ANYTIME (EVEN IF YOU ARE NOT OPERATING THE LOCOMOTIVE) WITH VERY BAD RESULTS....

MAYBE YOU SHOULD CONSULT YOUR LOCAL EMERGENCY SERVICES PERSONNEL ?

LET IT COOL SLOWLY, USE THE BLOWDOWN VALVE TO RELEASE PRESSURE IN INCREMENTS (every 10 minutes or so) UNTIL IT HAS COOLED DOWN TO NORMAL ROOM TEMPERATURE. YOU DO NOT WANT TO CREATE ANY THERMAL SHOCK WHILE THE BOILER IS STILL PRESSURIZED.

Sorry for the yelling, but you have in your possession a literal BOMB....

And it does not have to be at full pressure to cause extensive damage, a 50 psi steam boiler explosion can still be quite fatal. You need to get this boiler cold as quickly and safely as possible.

A few small leaks (a little drip drip drip) when the boiler is cold is acceptable, normally they will seal up as the metal warms.

If you have enough water exiting the pressure vessel and/or associated piping, superheater tubes, etc. to affect your ability to keep the fire burning YOU HAVE A VERY SERIOUS PROBLEM....

As another poster said;

"You are poking a dragon now, and when (not if) he wakes up, it won't be pretty."

I agree completely.....

Fix it right while you are still alive to do so.

Be safe, respectfully, Kevin.

Last post is the best post here.

This is how accidents happen. Do the wise thing, take the engine down, and fix it right..