Caution... Trapeze artist's at work (ME)

EBEBRATT-Ed

Mark

Nice job and good planning. Not to critisize but looking at the come a longs pulling on the short chains to the coils-it would be better to use two short chains with a shackle on the come a long hook and so that the chains are secured to the shackle.

The way it is rigged the come a long hook could act as a pulley and if the loald shifted it could roll to one side and tip over.

I know i'm being picky and it's not likley to roll with a balanced load like you have but it can happen.


ED

[Deleted User]

The heavy work is done....

The boiler heat exchanger job from hell is almost history thanks to the skills of my fantastic A team :-)

The job went just as easy as it did in my first 100 dreams...of the same job.

Thanks to Tim Reini for his most excellent prep work and rigging installation, the HXer on the worst case scenario boiler slipped right our of its holster, made the turn and came to rest on the floor in perfect fashion. 1,000 pounds of copper and steel floating in mid air, and being moved with a push of the hand. As Scott woud say, "Like BUTTAH!"

About the only hang up on the whole job was when we tried to turn the corner withthe HXer on 4 wheel dollies to get it out of the boiler room. Had to stand the HXer up on its side to get it through the double doors. No sweat for these guys though.

We no sooner got the old one out when like clock work, the new one showed up. Kudos to John Schneiter of WSI and Charles for making it all work. Schneito actually brought the new one in his personal low rider truck becasue he was worried about snagging a fire protection line or drain line with a company vehicles heighth in the parking garage on your way to boiler heaven.

Once there, we partially off loaded it into Seans truck, then used camper jacks to clear both trucks, pulled both trucks out from underneath and then lowered it to the ground, and placed them on dollies for the trip in. The new one slipped in just about as easy as the old one slid out, including the arial 90 degree turn.

I had to run and do some errands, and by the time I got back, these guys had extracated the second heat exchanger and were lowering it to the ground.

Tomorrow they go back and put the finishing touches on the sheet metal jackets, lower the 36" B Vent onto the hoods, and buckle things down in general.

Thanks for all your hard work guys! It was a pleasure working with you all today, as it is every day.

ME

Weezbo

That is a Good Thing*~/:)

i got to run a few errors today too:) it sure helps when the guys are reliable and work with:)

S Ebels

Mark

What kind of a load were/are these things connected to. Are these the HX's that froze a while back?

Beer? Heck, if those baby's are copper, you probably have champagne money.

Jobs like that require a TON of preplanning and thought. I've always wondered how I could bill for the time I spend lying in bed thinking about some of the more demanding things we do. Even my dreams are inhabited by burners and boilers.

Cosmo_3

Looks like you were dangerously close to needing some fitter's crack Spackle on the job!

Hey, good planning, and execution!!! I always kind of thought that the nights I lie awake at night when a tough job like that looms the next morning must kind of be like a sports pro goes through the night before a championship game.....



Cosmo Valavanis

Dependable P.H.C. Inc.

Paul B._2

I'm curious as well,

Hi Mark,

It's a lot easier to put those HX's in on the assembly line with the overhead crane. Many Kudos to your crew for the efficient and professional manner with which they performed the work.

The refractory tile in those looks to be in excellent shape, usually if a heat exchanger fails due to low flow, or low entering water temperature the tiles show signs of sooting and overheating.

How many boilers are in that room, and how do they measure up (quite literally) to the code requirement for rooms large in comparison to the equipment?

Is there some other factor in play here? Negative pressure in the building? Not enough combustion air, causing chimney effect?

A failure of this type on the larger boilers is very rare, especially since the two usual suspects (low flow, and low entering temp.) appear to be absent.

Paul B.

[Deleted User]

Steve...

By loads, you mean the heating loads? It's a large apartment complex with FCU's throughout. I think this system was designed by Overkill Bill. The place recently went through another design condition cold snap and handled the loads just fine with only 2 boilers on line.


If you meant the physical weight load, each heat exchanger weighed in at around 800 lbs. Each trolley is capable of handling 500 pounds, and the double strut is the same. The comealongs are dead load rated at 1,000 pounds each. As the guys were ratcheting them up and down, occasionally the cable would roll on the spool, and make my sphincter do the momba. I made darned sure that there was nothing between the HXers and the ground but air.

Right before we started the job of hoisting them into the air, I had the guys raise the HXer an inch off the rack and JUMP on the Hxer to stress test all components. Everything held fine. I had nightmares the night before of the cast header splitting and coming completely apart with the HXer falling into the boiler, hence the stress test. Can't be TOO safe.

The boilers are Teledyne Laars HH5000, 5,000,000 btuH in Los Angeles...

The reason they froze is because the mechanical room is relatively unheated, and the physical plant SO MUCH overkill, that they weren't needed and didn't come on line. These are the ones that are piped P/S.

Hopefully tomorrow, we get approval to apply "freeze protection" kits to ALL the boilers.

I dropped by the job today, and my guys had everything 99% back together, sans a couple of missing gaskets which are being red labeled in tomorrow. Talked to the regional manager who was up here from Texas and told him of our status. He was hoping to be able to watch us perform the magic. I assured him we had photos.

ME

[Deleted User]

Cosmo...

That's my personal Mad Dog... And just like Matt, this kids got a heart of gold. Hard working, eager to learn, not afraid to jump in with both feet. We are a VERY lucky company to have the employees we have working for us. VERY lucky.

ME

[Deleted User]

Paul B...

Thanks for the kudos. I will pass them along to the approriate members of the team. I only plan these things out. Execution is the real test and key. The company made me sell all my tools to keep me tied to my design/estimation desk:-)

Prior to finalizing the job, I had my service tech perform a refractory inspection. He pulled enough burners so he could get a good overall view of the HXer'/refractory sections, and turned the water on to the boiler. There was no evidence of physical water errosion on the refractory. Good news for the owners. The tubes actually didn't burst. The headers froze and burst, and the water was pouring in right where the tubes enter the fire box. YOu can see the rust in one of the pictures. I was really suprised to see that the tubes were still intact. I would have thought that they would have frozen and burst long before the headers did. Just goes to show ya...

As for meeting code, there is adequate service room, per the I&OM. I don't think ANYONE ever expected to have to replace the cores on these puppies. Even I wouldn't have anticipated THAT need.

There are 4 HH 5000 boilers plus a couple of PW's doing DHW. If you look closely, you will see cinder blocks in the "breather holes" that were left in the walls. Also, the whole soffit is screened. There is MORE than enough combustion air for the attached loads. I talked to the management company about putting some motorized individual dampers in to serve the needs of the equipment, and they shirked at the price. With 36" B vent, I'm not 100% positive that THAT would even guarantee freeze protection.

When the maintenuts people blocked off the combustion air, I'm certain that the OFF LINE boilers 36" B vents became combustion air vents for the two firing boilers anyway...

The boiler are being controlled by a tekmar 8 stage controller. Each boiler is 2 stage non modulating.

ME

Constantin

Wow...

.... that is a lot of copper! I wonder if your local scrap dealer will think that you've developed a new business opportunity by removing the HX's from late-pay customers! :-P

Interesting mechanical room... consider how much room these people potentially had to play with, why cram so much heating capacity into so little space. Oh right, parking spaces are more important than servicability or a proper heat load calculation.

As usual, the prep you did paid off in spades. Looks like no-one is spending any time lifting the HX by hand, which is a good thing. I'm sure that many contractors would love the ability to strap a couple of I-beams to the ceiling and to use them as a guide to push sections into place when they have a knock-down to assemble.

Kudos, looks like you had a good time, no injuries, and made some money. I hope managament is smart enough to take you up on the freeze protection... Ditto for thr manufacturer.

[Deleted User]

Interesting discovery...

Tim and myself were recommissioning the rebuilt boilers today. One of them had their pump motor removed,and we had to reinstall and re-wire it. Got to looking at the wiring on the motor, and realized that it was wired for high voltage (460 V), and was being supplied with low voltage (215 V). I thought "What the..." Went over to the next boiler which was and has been firing, pulled its wiring cover and discovered that it and EVERY FREAKING PUMP IN THE MECHANICAL ROOM (7 in total) WAS MIS WIRED...

No WONDER they kept chewing up electric motors on the boilers. These 2 HP tri volt, triple phase motors are not CHEAP either.

Even the 5 HP main circulators were improperly wired, and they have been running since initial commisioning, 5 years ago.

How can that be? In checking with an electric motor rebuilder, he said IF the mechanical load WERE extremely light, it was possible that the motors could have lasted 5 years under those conditions. He also cautioned me that re-wiring them into their correct position COULD cause immediate motor failure. How right he was.... Let the smoke out of one that had already been rebuilt.

Somewhere out there, there is an electrician whose ears must be ringing off the hook. I suspect the owner of the building WILL find this gent and file a claim against his insurance, or worse.

I think we gained a customer for life after this affair...

Proceed with caution, and NEVER assume that the person who installed and commissioned the equipment knew what they were doing... NEVER!

ME

Constantin

Hear Hear!

I'm discovering the same thing here. The worst part about it is knowing that 99% of the things were done right, but that 1% is lurking in there... and depending on what the 1% is, it can be serious or trivial to fix.