Replacing Surface Condenser Tubes

[franklin55]

We have a surface condenser for a steam turbine being in operation for the last 07 years. Now its tubes have started leaking. The No. of leaky tubes have exceeded the maximum number that are allowed to be blinded. We have now two options with us:
1. Replacing the whole equipment with a new one (costly option)
2. Replacing half of the tubes in Annual maintenance shutdown this year and the remaining half number in the next turn around.

the total number of tubes is 4000. there are 8 baffles in the condenser and 8 m is the tube length. The shutdown duration is around 25 days.
Can anyone advise: which option is the better one..keeping in view the replacement cost and the time required for replacement in both the cases.

 

[SnTMan]

franklin55, we had some re-tubes a while back, we used a contractor who had some special equipment. As I recall they had air hammer tooling to start the tube, after which they fed it thru a roller extractor which also chopped the tube into about 3 ft. pieces which they binned.

Might be able to find the contractor info if interested.

Regards,

Mike

 

[unclesyd]

Did you watch the videos of the puller, traveler, and chopper on the Condenser and Boiler Tube web site?

I've used all of the above tools and procedures along with the method posted SnTManon heavier wall tubes. If as you state time is very important you will want to use any tools available.
You have to remember that retubing, the installation of the new tubes can far exceed the removal time.

One other question is what type of plugs were used for plugging the leakers?

 

[franklin55]

Only tapered metallic plugs without welding were used.

 

[unclesyd]

Depending on how hard they were set you may loose some tube holes. Normally if your intentions are reusing the tubesheet one would use a ring and pin, or a condenser plug to mitigate any possible damage to the tubesheet and any problems installing the new tubes.

http://www.tubeplug.com/index.html

 

[rmw]

Í've seen cases where drilling and extracting the plugs took just about as long as the rest of the detubing process.

Here is another site to root around on. They used to have a fantastic video of a tube puller/chopper.

http://www.retubeco.com/

They certainly have some great photos, but most of what I saw was way bigger than what you have (same range as what I alluded to in an earlier post.)

I'll leave it to you to root around and glean what you can use from the site. Lots of good stuff there.

rmw