Do anyone experience in titanium conderser tube removal?

[TAGE]

Dear All
I have reached to the dead end of my decision with the main contractor for Power plant construction. I have a major problem of tube removal due to limited space. Our contractor said that their titanium tubes were not required to be removed for maintenance so they did not provide a space for accessibility!!!! How come? So my question is do anyone has experienced in this problem in case there is NO any problem of the plant operation..
Please share me your experience of what kind of occurences that you have to remove tubes urgently. and it would be really appreciated if you provided the concrete evidences for my reference...
Thank you so much indeed.

Best Regards

 

[StoneCold]

Generally tube removal is based on performance. Is the performance of your unit suffering so you feel that you want to remove the titanium tubes? Are they in an exchanger bundle or are the main fired heater tubes made of titanium?
Is it just for tube inspection?
I need more information to help you.

StoneCold

 

[rmw]

Nothing is absolute and nothing is forever. While Ti tubes are fairly 'bullet proof', they are not fool proof, and the day might come that they, or even the whole condenser tube bundle might have to be removed.

Insist on a tube pull pit regardless of his assurances.

rmw

 

[EdStainless]

pulling is easy. I have seen it done with only a few feet of clearance.
How will you get the water box covers out?
How will you get new tubes in?

As tubes are pulled they are flattened and chopped into short pieces.
Of course I hope that you never need to remove any for trouble shooting/failure analysis.

I can imagine the need for water box maint.

= = = = = = = = = = = = = = = = = = = =
Corrosion, every where, all the time.
Manage it or it will manage you.

http://www.trent-tube.com/contact/Tech_Assist.cfm

 

[TAGE]

StoneCold! Yes you're right!sometimes is a performance issue and they are an exchanger bundle (answer your questions).

EdStainless, understand your explanation, but our main contractor further pointed out their the method of condenser tube removal if we wanted to. The method was really too complicated to do in my opinion. Due to their design of small space of a turbine hall, we have to CUT some portions of electrical power lines (the three bus duct lines) connecting between a generator and transformer crossed over waterbox and Cooling water line (inlet) in order to open the waterbox and access overhead crane to this pulling area!!! then moving them to the allocated laydown area. After we finish the maintenace work, we must reinstall the three electrical lines by welding ourselves!! It is really impossible for maintenance staffs......
That was my problem,and the contractor did not want to change any equipment arrangement in their design.They claimed that it was in-house design, can not to change but I don't think so..

Further queries, please let me know

Regards

 

[metengr]

TAGE;
I am going to ask the obvious question - who is the customer? The contractor's explanation of not having to worry about replacing Ti condenser tubes is a ridiculous argument, and is probably using this argument to avoid added construction expense. You should be demanding that the contractor either provide you suitable accessibility for removing and installing replacement condenser tubes or find another contractor who will follow your recommendation.

I have heard from several of my esteemed colleagues in the Power industry the potentially serious problem with using Ti tubes in a condenser that was not properly designed (tube support spacing and staking of tubes) to accommodate this material.

 

[kenvlach]

Titanium sometimes fails in ~lifetime applications due to improper fabrication.
My application was different, but a bit analogous in principle.
The low bid fabricator did things their own way (didn't consider the solution very aggressive, didn't stress relieve & passivate after bending up a serpentine-style immersion HXer).
Result: SCC on every outside bend (180[sup]o[/sup] bends).

So, heed the previous responses.
Suggest also having an independent professional power plant designer & your head of maintenance go over the plant design, as other problems are likely to arise due to contractor scrimping. Maybe expensive to fix now, but worse later.