Turbine Overhaul 5

[yulinios]

Hi There
I would like to about ¨guides for steam turbine overhaul¨, could you advise me plz.
Bye

 

[rmw]

Where to begin???

Seals, check interstage seals; shaft packing, spill strips, etc., and replace or retooth as necessary. Bring all back to original OEM clearances.

Blade erosion, rotating, and stationary blading. Specialists will have to bring nozzle and stationary stage blading back to original contours using welding and blending techniques.

Cracking. Shafts, rotating blading, tip tennons, etc., all rotating parts will have to be checked for cracking by a variety of means, depending on how detailed you want to get. Shell bolting should be checked for cracking. It can be as simple as visual, or as technical as magnaflux or dye penetrant.

Nozzle block erosion/first stage blading erosion. This is usually a high wear area needing remedial attention.

Last stage(s) blading (bucket) erosion. Some have erosion shields. Check condition, and correct as needed.

Valving. Stop and control valves must be checked for stem and shaft cracking, as well as bushing and packing clearances.

Bearings need to be checked for excessive wear, and corrected if found to be out of tolerance.

Oil lines need to be checked, cleaned, and possibly flushed.

This should be enough to get a little conversation started. If more comes to mind, I will return and repost.

rmw

 

[andyenergy]

A bit of an open ended question.

rmw has most of the areas sorted there. Most organisations operating steam turbines have some sort of maintenance plan for steam turbines or rely on the services of a specialist contractor to carry out the work.

If you're developing a plan yourself the items mentioned by rmw are good but they need to be planned in at sensible intervals.

For general advice on overhauls that's fairly accessible, it's hard to beat

http://www.epri.com

They have several documents on turbine overhaul but you have to be a member and it costs....

good summaries iof typical programmes:

http://www.epri.com/programHigh.asp?program=249630&objid=286429

http://www.epri.com/journal/details.asp?doctype=products&id=510&flag=archive

(No I don't work for EPRI)

This link shows basic practices of a contractor.

http://www.thomasonmech.com/toc.htm

I found courses available in the US:

http://www.hpcnet.com/course_info/certification/steam/maintenance_technician.html

Type steam turbine maintenance program into Google and spend a few hours clicking on links.

Hopem this is useful

 

[byrdj]

The "main" reason for outage is economics, "restore the steam path efficeincy". New turbines and components are sold promoting thier designed will lenghten the inspection interval purely becasue efficency remains high for longer (up to seven years!). If efficency remains high, why have outage?

reliablity reasons would be to inspect stressed components that are subject to fatigue and breaking. Try to identify and repair before forced outage occurs between inspection interval.

Safety reasons would be to ensure valve operation by removing deposits that cause interferance.

 

[rmw]

Here is a place that you can find some reading regarding factors that affect steam turbines.

http://www.gepower.com/prod_serv/products/tech_docs/en/all_gers.htm

This is good information from a conceptual point of view.

I did not recommend any particular GER, as I thought you might enjoy perusing what is there.

rmw

 

[andyenergy]

great link rmw!!

 

[yulinios]

Hi everybody
There are a nices sites, valuables answers, thank you!!
Bye There

 

[andyenergy]

yulinios -

Just came across this site while looking for something else - this could be useful also.

http://www.mhi.co.jp/power/e_power/support/index.html

http://www.mhi.co.jp/ydmw/power/turbine/index_e.htm

Hope you like them!!

 

[rmw]

andyenergy,

WOW!!

rmw