Tagged With "GT"

Topic

Gas turbine - Compressor blade damage

adisorn sri ·
Who have some problem same us? We used gas turbine model V94.3A. On 1st MO'2015, we found damage on compressor blade. Moving blade stage 7 fracture 3 EA. Its become FOD and damage to other stage. For RCA It's start the problem with tip blade...
Topic

GT SGT600 PT bearings 3 & 4 High Vibration

Hisham4ever ·
Dears, We have experienced dramatic change of vibration over GT24 "SGT600"  where bearing 3, 4. We have stopped the unit and start it again and vibration trend still high, specially bearing 3. We also carried out NDT test on PT coupling shaft but found no trails for cracks! The high vibration parts are shown in following schematic:     the attached files contains all the required data. any suggestions about this?? it will be appreciated   
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Re: GT SGT600 PT bearings 3 & 4 High Vibration

chitrang.nanavati ·
Hi Hisham, Can you provide the spectrum of bearing 3 ? At what frequency vibrations are coming What is the history of this bearing, can you trend the vibration over 4 months ?
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Re: GT SGT600 PT bearings 3 & 4 High Vibration

Hisham4ever ·
Dear chitrang.nanavati, Thank you for your reply & sorry for the delay, I have attached the spectrum trends for for Bearings 3 & 4. thank you again.
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Re: GT SGT600 PT bearings 3 & 4 High Vibration

Hisham4ever ·
Update: the attached file is SEIMENS reply on this regard.
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Re: GT SGT600 PT bearings 3 & 4 High Vibration

Walt Strong ·
The report by Siemens offers a hypothesis that the vibration changes with load and torque. They recommended an inspection of the shaft couplings. You have already done an external visual inspection that did not reveal anything significant with the disk packs. The vibration phase angle data does not change that much with changing load, indicating that the apparent unbalance phase angle remains the same while unbalance increases. The spool piece part of the coupling would have to be shifting...
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Re: GT SGT600 PT bearings 3 & 4 High Vibration

Hisham4ever ·
Dear Walt, thank you for your reply, I have contacted the Mechanical department for your inquiries. They have already visually inspected the gearbox, nothing have been found, also the vibration on the gearbox seems quite normal over the loading scale. Regarding the bearings: they haven't conducted any test except lowering the Lub oil supply pressure from 200 kpa to 170 kpa which showed no effect on bearings 3 & 4 vibrations. Beaering types: Bearing 3 : Journal Bearing 4: combined thrust...
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Re: GT SGT600 PT bearings 3 & 4 High Vibration

bkarim ·
Dear Hisham4ever ; I’m not familiar with Siemens GT, I’m more GE HDGT (General Electric Heavy Duty Gas Turbine)… What’s happened on June 2014? What did you find after the feeder trip ? And what was the relation between the FEEDER TRIP and the high vibration on #3 and #4 bearings?? On HDGT when TRIP occurs, automatically the auxiliary lube oil pump starts time to cooldown the machine rotors and theirs bearings. If , for any raison like electrical power cut, the auxiliary pump doesn’t work,...
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Re: Gas turbine - Compressor blade damage

candy ·
What caused the rubbing?
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Re: Gas turbine - Compressor blade damage

adisorn sri ·
In this case, we test micro structure of blade we found some micro crack on blades tip start point of fracture and found vibration phase change after HGPI. and talk with OEM.>> rubbing is cause of fracture. But, a cause of rubbing, we're finding together with OEM. In normal case of rubbing is show in compressor blade clearance and rotor position but in this case compressor blade clearance and rotor position is not problem, it's on criteria. OEM find RCA around 3 month. Now we don't know.
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Re: Gas Turbine Bearing Failure - Lube Oil Leakage Caught Fire

Rizwan Ahmad ·
The pic of failed bearing #3 is also attached.
Topic

Gas Turbine Bearing Failure - Lube Oil Leakage Caught Fire

Rizwan Ahmad ·
The machine is Turbo Generator , the Gas turbine is GE Frame 1. Fire incident happened in GT side due to Lube Oil leakage either internal or external not confirmed yet. Upon inspection , the Babbitt material loss found in bearing#3 (see attached crossection ) at LP rotor. Also coke or tar found at LP bucket. All relevant pics and GT crossection dwg attached . The questions are: 1) what’s the origin of lube oil leakage external or internal ? Is it split from bearing housing or lube oil supply...
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Re: Gas Turbine Bearing Failure - Lube Oil Leakage Caught Fire

Rizwan Ahmad ·
Re: Gas Turbine Bearing Failure - Lube Oil Leakage Caught Fire
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Re: Gas Turbine Bearing Failure - Lube Oil Leakage Caught Fire

Ngo Dinh ·
I do not have experience on frame 1 but I think you should check some information and answer for yourself that: 1. The leakage oil just happen at Bearing #3 or at all bearings? 2. Have you checked the oil drain piping for any plug/stuck? 3. there is buffer air supplied to labyrinth seal, isn't it? if any, have you checked the buffer air lines? 4. How about oil vapour system? 5. Have you checked the bearing temp? when is it increased? the same for vibration? If the fire happen in the moment...
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Re: Gas Turbine Bearing Failure - Lube Oil Leakage Caught Fire

Rizwan Ahmad ·
The Ventilation Fan was also tripped due to breakage of its belt which may increase the T of enclosure and which further melt the Babbitt white metal which leads to bearing failure ?? I am not sure, can u recognize from bearing pic, is it melted during running or stationary? or is it melted due to high LO temp??? I am not sure
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Re: Gas Turbine Bearing Failure - Lube Oil Leakage Caught Fire

Rizwan Ahmad ·
During inspection, the brass oil seal was found damaged. So, there is a possibility the oil could leak from Brg#4 and got fire, but question is why Bearing#4 which is near to fire location is not melted and how the fire traveled from Brg#4 towards Brg#3 ? You know its Turbine Section , the pressure at Brg#3 is higher than the pressure at Brg#4
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Re: Gas Turbine Bearing Failure - Lube Oil Leakage Caught Fire

Ngo Dinh ·
It is possible that the shaft is been hot due to fire and make the babbit overheat like picture. You should take event sequence and see what happen near the event time. Focus to oil system and clearance, i think you will get your answer.
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Re: GT SGT600 PT bearings 3 & 4 High Vibration

aziz58 ·
Dear walt I am sorry about that. I have search for sgt turbine and find your comment at this post. Because i couldnt send private message to you. I apologize again . Best regards
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Re: GT SGT600 PT bearings 3 & 4 High Vibration

Walt Strong ·
It is not professional to hijack other postings to draw attention to your posting. The best way to get attention is to add information to your posting. A large font and the request to search for your original posting is not going to improve your chance for help from me or anyone else. Walt
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Re: GT SGT600 PT bearings 3 & 4 High Vibration

aziz58 ·
Re: GT SGT600 PT bearings 3 & 4 High Vibration
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Re: GT SGT600 PT bearings 3 & 4 High Vibration

OLI ·
I would look further at the coupling as OEM suggest they would have seen it before, another thing to look at that may not be so complicated would be the mounting of the end of the machine. If you had a none standard shutdown so parts that normally can move got stuck some way or have increased friction to move may create problems.
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