Skip to main content

Read our primer articles on Oil Analysis and Tribology

Recently our steam turbine was tripped due to over thrust bearing position. When do the oil sampling, we have found that our turbine oil have high water level content..other than that also some white metal that coming from thrust bearing that had rubbing..what became my concern is where do the water can be ingress?? is anyone can give any idea?
Original Post

Replies sorted oldest to newest

Water ingress can come from many sources and steam turbines are bad about water in oil just because it is a steam turbine. Filtration systems are used worldwide to remove the water from the oil. Turbine oils are designed to help in the water removal.

In-gress can come from environment; oil coolers that use water, the process steam can even put water in the oil.

We have a couple of steam turbine systems and unless the cooler starts leaking most of our water problem occurs after a downtime and before a startup. IF you do not have a filtration system that removes water that water stays in the oil a long time. Need to filter it out.
Dear Aidil

Other point of water ingression in Steam Turbines is Seals near bearings.

Sometimes whenthe seals don't work very well, some of steam goes to the bearings, and contaminates the oil.

On the other hand, if you have found metals, I would recommend a complete Flushing of the system (according to ASTM D-6439-05), and it would be a good idea, to installa a Oil Purifier for removing water of the system. This Oil Purifier will help to you in the future for avoiding non Programmed Shutdowns.

Best Regards,
Cristián Schmid.
aidil,

the normal cause of moisture ingression in steam turbine is due to excessive steam leak through the turbine end seals. your plant should have a portable centrifuge/purifier unit to address this issue since this is normal issue for steam turbine. yes, the ultimate solution is to replace the seal. routine moisture analysis should also there so that you will be able to determine the time the reservoir needs centrifuging.

a quick check you can do is to put a loose fabric tied to a stick and head it close to the space between bearing box and turbine end seals. if the movement is significant (better compare it with other healthy turbine), then you can fairly conclude the end seal clearance is off. you may get your operation to increase the opeaning of leak steam return line going to the condensor to reduce the leakage rate.

tripped on thrust may be due to other reason. do not jump to the oil quality first. do cover all angles..if the pump is pumping emulsified oil, the abnormality you will get to see first is the lube oil and control oil filter performance..
Thank you for the brief description of that. I'll look into the ideas that had been sharing from all of you..

Other than that issue, is there anyone had the ideas on turbine additives. How frequent we should do the RULER test to monitor our additives. Some additives maybe related to another additives that will effected when one of them had depleted.
Post
×
×
×
×
Link copied to your clipboard.
×