I am sorry for not getting the data for you to look at. I have to go at this gingerly.
I am beginning to lean on simply, impingement attack due to alot of bubbles in the sea water. The galvanic aspect of this wear simply does not connect, mainly because of no other evidence, for example...
Thank you once again for all your replies. I unfortunately have not had the time to give you other specifics such as the NPSH.
I will tell you though, that these ships operate in the Caribbean where usually always you have clear clean water. Of course the biggest headache is in port...
Thanks for all the interesting aspects.....
Here is what we know.. At least 2 or 3 sets of coupling bolts have broken over the course of about three years on a 186 kW motor driving a vertical centrifugal pump. After is was determined??? that that bolts were insufficeint, they were replaced...
On a 200 HP electrical motor driving a vertical centrifugal pump how important is determining an electrical center when spacing and setting the coupling?
Seems we are shearing alot of coupling bolts and we do not know why.....
Thanks for your comments....
This damage is occuring on a certain class of vessels of which all of the sea water pumps were showing these signs of wear... as a lay marine engineer I felt it was solely a cavitatioal process however others contributed a galvanic corrosion going on.... one of the...
What comes first... We have a set of shipboard pumps which are in my opinion showing pitting similar to cavitation on the inlet vanes of the impellors. Some camps claim that due to galvanic action or electrolysis has caused this wear by first knocking off the oxide layer then accelerating...
