Your seal vendor should be able to advise both the axial thrust on the seal sleeve, as well as the starting and running torque requirements of the seal.
Suggest you ask them.
Good luck
Frankly, I am really not sure what the point of a 4 hour run test would be. Generally, most folks are happy with a run until oil temp stabilizes - after that point, not too much changes anyway.
as the throat area increases, the BEP of the pump moves further out, and the curve flattens.
It is pretty much direct - if the throat area increases by 10%, the pump BEP moves out 10% - at some point, the impeller will end up limiting.
hmmm - If there really is a significant margin over NPSHA, then I'd suspect a really high suction specific speed, and eye re-circulation - ie, the impeller is operating well below design capacity.
It happens - CI impellers are very susceptible to the damage.
One last thought for you JJPelin.
Inline pumps have come a long way in the last 15 years, but still have not overcome the stigma of their poor past performace. Your comment about the great distance to the first "true" bearing is absolutely correct. That's why pretty much all the vertical...
I believe a lot of the older United inline pumps have a poor mechanical design that starts with the coupling to shaft interface. That may be the root problem here. Have you ever tried to contact the manufacturer for upgrades?
Just as a curiosity, can you advise what the original seal and flush...
adding to bingopin, perhaps the hidden flow path could even be a missing or damaged wear ring.
I'm not on sure footing here, however, I would expect some very serious motor issues if one of the phases shut down - probably leading quickly to a motor failure - any thoughts?
I would start the...
wow - lot's of good stuff here.
A couple of comments to add to the mix.
Going back to the original question, I would suggest that there is nothing wrong with a single volute pump, provided the mechanical design of the bearing housing assembly is based on the single volute. It probably won't...
If you haven't purchased the driver yet, I would be inclined to look at motor efficiency. You may find the 1750 hp unit operating at 85% loading may be a long term cost saving. Just a thought.
