See link (Pg. 2 - KRT Wet Well / Dry Well): http://www.ksb.com/linkableblob/ksb-us/983434-256524/data/USA_Pumps_Mixers_Production_Brochure-data.pdf
I am talking only to single stage submersible pumps.
Any additional information?? i.e. advantage of low liquid levels, vibration, seal life, etc.
Can someone explain the operational/design advantages/disadvantages of horizontal (OH1 style) submersible pumps when compared to typical well-type vertical submersible pumps?
Fluid Characteristics (gas content, solids, temperature), Reliability. I agree with DubMac in that there are more twin-screw installations. You could ask an OEM and ask them to avoid the sales pitch for pros and cons. Bornemann is pretty good, so is Leistritz
Alng the same line as Artisi,
Who is the pump OEM? Ask them for the pump curve to the impeller diameter you just cut it to. They will need the material, speed, model, diameter and pump size. if you have all this, it should take them 5 min. to get back.
First thing to look at would be changing out the bearings. If the problem persists (i lean with LittleInch), there may be electrical and mechanical harmonics (resonance) being generated by the use of a new VFD.
I know that motor manufacturers typically prefer one VFD mfg over another for this...
i would also recommend a metallic disk pack coupling.
one other consideration is to determine if the coupling is sized properly i.e. HP/RPM. At lower speeds the coupling may be undersized and not rated for that speed of operation. you may need to resize your coupling. Also, check your coupling...
50HP and greater - i would stay away from c-face (close coupled) motors.
in terms of lubrication - i would go with flood oil if you have a good maintenance crew; otherwise go with grease.
depends on a lot - especially the quality/capability of your maintenance dept.
here are some high level descriptions:
1. takes a bronze ring and "flings" oil around the shaft to lubricate bearings (this is the industry standard)
2. requires oil mist system ($$). best bearing...
I would take a look at a BB2 if you done have a preference for a BB1.
Curves attached (on the second curve the correction factors are listed in the top right).
Again, contact an OEM - they will be glad to...
VS4 is the economical choice between a PC and centrifugal.
Also based on your last application descrition, it seems that this pump would only be handling runoff. Again. VS4 should be fine 99.9% of the time even with some solids.
If this is crude oil and not machine oil, id watch for H2S...
gibson -
not to get into a battle - you sound knowledgeable. I am sure you can agree that there are instances where the min. flow of the system can be lower than the min. flow of the pump. I can name a number of them if you want to dispute it.
hence the process vs. pump perspectives.
regards.
gibson -
you are speaking from a process perspective - i am talking from a pump perspective.
Determine and min flow of the system ----> see if that is feasible with the current pump ------> if not, buy new pump.
mpeck -
Ill remind you the point of this post was to determine the minimum speed. based on your description above, after numerous posts and discussions, it is clear that the minimum RPM is not the question, it is the minimum flow of the pump. This entirely has to do with flow and NOT...