What flow/head is the pump running at? It looks like an OH5 style pump, so the motor bearings are carrying all the thrust loads of the pump. I'd say that the higher speed is overloading the motor bearings.
Is this a vertical or horizontal pump?
NRR (non reverse ratchets) are pretty standard on vertical pumps with hollow shaft motors. They are extremely rare on horizontal pumps, I remember one customer wanting to investigate such a thing about 5 years ago, I wasted about four days trying to find...
Do you mean what we call the hydraulic coverage / envelope curves, showing the range of capabilities for various sizes? Like this? To be honest, I don't know how I would do it but probably in excel and then figure out how to do them as envelopes.
When you say the flow is reduced to 13m3/h to reduce vibrations, does this mean you were trying it at a higher flow rate, or is this where you run it on salt water? The pump is designed for 100, and you're running at less than 15% of that. You can expect high vibrations and short bearing and...
This definitely looks like a LF application, so I'm not surprised by the efficiency. What you are trading off is that the efficiency is low, but the shaft stresses are also low, so the reliability will be higher.
I'm assuming that the site requirements for an API pump for HC condensate are the...
That was a point that our profs in engineering school made repeatedly. You have to understand the result you are looking for, and what the numbers mean. If it's friction loss for a variable flow rate, then the 10% or 1% factor is likely meaningless. Learn to estimate and round as appropriate...
An efficiency that low implies to me that you're looking at a 'low flow' pump. Some centrifugal pumps have straight radial vanes, like 24 of them, and are capable of very low flow rates, like 1 gpm. Although the efficiency is low, the hp is also low, so the actual amount of power lost to...
Here is one source, scroll down a bit, and read the commentary.
https://www.katmarsoftware.com/articles/pipe-fitting-equivalent-length.htm#:~:text=We%20can%20do%20this%20if,with%20its%20own%20Equivalent%20Length.
3. Equivalent Length Values for Reducers (Turbulent Flow Only)
The pressure drop...
If memory serves me, many of the Goulds slurry pumps have 1045 shafts with 4340 as the 'high strength' option. How this relates to your situation, nobody knows. It's simply one data point in the universe of possibilities.
I believe (and I stand to be corrected) that it is the same impeller/casing as what they call the MegaCPK, so the attached are the 50Hz and 60Hz curves. However, do your due diligence to confirm, or just use this as rough guideline, as it's unlikely that the performance would be radically...
There is a thread ON HERE about this topic:
https://www.eng-tips.com/threads/nfpa-20-dedication-of-fire-pumps.422637/
"
Note: I found this paragraph from NFPA 20 - 2016 Edition, but no restrictions!!!
4.7 Pumps, Drivers, and Controllers.
4.7.1* Fire pumps shall be dedicated to and listed for...
As Dynamics Eng has pointed out, API610 is your guide.
Since you refer to it as a BB3 pump, that implies API610 is your reference, so I suggest you read it, as it tells you exactly what to do.
Also, please specify if any codes apply. Does it need to be UL/FM approved? I've dealt with fire pumps that did need FM/UL, but also many that did not. That should be the first thing you specify.
Somewhere in my library of books, I believe I have an old Canadian Code for Wood Framed Structures; if you can search up a copy, it will answer all of your questions, and many that you did not know to ask.
The fact that B is the furthest from the deaerator is very suspicious. Remember that the only NPSH you will have is the elevation from the pump centerline to the level in the deaerator, it is very suspicious that B is being starved, as it is furthest from the DA.
I have never heard of an API stamp for a pump. Manufacturers will build pumps to API standards as noted in their literature. Can you explain more clearly? Are you a customer or potential manufacturer?
If it's always the pump in B position, and you replaced it with a new unit and the same thing occurred, it's an indication that it may not be the pump, it's a piping or operating issue. Verify operation of all valves, check valves, etc.
A google search brings up this being sold by an SKF dealer:
51134 M/DH
51134 M/DH 51134M/DH THRUST BALL BEARING ; DUAL HOUSING WASHER
Thrust Ball Bearing; 170MM Bore 1; 172MM Bore 2; 215MM Outer Diameter; 34MM Height; Single Direction; Not Banded; Brass Cage; ABEC 1 | ISO P0 Precision
