Balancing Impeller Only.....Risky?
Balancing Impeller Only.....Risky?
(OP)
Purchasing a 3"x1-1/2"x11" (OP: 155 gpm @ 320ft)centrifugal pump/motor ass'y. Manufacturer wants me to accept them balancing the impeller only. I asked for the whole assembly to be balanced; shaft, rotor, bearings, etc.
A) Why is that such a difficult request? Am I being overly cautious?
B) What is the real risk of just having the impeller balanced since it is the major part of the off balance inertia risk? Probability of the whole thing shaking apart at the seams?
Pumps are not my forte so any help you can provide is appreciated.
A) Why is that such a difficult request? Am I being overly cautious?
B) What is the real risk of just having the impeller balanced since it is the major part of the off balance inertia risk? Probability of the whole thing shaking apart at the seams?
Pumps are not my forte so any help you can provide is appreciated.
Frank "Grimey" Grimes
You can only trust statistics 90% of the time.





RE: Balancing Impeller Only.....Risky?
good luck!
-pmover
RE: Balancing Impeller Only.....Risky?
With the current balancing practices used in the Industry, they are well proved to be be reliable and not a hinderance to reliability.
RE: Balancing Impeller Only.....Risky?
RE: Balancing Impeller Only.....Risky?
In my 20 yrs experience, on a pump this size, balancing the impeller only is enough; ask for G2.5, and you're good to go. We have many plants here who are extremely fussy about vibration levels, and all overhung pumps are balanced impellers only. It's simply not practical to do it any other way. Shafts are so well made now, you'd be extremely unusual if you had a problem. (Assuming, of course, that you're talking of a mainstream, reputable manufacturer).
RE: Balancing Impeller Only.....Risky?
Thank-you.
The manuf. is Hayward Gordon, I believe them to be a reputable comany with a long history. It is indeed of the overhung variety.
Impeller balancing alone, is what I will accept.
Could you take a look at this thread?
thread407-175883
Is ANSI/HI 1.6-2003 the new "standard" in pump testing?
Frank "Grimey" Grimes
You can only trust statistics 90% of the time.
RE: Balancing Impeller Only.....Risky?