hello all!
Can a high clearance between the shaft and the shaft hub lead to high vibration levels? And does it appear in the espectrum as 1x only ?
thank you in advance!
When the two shafts are not aligned, it's quite common to see the n and its harmonics, mainly 2n and 3n frequencies in the spectrum.
Take a look at this simple article here:
http://www.plantservices.com/articles/2014/vibration-analysis-detect-alignment-problems/
I must agree with you when you say (P1-P2) = Diff. Pressure or Pressure Loss
I don't see why these two definitions would be different.
Static pressure is defined as the pressure measured by pressure gauges. The Total pressure is the sum of Static pressure and the velocity pressure.
But in the...
I see your point EdStainless. I've studied more the issue and I think letting the rubber lips run over a shaft sleeve will be the best and cheapest solution. And at any time the sleeve gets worn out it can be replaceable.
Thank you
Hello All
Let's suppose I've got in hands the pump theoretical curve (given by the Euler equation) and the efficiency pump curve. Can I estimate the real pump curve simply by multiplying the theoretical curve by the efficiency at any flow point?
Thank you in advance
There are no suspended solids in the system. It's simply water.
Perhaps a hard sleeve o-ringed might solve the problem, and it´s a pretty simple solution.
Another solution I've been thinking about is nitriding the shaft surface. So the hardness increases and the excessive wearing stops.
Hello!
The company I work designs water pumps. The water (usually at 104 ºF) is sealed by a rubber sealing.
The problem is that within short amounts of time of running the shaft gets worn by the action of the rubber lips.
The shaft material is AISI 304. I think it's not hard enough to...
Sidebands indicates amplitude modulation, and by the spectrums you attached here, it seems that the frequency modulating the harmonics is abtou 250 CPM, which appears with a little peak on all the spectrum. The point is to find out what problem is generating this frequency.
But by taking all...
Hello,
Here in my company we design and manufacture small pumps, among other equipments.
But we're having troubles with the pump sealing. After one year of running, the fluid (usually water - 86°F) starts to leak through the rubber seal. After disassembling the pump to fix the problem, we find...
first thing to do is to determine the specific speed, so you can select the best pump to your application.
Here you can find how to calculate that: http://www.engineeringtoolbox.com/specific-speed-pump-fan-d_637.html
Hello,
Here in my company we design and manufacture small pumps, among other equipments.
But we're having troubles with the pump sealing. After one year of running, the fluid (usually water - 86°F) starts to leak through the rubber seal. After disassembling the pump to fix the problem, we find...
Hello, justomi
let me ask a few questions first. How excaclty do you measure the TDH? Are there pressure gauges? I'm asking that because I didnt notice them at your sketch.
By raising the pump, you end up changing the pump line geometry, and hence you cannot calculate the head loss at suction...