Counterweights and Vibration

First i would determine why its vibrating so much and address that. Then use vibration dampers to mount it in the container. If its vibrating that much that you in question about how to resolve it. It isn't doing the container any good or the blocks the container setting on.

the container is not setting totally on blocks.

blocks are pieces in some place under the conainer.

regards

I agree that you must try to address the vibration source, first of all. Reduce it, and be happy.

What you did when installing weights in the pump chassis is to alter the natural frequency and observed response in the pump as an overall assembly only. It does not mean that you reduced the efforts or reactions over the pump bearings... you may have increased it though...

After trying to solve the vibration source, I also agree that you must seat the pump on a support or chassis or maybe directly over vibration dampers/isolators, which will be seated over the concrete base. This way, you will be able to isolate the environment from the pump vibration, and allow the pump chassis proper travel not to be submitted to stresses in excess.

Do not forget to include also elastic joints in the pump inlet and outlet, because all that vibration may come and go through the pipes if rigidly mounted. This can also be a source of problems.

Mathematical analysis or calculation is probably futile as this sort of system is too complex with too many variables which are difficult or impossible to quantify...not to mention the unknowns...
That's what my previous post implied, but I was too lazy to express it lucidly.
Del

The pump with or without its container must be anchored directly from its chassis into a concrete/steel foundation, followed by good leveling.

"we have a high pressure pump has a high vibration because it is fixed inside container and the container is laied on concrete blocks..."

As pointed out by previous posts it is important not to take the high vibration for granted and just do fire fighting. As Dell has said it will be very difficult and time consuming to analyse what is happening, apart from that you would have to have the complete spec of the set-up to be able to evaluate as the vibration could come from multiple sources. First seek to find the cause of the high vibration, if it is from the pump and it is within the spec of the machine then you could consider whether to buy a better spec pump or to "put the hosepipe on it" (forgive my analogy).

Good luck!

Dutchy

Dear Friend,

Actually your problem seems difficult, but it is simple to absorb the vibration using rubber washer at any fixation point in addition to fixe a (free weight with spring as a vibration absorber). Thus, the question is how to know the weight and the stiffness of the spring? The answer will be by trail and error, you have to get several wights and springs and hence, you can try the most suitable combination of free weight and spring. (please remember the weights must be very small compared to the weight of the pump also the stiffness must be very small).

Best Regards,

Hi mostafa,

Did you try the pump out before you connected it to whatever it is set up to do? And did the pump vibrate then? If it is a new pump and vibrated (when it was designed presumably not to) then you should try and get a replacement.

If it is an old pump, it could be whatever it is pumping that is making it vibrate. But any vibration, as first pointed out by 'ozzb' in post #2, is detrimental to the pump and or the system it is connected to. It could be a bent shaft or part of the pumping mechanism may have broken. Whatever it is as you have hinted you must sort it out.

Can you see the back-end of the rotor and is it moving in a concentric circle? Then you have to at least assume the shaft or impeller are at fault. Without any work to do the pump should start and spin freely and completely without vibration.

I have to say the fitting of the pump is a bit 'hit or miss' and this should be done properly with a level base, (if it is on concrete) and or rubber mounts, perhaps similar to Engine mounting blocks in a car?

Good luck, and go and do the job correctly.