Dear All
I have a problem with dynamic analysis for existing crude pump, I have some question.
1.for Anysis the pump what is important point?
2.What is the type of analysis is to be exactly for this
anlysis.and what information is need to used for analysis.
3.Now, I have to used modal in anysis(but I don't understand about mode shape and frequncy cut off selection. after analysis I saw the output report it shown many frequncy So,
I don't know which mode shape that I used to compare with the pump.

plase advice me to correct method.
(If posible plese advice me step by step)
thank you very much for every your reply

Limousine

Dear Friend,

As long as there's no any failure and piping vibration connected to pump, no need any dyn. analysis. Some times field engineers may instruct you to perform vibration or modal analysis. When there is vibration problem, field engineer provides measurement results and then you can perform modal and harmonic analysis and find mode shape which coincides vibration pattern.
If you would like to perform modal analysis from scratch with no field data,
1- Find any anticipated frequency of running pump (RPM/60) and check with natural frequencies of piping system.
2- Find system natural frequency which coincides pump frequency.
3- Plot selected mode shape to see how piping system tend to vibrate.
4- Change natural frequency of piping system by adding more pipe supports or changing the route.
5- Make sure that there is enough seperation between piping natural frequency and pump frequency. “Separation” is a qualitative measure, but 10% to 20% is often used as a quantitative measure of separation.

Dear farhad
thank you for you reply

regard
Limousine