Previous in Forum: Pressure Control Valve Parallel Operation   Next in Forum: Yokogawa CS3000 MLD block
Close
Close
Close
6 comments
Anonymous Poster

Seismic Vibration Probe

12/24/2009 4:28 AM

hi one of our pump is frequently tripping on seismic HI vibration . B/N 3500 system slot 2 ch3 goes danger alarm hi other related probe gives only vibration alarms which on motor side .we check by overriding the trip and found that vibration are shown by the probes does exist but our vibration monitoring team says that the vibration are normal . what is the correct way to know the solution of the problem ?

Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.
Commentator

Join Date: Mar 2009
Posts: 61
Good Answers: 3
#1

Re: Seismic Vibration Probe

12/24/2009 1:25 PM

1. Consult with your vibration monitoring team and get a survey/assessment done by an independent third party. Check not only the machine parameters but also check process operating parameters/conditions and piping arrangements for anything that may be outside of what was specified for the machine operation.

2. Check the integrity of your installation, find out what type of test equipment is available and what type of simulation can be done with the probe connected to the system with the actual installation i.e. only the probe should be removed from the machine all connections and existing cabling should remain intact. Grounding can have serious adverse effects on machine measurement/monitoring equipment. If all seems to be good then see step 3.

3. Consult with the equipment manufacturer and provide them with your findings, if they agree that the vibration levels are normal or acceptable then it may mean that the trip setpoints etc need to be reviewed and adjusted again in consultation with the equipment manufacturer. Or it may mean that you've got bigger problems (some of which are easily rectified) such as severe pipe strain, misalignment, excessive thermal growth, mechanical imperfections with the machine train itself, civil or structural imperfections with the pump base or plinth etc or other design problems.

No matter what all of the problems can be rectified, it may cost you an arm and a leg but they can be fixed and will save you money and alot of headaches in the long run.

Reply
Participant

Join Date: Dec 2009
Location: Site, Fertilizer complex.
Posts: 3
#2

Re: Seismic Vibration Probe

12/24/2009 4:05 PM

Here are some checks that can be useful,

1. Check your termination of that very probe from the Proximiter and/or extension cable.It might happen that due to some connection fault.

2. If the pump is run for the very first time after a big gap, then it is a big chance that at start , the shaft might experience a GLITCH, that would not be dynamic vibrations, then rather check for electrical/mechanical run-out.

3. If all is well, then call an inspection team with ADRE and see to it that if the vibrations are tolerable you might need to adjust the trip setting, by discussing it with equipment/maint. team and vendor.

Reply
Guru

Join Date: Aug 2007
Posts: 1790
Good Answers: 87
#3

Re: Seismic Vibration Probe

12/26/2009 8:00 PM

So is this an accelerometer? Or a proximity probe?

If it is seismic that leads me to believe that it is an accel.. Your vibration team needs to make sure they are comparing apples with apples. I suggest that they hook their analyzer to the bnc jack on the front, and then use a FMax as far out as possible. The BN monitor uses a peak detector, so very high frequency vibration does not get filtered out like it does on a data collector or other analyzers.

I suspect that the mounted resonance of the accel is being excited, this would be a vibration frequency at 30 Khz or so.

Also you mention it is a pump, if it is a Sundyne pump with an integral gear box, then gear mesh frequency vibration would be very high, and picked up by the 3500 system and might not be picked up by the vibration data collector. Check the frequency span on the accel that is mounted, and compare it with the one the vibration team is using. The BNC accels often go out to 20 Khz, where the standard accels with a data collector are usually only good to 5 Khz.

Reply
Anonymous Poster
#4
In reply to #3

Re: Seismic Vibration Probe

12/28/2009 11:32 AM

sound's good thanks I will check and come back to u

Reply
Commentator

Join Date: Aug 2011
Posts: 76
#5
In reply to #4

Re: Seismic Vibration Probe

08/22/2011 4:52 AM

CR4 ADMIN: Deleted Post

Spam: This post was deleted because it contained advertising outside the Commercial Space forum. Please review Section 14 of the CR4 Site FAQ about advertising.

Reply Off Topic (Score 5)
Guru
United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain. Kettle's on.
Posts: 32048
Good Answers: 838
#6

Re: Seismic Vibration Probe

09/25/2024 6:02 AM

One of the reasons for <...HI vibration...> is running one of a number of pumps extensively without running the others; when one of the others runs it can be found that "Brinelling" has taken place in the bearings and that has caused small flats to appear in the shaft and it is the bearing running over these flats that causes vibration.

It's not easily fixed, though it is preventable:

  • Don't mount more than one pump on each subframe.
  • Toggle the duty on the pumps more frequently, so that there is less risk of flats appearing on the shaft.
__________________
"Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
Reply
Reply to Forum Thread 6 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.
Copy to Clipboard

Users who posted comments:

Anonymous Poster (1); dabdool (1); electricaleng (1); Muhammad Ismail Shakir (1); PWSlack (1); Steve S. (1)

Previous in Forum: Pressure Control Valve Parallel Operation   Next in Forum: Yokogawa CS3000 MLD block

Advertisement