I know "it depends", but I would like to hear what the group has to say about the following question:

What would be a conservative (meaning everyone is agreeable to it) estimate, in the form of a percentage, for how much more life is routinely realized on an asset when Vibration Analysis is used, vs an identical asset which does not benefit from a Vibration analysis program.

I would guess that sometimes it doubles the life (100%) or more, such as when lubrication problems are detected.

I would think that just routine alignment and balancing may add 5-10%.
I think 10% is a conseravative number.. what do you think?
I'll set up a poll.

Talking of influence of imbalance on bearing life use well publicized bearing life formula. Roughly, 2 times increase in loadings will cause 8 times reduction in service life.

It is not equipment life that you are saving. Most of the PdM technologies, vibration thermography, only detect problems. These problems will lead to the failure detected or not. What PdM gives you is the ability to plan and work on the equipment early. This can reduce downtime of a unit during peak demand and it can reduce the cost of the repair by fixing a small problem before it become big. You can also see savings in delaying equipment overhauls based on time and only perform them based on condition.

Oil analysis can actually stop a failure before it starts. Keep the oil in good condition can stop that first defect in a bearing.

The Electric Power Institute suggests that a savings of 10 to 1 using PdM over run to failure.

Martin- I agree totally with Ron. You can't really say that PdM or vibration will increase something more than infrared. Realistically they should be used in conjunction with each other. Recently I did some vibration readings on a set of pumps and found the motor drive end bearings were noisy. I always recommend that people use the contact probe on an airborne ultrasound unit to lube. This company didn't have one so they had me come in a help them. We lubed the bearings with the ultrasonic unit and then I took advanced vibration (10KHz Fmax waveform readings) again. The result was lowered levels of impacting and the bearing faults that were present in the high frequency (approx 100xBPFO). Now they will be able to run longer but how long is hard to tell. I have done this before too with a sealed bearing were we fed oil into it and that quieted down the bearing. That one has run for like 3 more years. The big thing that you can't figure when doing this is the load on the bearing. As David said an increase in the load on a bearing if you look at the bearing life calculation has a great effect. That doesn't mean the vibration has increase or decreased at all. Today I took vibration readings on a pump for the 1st time and the vertical readings were over 1 in/sec. Now everyone that does vibration really doesn't like to see that but this pump has been running since 2001.

Now as Ron said the calculations that you are wanting to look at is the cost per pre-failure repair over the cost per after failure repair. I have done this on the past without calculating downtime and after the repairs were done so we got a real cost for now vs. waiting to replace say the whole motor. In this case it was performing this as a consultant over a year and a half vs. the failures that we saved the company and it equated to about a 6 to 1 return. Now if you add in downtime cost on critical equipment that could sky rocket depending on your industry. The best way to take a look at cost analysis is if the efficiency is increased. Then the cost really goes up depending on the industry. Good Luck!

The other thing that I would like to add is that VA allows much more detailed anaysis of root cause.

If a bearing fault is detected, and the bearing removed in the relatively early stages of degredation, the root cause of the failure initiation is more likey to be found. This gives the opportunity to address the underlying cause of the failure.

If the bearing comes out as a smoking ruin, the evidence of the intial failure mode is probably lost, as is the opportunity to minimise the risk of having that failure mode again.

Avoiding catastrophic failure, being able to plan the work, and not dismantling equipment to see why it has been running well are all undoubted benefits, but I think a big benefit that is sometimes overlooked is the opportunity to substantially increase the equipment uptime by being able to help drive improvements in overhaul/assembly techniques.

Ian

I'm with Ian and David on this one.
Part of the condition monitoring teams role I believe is not just being nable to detect they have a problem but they also need to boast about the wins. This can be hard for some people but the more people are aware of the effort and outcomes the easier it is to justify the need for training, equipment and keeping the program running.