The fan belt was changed from condition monitoring to fixed time replacement at 24 months. 24 months was decided on by looking at the pareto for fan belt life, talking with vendors and local mechanics / fitters.
Same for pulley change out every four years.
test vibration switch gets extended by using the calculation of acceptable risk. PRmf = (1 over MTBFtive)x (1 over MTBFted)x (half the Failure Finding Interval)

The data Vee is going to refer to is provided here
Some of the data was sourced from CMMS records dating before the two year period. This data comes from two sites. It has been combined to present a training case study but I can say to readers the data is what we have found.

This message has been edited. Last edited by: Steve Turner,

2yrsfnfandowtime.xlsx (14 KB, 11 downloads)

Steve,
Thanks.
The next item to clarify relates to the physical location details. For this, reasonable estimates are enough.
1. What is the elevation of the pulleys wrt the floor?
2. What is the elevation of the lower frame wrt the floor?
3. What is the distance between the pulley centers?

Also, are the pulleys of similar size or is one larger than the other? If the latter, which is larger and (approx) by how much?

Steve,
In order to work on the belt/pulleys, I note there is an access door in the lower mesh.
Does this mean that
1. The fitter reaches in with his upper body only through the door to reach and work on the components, OR
2. Does he enter the protected chamber fully, support himself on the protective mesh (on planks?) to carry out his work? How much headroom is available inside this chamber (lower frame to upper frame)?

Vee,
The document I presented is a schematic. No more than that.
When we did the analysis we did not go out and take measurements.
I never have gone to this level of detail in an RCM / PMO2000 analysis. We start the program with someone from the group drawing a schematic like the one I have posted and if design issues arise, we document them.
If there is a complex design problem with the asset or system being studied, we refer it to an RCA group. If there is an obvious design change, it will be dealt with in the group.
It then becomes an RCA workshop rather than a PMO2000 workshop.
One of the outcomes of this case study is redesign. If this is the conclusion you are driving to, then I agree.
If you are driving at something else, can you please let me know what your hypothesis is, so I can agree or disagree - then if I disagree, provide you with the data you need to support your argument.
Regards
Steve

This message has been edited. Last edited by: Steve Turner,

Steve,
We all have our ways of working on any problem. I do not work on any Reliability problem, be it RCA, RCM or a general reliability engineering study till I understand it as well as possible. Normally I visit the site and talk to the people etc. as explained earlier. You work differently, perhaps that suits you better. You may recall that I did not take part in Terry's virtual RCM exercise. My decision then was precisely for this reason.
At present I am not ruling in or out any design issues; I do not have a view on that as yet. Once I have a comprehensive picture, I will state my premises and seek your confirmation that they will fit the case. Only after that can I offer my views on the case. I ask for your patience for some more time.
In my last request, I was only seeking ball-park estimates, to get a feel for the practical issues those who do the physical work face. I am not seeking measurements, but if you have seen the site(s), you must have a fair idea of these. All I am asking is for you to share them. Humour me.

Vee,
I am sorry but I dont recall sufficient detail to answer your questions.
And, I dont go taking these dimensions and ask those types of questions.
Where do we go from here?

Steve,
It means I have to make assumptions, which I try to avoid. I will ask you to accept them or offer your own estimates, which is what I was asking now.
Let us move on to another question.
In a new or as-good-as-new condition, when all the components are properly installed and operated, alignments and balance in order, what is the fan speed? Your minimum acceptable is 160 rpm, but is that the same on a new or AGAN state? Again ball-park estimates will do if tachometer readings were not recorded.

Vee,
the fan speed is above 160 rpm. The group does not know what it is. It is probably set by the configuration of all the motors, gearbox ratios and pulley ratios. It may well be 180 for all I know - and for all the group knows. All they know is if the alarm is not sounding, the process is being supplied with enough air.
The alarm is set to sound if the rpm goes below 160 rpm which the users define as an alarm telling operations that the fan belt is off. It could also mean something else has failed.

Hi ....

anyone managed to open the XL fine.....

it is saying the zip file is corrupted

cheers

It's better to ask the owner or rep of these fans of those estimates to avoid making assumptions. If the fans belong to Ollie, perhaps he could provide the dimensions here.

Steve,
On to a project management question next. My practice is to divide the project into five phases, as follows:
1. Gathering of data - talking to people, documents, drawings, cost and CMMS data etc.
2. Data sorting and statistical analysis e.g. Pareto, Histograms etc.
3. Actual Maintenance Strategy analysis - in this case RCM or PMO 2000 analysis.
4. Presentations and Reports.
5. Implementation.

Considering only 1-3 above as 100% (i.e leaving out the last two), what is the percentage distribution of resources used in each of the 3 phases in your Case Study, treating it as a real project? And what does 100% mean in manhours?

Steve
Please advice whether the following premises I am making are correct from your perspective. If they are not, please correct them to suit your understanding.

1. Purpose: To cool X Tons/hr of product at P barg. from Y˚C to Z˚C 24x7
2. Local contract infrastructure can provide modern technology, instruments and technical services etc. at relatively short notice
3. Spares such as Gear Box, Pulleys, Belts and consumables are in site stores; service levels are satisfactory
4. Ops. & Eng. Staff are competent and generally work to good QA stds.
5. Trip or planned stop of a Fin Fan cooler does not impact on Plant safety or environment
6. Client recognizes that small Plant Changes may be required for optimal performance and has budgetary provisions

This message has been edited. Last edited by: Vee,

Rennie,
Here is the file again.
please email me at steve@omcsinternational.com if you still have trouble.

ForumData.xls (200 KB, 6 downloads) fan downtime data

Answers to Vee's questions
On to a project management question next. My practice is to divide the project into five phases, as follows:
1. Gathering of data - talking to people, documents, drawings, cost and CMMS data etc.
One or two days depending on how difficult it is to get info
2. Data sorting and statistical analysis e.g. Pareto, Histograms etc.
Included in above
3. Actual Maintenance Strategy analysis - in this case RCM or PMO 2000 analysis.
A good group will complete this fin fan in one day.
4. Presentations and Reports.
Half a day
5. Implementation.
Depends on the changes. Merge into SAP for example would take minutes. Getting training done or changing roles can take more time.

Considering only 1-3 above as 100% (i.e leaving out the last two), what is the percentage distribution of resources used in each of the 3 phases in your Case Study, treating it as a real project? And what does 100% mean in manhours?
Preparation is done by the facilitator talking to people.
The workshop can be done with three people - Operator, mechanic and electrician.

Purpose: To cool X Tons/hr of product at P barg. from Y˚C to Z˚C 24x7
This fan drives a heat exchanger - We dont know precisely the airflow or the BTU.
2. Local contract infrastructure can provide modern technology, instruments and technical services etc. at relatively short notice
they are at hand and available. This is not a remote asset
3. Spares such as Gear Box, Pulleys, Belts and consumables are in site stores; service levels are satisfactory
All spares are on site.
4. Ops. & Eng. Staff are competent and generally work to good QA stds.
Generally but not perfect. Will skip proper procedures if under pressure
5. Trip or planned stop of a Fin Fan cooler does not impact on Plant safety or environment
Loss of the fan does not compramise safety or environment.
6. Client recognizes that small Plant Changes may be required for optimal performance and has budgetary provisions
Modifications are put on the list and take thier time. Mods must return at least 10 to 1 in the first year to be considered.

Steve,
Thanks for confirming all but the following premise.

quote:

Purpose: To cool X Tons/hr of product at P barg. from Y˚C to Z˚C 24x7
This fan drives a heat exchanger - We dont know precisely the airflow or the BTU.

I did not mention air flow or BTUs, so let us not add needless complications.

The raison d'tre for the existence of the fan is to blow air past the fin fan cooler. It is the cooler that handles the product, not the fan (directly). Of course, without the fan , the cooler would not work, just as the fan would not work without the motor.

So, at the top of the food chain, it is the cooler that has to be managed, because that is what produces the result with the help of the motor, coupling, gearbox etc.
To specify what we need from a cooler, we do not need to talk about BTUs. All we need is volume or mass flow rate of product cooled, inlet and outlet temperatures.

If it was a water cooled exchanger, we would not talk about the water circuit alone, we would consider the product circuit as well. The fin fan is only different in that the coolant is air.

Steve,
Please advise about general weather conditions. One or more of the following may apply
1. Hot and humid most of the year
2. Rains frequently, several times a month, or rains rarely
3. Dry and dusty most of the year
4. Wide (or narrow) range of temperatures day/night and summer/winter
5. Experiences stormy or hurricane seasons

Vee,
The site is on Jurong Island in Singapore.
Close to the sea. Hot and humid.

quote:

Please advise about general weather conditions. One or more of the following may apply
1. Hot and humid most of the year
2. Rains frequently, several times a month, or rains rarely
3. Dry and dusty most of the year
4. Wide (or narrow) range of temperatures day/night and summer/winter
5. Experiences stormy or hurricane season

Vee.
I am not sure what you are getting at here.
The argument seems like the song about the "old woman that swallowed the fly".
The motor drives the fan which blows air which cools the heat echanger which cools the water which cools the raw material which feeds into the next process which goes into the next process which reacts with this and that to produce something that gets shipped to the warehouse which gets stored and then packaged.
In any analysis, one surely needs to set system boudaries. Ours is the fan which produces airflow. Its role is to provide air that absorbs heat so I would think its cooling capacity or BTU is the real performance standard.

quote:

I did not mention air flow or BTUs, so let us not add needless complications.

The raison d'tre for the existence of the fan is to blow air past the fin fan cooler. It is the cooler that handles the product, not the fan (directly). Of course, without the fan , the cooler would not work, just as the fan would not work without the motor.

So, at the top of the food chain, it is the cooler that has to be managed, because that is what produces the result with the help of the motor, coupling, gearbox etc.
To specify what we need from a cooler, we do not need to talk about BTUs. All we need is volume or mass flow rate of product cooled, inlet and outlet temperatures.

If it was a water cooled exchanger, we would not talk about the water circuit alone, we would consider the product circuit as well. The fin fan is only different in that the coolant is air.