Tagged With "failures"

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Who owns Equipment Reliability?

TPickett ·
Who owns Equipment Reliability?
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Intro to the Maintenance P-F Curve

TPickett ·
Intro to the Maintenance P-F Curve
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MTBF and Useful Life

TPickett ·
MTBF and Useful Life
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BALL BEARING FAILURE ON 1,3 MW / 6KV SCHORCH MOTOR IN REFINERY

George NV ·
Preventive - predictive maintenance team has called for withdraw and repair large electric motor , vertical , 1,3 MW , 6 KV , 745 rpm driving large multistage pump . Finding was DE bearing wear  ( inner ring ) . That was confirmed upon disassembly and inspection .  Strange finding is the wear pattern found on the outer race of the angular contact ball bearing , 7330 B , mounted inboard on top side . This bearing only for axial loading . Next to it , outboard is a 6330 C3 brg . This...
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CMMS as viewed by Reliability Engineers

planschd2 ·
I wish reliability professionals would recognize that we too are important . There are many experts in the field of condition monitoring, defect elimination, root cause analysis, RCM analysis, etc. and they believe strongly in their approach. The CMMS is a valuable database containing asset registers, asset failure history, asset criticality, spare part data, warranty information, asset age/installation-date/replacement cost, asset classification data, job plan libraries, PM/PdM...
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How important are asset taxonomy and coding?

Reliability ·
How can you zero in on maintenance improvements without failure data?  
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Low pressure Steam Turbine blades Failure

aftab jadoon ·
Hello everybody, we have been experiencing blades damage at 6th stage of low pressure turbine. its 325 MWe power plant with tandem compound arrangement of 1 HP and 2LP with intermediate MSR. each LP consist of 7 Stages. there are tottal 480 blades in...
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Moving cable failure detection

Reliability ·
Posted on behalf of an associate I was at the IMC convention in Florida this past week. All was good, but the one thing that no one seem to touch on, which is the cause of most of our down time, is early detection of wiring breakdown. We have a lot of moving cables, whether its on a robot, in an energy chain, on a drop lift, etc. Most are low voltage, AC and DC. Is there anything out there that addresses these problems? We do the usual inspections, but we get a lot of wiring that breaks down...
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Predictive Analytics

ashishsoni ·
Guys, I have been given the responsibility to research 3-5 solutions available in market for predictive analytics to prevent unplanned maintenance, understand in-depth root causes of failure at multiple levels pinning to the lowest asset element, achieve optimal production efficiency, ensure supply chain is leveraged to the best limits and achieving all of the above in a cumulative fashion? Any suggestions?  
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Root Cause Failure Analysis

Rana Yasir Ayub ·
One of our customer (cement plant) facing unplanned shutdown just 1 hr ago ID fan(Raw Mill) Dive End Bearing is damaged which was newly installed 10 days ago in plan shutdown. We need help in Root Cause Failure Analysis,,, All other Bearings of Fan as...
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Should failure modes match failure codes?

Reliability ·
Should the failure modes you identify in a Reliability-centered Maintenance analysis or a Failure Modes and Effects Analysis be the same or match in some way with the Failure Codes used in your CMMS/EAM work management system?
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Run to Failure

Reliability ·
Run to failure is a maintenance strategy True or False ?
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Run to failure is a maintenance strategy?

Reliability ·
Run to failure is a maintenance strategy? True/False
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Thermography on mechanical breakers

chrisjdwhite ·
Hello Everyone,   Just over a month ago I posted on the Root Cause Analysis Forum about a failure on a mechanical breaker (spring), It appears to be a fatigue related failure and the breaker timing was reduced. I figured I would ask on this post...
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Sufficiency of Historical Time to Failure Data

lewiseyo ·
I am an M.Eng student and doing a work on determining the Reliability of a centrifugal pump. I have been able to get the Time to failure historical data of the centrifugal for 8yrs, but I want to know if this data is okay to determine its reliability using weibull and also if I can use same data to determine the MTBF of this pump.
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Re: Moving cable failure detection

Bill Keeter ·
Interesting question. There is none that I know of. I wonder if it would be practical to measure resistance changes in the wires. The resistance should go up as the wire thins due to stretching. The changes would probably be in the micro to pico ohm range so it would require special equipment
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Re: Moving cable failure detection

Walt Strong ·
Google: wire and cable failure detection Appears to be a lot of relevant information. Walt
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Re: Moving cable failure detection

Steve Ciesla ·
What's a nobot?
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Re: Moving cable failure detection

Dave Reynolds ·
I agree resistance changes could be detectable, but as stated the change in values will be quite small. Depending on the type of wire, solid/stranded, resistance could also decrease. I assume there are a multitude of cables/connectors that go to the robots and no two are the same? What kind of voltage/frequency is going thru the cables? Using a mV voltage drop from end to end could also be a solution. As the conductor/s break/become weak, this too could indicate impending problems. If you...
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Re: Moving cable failure detection

Fred Feurer ·
Nobot is a set jig, transfer, etc, that might have clamps, location pins, guides, etc, that may need to move every cycle and in our case, move to different positions inside that cycle. Some of these we use motion controls and some we use robot controls without the actual robot. hence.. nobot.
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Re: Moving cable failure detection

Aditya ·
There is a technique named LIRA (Line Impedance Resonance Analysis) which is very effective on low voltage cables from Wirescan Norway ( http://www.wirescan.no/product...able-test-equipment/ ). There must be service providers in USA who could work with you. In India, it is used by the nuclear plants & petrochemical industry. As I have no clients in the automation world, I cannot comment on its suitability for your application. Regards, Aditya
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Re: Moving cable failure detection

electricpete ·
What is the nature of these cable failures? Failure due to overheating at a connection resulting in open circuit? What kind of connection? Failure due to abrasion resulting in short?
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Re: Low pressure Steam Turbine blades Failure

George Kelley ·
At what point of the turbine is the balance piston leak by chamber reintroduced into the turbine
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Re: Low pressure Steam Turbine blades Failure

aftab jadoon ·
it is condensing steam turbine, which operates on saturated steam,
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Re: Low pressure Steam Turbine blades Failure

Dimaz Gesang ·
Aftab, before this happened, whether there is the operating parameters are changed ? for example, vibration , temperature , pressure.
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Re: Low pressure Steam Turbine blades Failure

George Kelley ·
Aftab, What is the inlet steam pressure? Are the steam lines equipped with enough traps? A separator would be nice for a saturated steam turbine along with traps in the turbine belly. the last couple of stages would probably be in a vacuum and running cool. The reason I mentioned the balance piston leak off earlier is this leak off would be reintroduced to the turbine at maybe the 6th stage? this steam would still be hot in comparison to the blades at low loads due to the reduced flow rate,...
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Re: Run to failure is a maintenance strategy?

Derek Burley ·
True - if the object of maintenance / reliability is ultimately to deliver value then part of that value is not wasting money by trying to prevent the unpreventable or spending more on preventing it than the cost when the failure occurs. I don't mean there is nothing else you can do (redesign etc). Why would anyone spend $2000 per year avoiding a failure that only costs $500 each occurrence and has a MTBF of 5 years? However, run to fail is unacceptable if failure consequences result in...
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Re: Low pressure Steam Turbine blades Failure

RiskEngineer ·
Take metallurgical samples to determine the failure mechanism. Stress Corrosion Cracking is very likely. For GE machines there have been a number of TILs issued in covering L-1 bucket (blade) failures. What is the make and year of this machine? If you have not done so yet consider making an insurance claim. Most property (and machinery) policies should pay for such failures. Talk to your risk management department.
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Re: Run to failure is a maintenance strategy?

Andika ·
i think, run to failure is the frequency of failure mode... ot the Maintenance Strategy then one of the maintenance strategy to prevent this frequency is provide the strategic spare for those part or equipment.
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Re: Run to failure is a maintenance strategy?

candy ·
Why is it not?
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Re: Low pressure Steam Turbine blades Failure

aftab jadoon ·
the turbine was given by Shanghai turbine works/company in year 2000. it operated almost 15 years. during the operation no signs and symptoms shows that the blades were damaged. the plant was shutdown for the maintenance purpose and after the non destructive testing (NDT) we found that the 23 of the blades in stage 6 were damage in both of LPs the inlet steam pressure at Low pressure (LP) turbine is 0.721 MPa with temperature of 253.4 degree Celsius . four (04) steam extractions are taken...
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Re: Run to failure is a maintenance strategy?

Dokken ·
A valid strategy dictated by the criticality and economical parameters. Criticality is the main driver and the second factor is the cost of PM Vs cost of failure.
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Re: Run to failure is a maintenance strategy?

Andika ·
After a hour of discussion with some partner, and take some example problem. I agree with your explaination, that run to fail is one of the maintenance strategy. Because run to fail is one of the way we treat the failure with eleminate and can accept the failure effect also with economic consideration.
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Re: Run to failure is a maintenance strategy?

Romaine A. Taylor ·
Yes run to failure is indeed a maintenance strategy. It is normal applied to acceptable low impact risks which are less of a financial burden to repair after failure than to maintain to mitigate or prevent failure.
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Re: Run to failure is a maintenance strategy?

Ayk538 ·
Yes its a maintenance strategy........... Its all depends on how it is implemented and under certain conditions.
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Re: Run to failure is a maintenance strategy?

CLS ·
True, provided that is is not a critical piece of equipment and that there are no safety issues!
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Re: Run to failure is a maintenance strategy?

Don K ·
Yes, but I prefer to use the term "Run to Replace". The replacement may occur after the component has failed, but it would be even better if it could have been replaced on a planned basis. Even run to failure components require parts and labor to correct. If this labor is distracted from a job of monitoring or maintaining a more critical component, then the over all risk has been increased. If the component issue could have been corrected prior to the failure, the cost of parts would be...
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Re: Run to failure is a maintenance strategy?

Jail guy ·
I agree that "Run to failure" is a strategy. Criticality must first be determined by an impartial judge, followed by an accurate cost of failure and cost of PM. If PM does not make economic sense, run to failure. True costs and criticality seem to be a challenge to many of the so called professionals with whom I work.
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Re: Run to failure is a maintenance strategy?

Oscar Rodriguez ·
Yes, but just in those cases when HSE ( Helty, sefty and envairoment) is not affected
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Re: Run to failure is a maintenance strategy?

Jail guy ·
Monitoring is also a good strategy, if it used properly and makes economic sense. However, in my past some assets have wasted much more than was saved on non critical assets by overzealous monitoring. On the other hand, monitoring on many critical assets has also been ignored with the end result of run to failure being more costly. This is why monitoring and PM needs to be analyzed on a periodic basis as well and then documented with the ability to change if one of the calculation factors ...
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Re: Run to failure is a maintenance strategy?

Bernabe ·
It is a strategy that can be effective as long as you have short periods of time between maintenance windows or able to stop the equipment at any time to correct it and someone knowledgeable is doing routine checks on it (which can cost more). It would be very ineffective and perhaps expensive if the maintenance windows are extended periods of time where if failure occurs it would cost more on production than if fixed or replaced on a timely manner.
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Re: Run to failure is a maintenance strategy?

Jail guy ·
Criticality has Health, Safety, and Environment as weighted factors. However, sometimes environmental is overrated.
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Re: Run to failure is a maintenance strategy?

Rocky R ·
Its right about here that we tend to get wrapped around the semantics axle. I would argue that, if your analysis determines the costs to replace a failed component and to repair collateral damage caused by the failure and including the cost of lost production and/or spoiled product would be less than the the cost to monitor/maintain that item you have a candidate for a Run To Failure strategy. Otherwise, some amount of monitoring is likely to save $$$ vs. just letting things fail. I think...
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Re: Run to failure is a maintenance strategy?

Chris BARCLAY ·
TRUE - If it gives the best compromise between cost, performance and risk requirements.
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Re: Run to failure is a maintenance strategy?

Bob/MVS ·
"Run to Failure" or rather 'Reactive Maintenance" in my opinion is never a good option - except for one singular option - "equipment redundancy" that requires only the flip of a switch. Albeit there are machines that are used sparingly but still contribute to production of "X" product that if, left to fail - have no effect as to timing for replacement/repair. One just can't make a statement regarding the cost of replacement Vs. the cost of a Reliability Program without taking into account...
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Re: Run to failure is a maintenance strategy?

Michael Hall ·
I don't think run to failure can be called a strategy - as that implies it is the overarching maintenance method applied across an organisation. It's a tactic - used on particular assets when circumstances and asset management goals suit it. If the total cost of failure is less than maintenance costs, it might be suitable. See any of the many Reliability Centered Maintenance decision trees. In summary, run to failure is just one of the choices available when developing a system's asset...
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Re: Run to failure is a maintenance strategy?

Dokken ·
These should be covered by the Criticality analysis, considering correct decision matrix is used to define the level of criticality. HSE must be included in your criticality evaluation.
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