valve world 2004 - fieldbus · diagnostics and more importantly ‘prognostics’ gives us the...

Fieldbus Overview India

© 2007 Fieldbus Foundation

Fieldbus FoundationFieldbus Foundation – India Marketing Committee

Technology Event

ISA EXPO – 2007,

Pragati Maidan, New-Delhi

Fieldbus Overview India

© 2007 Fieldbus FoundationMFX: May 2007

3© 2007 Fieldbus Foundation

What is ‘Performance’ ?“the act of performing; of doing something successfully; using

knowledge as distinguished from merely possessing it”

Therefore ‘Overall Performance’ in relation to a plant with Valves, maybe could be defined as:-

‘‘the act of using our knowledge (and experience) to operate and the act of using our knowledge (and experience) to operate and maintain the valves in a way that improves the success of the maintain the valves in a way that improves the success of the plantplant’’


Overall Valve Performance‘‘the act of using our knowledge (and experience) to operate and mthe act of using our knowledge (and experience) to operate and maintain the aintain the valves in a way that improves the success of the plantvalves in a way that improves the success of the plant’’..

This is a reasonable and fair definition – as our main interests are to:-Run the plant profitably – and therefore also keep our costs as low as

possible.

Make a good product of predictable, consistent Quality and Quantity.

Ensure Health and Safety – avoiding accidents or failures thatcause accidents.

Reduce the risk of unplanned shut-downs and extra work.


Following this logic, in order to successfully…Run the plant profitably – and therefore keep our costs as low as possible.ANDMake a good product of predictable and consistent quality and quantity.ANDEnsure health and safety – avoiding accidents or failures that cause accidents.ANDReduce the risk of unplanned shut-downs and extra work….

Then knowledge, experience and investigation is needed.Then knowledge, experience and investigation is needed.

But where does this come from ? What shape does this take ?It feels like a huge task………


But the solutions are available and are around us - Some are obvious and familiar and some are not so….

Choosing the right Valves for the application.This is obvious and familiar and yet how often do we see the wrong Valves selected for an application !

Following the recommended maintenance procedures and schedules.Again an obvious statement, but some plants are more dedicated to maintenance and safety than others.If you have any doubts here and think this is unlikely, just think of the news such as the problems and resultant court action at BP. …..


From Times OnlineAugust 15, 2006BP sued over Prudhoe BayBy Michael Herman and Agencies

Senior managers at BP are facing legal action in the US accusing them of breaching their duty to shareholders by allowing equipment at the Prudhoe Bay oil field in Alaska to deteriorate. A lawsuit filed in New York yesterday on behalf of a private investor claims that senior executives at the company, including the chief executive, Lord Browne of Madingley, failed to carry out essential repairs before the oil field, America’s largest, had to be partially shut-down. The closure caused significant disruption to US oil supplies and caused BP shares to fall."Despite their awareness of the dangerous effect of the corrosion in the pipeline, defendants repeatedly failed to fund the work necessary to correct the problem," the suit alleged. It did not specify an amount sought in damages.A spokesman for BP declined to comment, but the company has previously said it is expecting a repair bill of around $200 million (£106 million) to fix the field.

http://business.timesonline.co.uk/tol/business/law/corporate/article609577.ece


For the Athlete or Footballer, we need to ensure:-That there is a natural potential for the sport. There are no illnesses or physical damage.The correct training is followed.We use the best and most appropriate shoes, clothing, bats, balls

or other necessary equipment.There is a good, healthy diet.Get a good amount of rest and sleep.A positive mental attitude.Emotional well-being.The development of Confidence.An excellent game-plan.

So if we want to ensure safe and successful operation, we could think about the following analogy.

Running Valves on a plant can be likened to the careful training of an Olympic Athlete or a World-Class footballer.


Ignore illnesses and physical damage.Not bother to train.Use cheap and substandard shoes, clothing, bats, balls or

other necessary equipment.Eat ‘junk’ food.Think only about failing and just ‘getting by’.Feeling sad and low.Not bother to effectively plan.

What you definitely would NOT do is:-

And of course this kind of approach is not good for improving And of course this kind of approach is not good for improving Overall Valve and plant performance either !Overall Valve and plant performance either !


The analogy is close to the situation of a Valve on a plant because:-For the Athlete or Footballer, we need to ensure:- For Overall Valve Performance, we need to ensure:-

That there is a natural potential for the sport. >>

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We select the right Valve and Positioner for the job.

There are no illnesses or physical damage. The Valve and Positioner are in good condition.

The correct training is followed. We operate them in the correct way.

We use the best and most appropriate shoes, clothing, bats, balls or other necessary equipment.

We utilise the right tools and prognostic systems.

There is a good, healthy diet. We ensure a clean air supply and an appropriate service.

Get a good amount of rest and sleep. The valve has a regular maintenance schedule.

A positive mental attitude. Being pro-active in using the most advanced tools.

Emotional well-being. Trust in our own abilities and training.

The development of Confidence. There is confidence in the abilities of the suppliers.

An excellent game-plan. The plant is well-designed, controlled and operated.


Consider this…..

Are you really concerned about the health and performance of your valves ?


Surveys tell us thatSurveys tell us that…… Sadly, Users are not concerned enoughSadly, Users are not concerned enough

The majority of Users are only concerned with Critical valvesTypically <20% of installed base

Many control loops are left in manual.In case the valve is not in good shape.

There isn’t a Pro-active approach.The current philosophy is: “If it isn’t broken, don’t fix it”

There is a slow take-up of new technologies and advanced prognostic tools.


As previously stated, the Top reasons to be concerned with Control valves are:-

The mechanical nature = Which means a Higher failure rate.They are exposed to harsh processes and environments.To maintain and improve plant safety.To reduce operational and maintenance costs.

e.g. air consumption, repairs, shut-down costs, eliminate failure risk etc.

The potential for increased process efficiency / product yield.The possibility for increasing process ‘Up-time’.

Control valves are one of the Most Expensive items of plant equipment to maintain.


The solutions are available and are around us - Some are obvious and familiar and some are not so….

Having good information from our technology – in order to ‘See’ what is happening in our process.

Using alarms and warning systems that give us a prediction of a problem/failure/plant upset.

Reduce the risk of unplanned shut-downs and extra work

Diagnostics and more importantly ‘Prognostics’ gives us the essential tools for this –but who uses them ? Who understands them ?Too often they are seen as expensive, time-consuming extras rather than highly useful and beneficial tools.

Definition: PrognosisPrognosis (literally fore-knowing, foreseeing) is a medical term denoting the doctor's prediction of how a patient's disease will progress, and whether there is chance of recovery – seeing ahead to predict the outcome before it happens.


So what may go wrong with a control valve and reduce overall performance ?Actuation

Broken SpringAir leakage (diaphragm, tubing)Bench Range Calibration

Abnormal FrictionPackingGuides / Trim

PositionerLinkagePneumatics (I/P, Relay)Calibration / PerformanceLoss of air supply

Trim Wear (plug/seat)Seat leakageBody damage

Packing WearFugitive EmissionsStem Wear/CorrosionSafety Hazards

Application ProblemsCavitation / FlashingNoiseVibration


Some of the key points we have identified so far in improving overall performance are:-

The importance of selecting the right Valve and Positioner for the job.- This seems easy, but are all Positioners created equal ?

Making sure the Valve and Positioner are in good condition.- But how do we effectively and yet easily monitor this on a day-to-day basis without lots of extra work ?

We operate and monitor them in the correct way.- Wouldn’t it be good if we had automated and simple to understand notification or warning if something was wrong ?

We utilise the right tools and prognostic systems. - To get the best advantages from our technology.

The valve has a regular maintenance schedule.- But without unnecessary work, cost, effort or delays to production.


What do we need ?To have good Valve performance, as a well as a good Valve we need a good Positioner.

But what are the characteristics of a good Positioner ?

It must be Reliable.It has to be Accurate.Its performance must be Consistent/Repeatable.Easy to set-up and use.Provides additional Intelligent features – such as diagnostics. Easily integrates with your DCS/Control strategy.Be ‘Fit & Forget’.


It is the needs of the User and the Plant that determine the final characteristics of a good Fieldbus Positioner.


More extensive features, such as diagnostics represent the key area that helps with overall performance improvements – by identifying an impending problem before it becomes serious and has an impact on the plant.


One aspect of improving performance – by reducing Plant Down-time - is the ability to quickly fix any fault that might occur. A Fieldbus Positioner designed with a small number of modular parts greatly assists in this task.


The key advantages of adding a Fieldbus Positioner:-

• It creates an information portal to monitor valve health.

• You can see exactly what is going on.

• Remotely Access the Control Valve.

• Improve Control Valve Performance.

• Monitor The Health Of Valves Online.

• Assess Mechanical Health Using Diagnostics.

• You can see if you are using the valve in the optimum way and if it is correct for the application.


Controller Range = 0 - 30K#/HrSetpoint=16.3623 K#/hrPV= 16.4517 K#/hr

Inlet Pressure = 3600 PSI Outlet Pressure = 3400 PSI

Dynamic Matrix ControlMain Syngas Feed, Tag: X0F102Valve: 2” 41000 Series (ATO)Cv = 20 , Stroke = 0.8”3 - 15 # Spring Actuator (ATC)50 # Air Supply

Dynamic Stem Load RangeControl = 160 psiSeated = 3568 psi

Dynamic Stem Control AccuracyControl = 0.4768 psiSeated = 10.623 psi

Dynamic Control Ratio = 335.8:1

Stem Position Resolution = +/- 0.002384”(1/2 thickness of a human hair)

Installed Total Loop Precision = +/- 0.298%

Using Reliable and Highly Accurate Fieldbus technology enables you to increase the Total loop accuracy


After installing a high quality Fieldbus Positioner – it is possible to achieve something in the order of a 53% reduction in the standard deviation from the set-point.


Installed Valve Performance

+ / - 55 Thousandths of a Percent

Looking more closely…….


The Performance gains are also significantly enhanced within a Fieldbus Positioner through the complicated software algorithms.

These are used to simplify otherwise difficult tasks that would be tedious, time-consuming and frustrating to set-up manually.

Fortunately, this is all handled automatically through the software and set-up wizards – making life easier, quicker and less complicated.

For example:-Auto-tuning the Positioner to match the Valve characteristics.Setting the aggressiveness of the Positioner response

– This adjusts the speed of response.

If you had to do it manually, it would be like tuning a musical instrumentinstead of an electronic one.


The Auto-tune Wizard allows easy set-up.Progress Screen

TimersResults Graph

Export to ExcelPID Comparison TableProgress Screen

Timers


When we start to consider the Diagnostic abilities of Fieldbus equipment, we step into a bright, new world.

It gives us the ability to be ‘Electronic Doctors’ – assessing the health and well-being of our equipment.

The key is to do it in an easy to use and a comprehensible way.

Of course the full benefit comes from integration into a DCS.


5 Pressure SensorsAir SupplyI/P OutP1 Relay OutP2 Relay OutAtmospheric Pressure

P Air Filter / Regulator

Servo (I/P)

Pneumatic Relay

Actuator

Valve

P1

P2

P3 P4

P5

CPU

C1

H1

T1

P4P3

P2C2

4-20 mASetpoint I/P Servo

The Heart of Diagnostics is in the Positioner, not the DCS.


1 Temperature Sensor

2 Loop Current Sensor

1 Hall Travel Sensor

T

C

Air Filter / Regulator

Servo (I/P)

Pneumatic Relay

Actuator

P1

P2

P3 P4

P5

CPU

C1

H1

T1

P4P3

P2C2

H

4-20 mASetpoint I/P Servo

Having a high number of sensors allows the detection of more Valve issues.

Valve


Types of diagnostics, which assist in maintaining and enhancing performance are:-

Continuous Diagnostic DataTime OpenTime CloseTime ‘Near’ ClosedCycle Count Travel Odometer


More complicated and useful diagnostics are:-

Off-Line Signature DiagnosticsHigh Resolution Step TestHigh Resolution Extended TestPositioner Signature

On-Line Valve Diagnostics28 Alerts

– Including, Low Air Supply, Actuation Problem, Deviation, etc.

Careful and thoughtful use of this data provides us with an invaluable insight into the workings and condition of our Valves.


On a more fundamental level, we can instantly see where the fault lies.Whether it is in regard to its Operation, its firmware or the electronics.Alarm Historian

Current and Historical for Every Alarm.Stays in Memory Even after Loss of Power.


Accessing Diagnostic Data via a DCS – allows the sharing of data.

FF I/O

Valve alarmsActual positionIntegrated logic

TrendsValve timers

OperatorConsole

Asset ManagerCalibration,

Configuration,Literature

Etc.AssetManager

TB

Device alarmsHistorian timersValve odometerDeviation alarmCondition monitoring

FFPlug-In

DeviceViewer

Monitor StationControl Station

Valve SignatureUser FriendlyConfig. +Cal.TroubleshootCommissioning

Quick OverviewOf device/valveCondition.

database

FFStandAlone

High Speed Network

H1 Segment


DeskPro

Data ArchivingPredictive Maintenance

OPC

Client

CONTINUOUSCycle Counter

Travel AccumulatorTime Closed

Time Near ClosedTime Open

OFFLINEPositioner Sign.Actuator Sign.

Step Sign.Overall FrictionSpring Range

Seat Load

ONLINEProcess TrendActual Travel

Output PressureInternal Set-pointDevice’s Health

FF COMMUNICATION

FF OPC

Fieldbus Valve Positioner

I/O SUBSYSTEM

L I F E B O O K Portable MaintenanceStation

Operator’sConsole

HandheldCalibrator

Maintenance Station

Valve D

iagnostics

Ethernet

Digital Positioner


Being able to fully engage and interrogate your Fieldbus equipment from the control room is another great advantage.

It encourages the User to carefully examine the health, configuration and performance status of the Positioner/Valve while it is in action – backed-up by automated monitoring and self-checking features.

Without this ability, the only way to get data on Valve behaviour would be by going onto site and watching it for a few days.


The data gives us access to the Process, Physical, Maintenance, Safety and Reliability information.


The clever part is to convert the sophisticated performance and diagnostic data into a simple to interpret way.

In this case, a traffic light system is used – Red standing for a major problem, Orange for a predicted problem and Green for all OK.


Creating Information From Data

Built-In historian in the Fieldbus Positioner 80

2015

92

8

80

65

35

1510

90

5

0102030405060708090

100

Valve A Valve B Valve C Valve D

hrs openhrs closedhrs n.closed

High % time nearly closed= Trim Erosion, Oversized Valve

Valve not being Exercised = Possible Stiction

Implementing Alarms in to the DCS

Historical Trace


Case study

Industry Request

The Objectives The Tools

The Results

• Read Field Device Data Into DCS• Centralize Field Device Data• Manage Assets Effectively• Optimize Process Control

• Predict Valve Failure• Monitor Health of Valve• Analyze Applied Valves• Remotely Troubleshoot Valves

• A high quality, digital Positioner • Foundation Fieldbus protocol• Digital I/O’s or Multiplexors• AMS, PRM and Plug-In Concept

• Increase Process Yield• Reduce Maintenance Cycle• Online Overview Of Valve’s Health• Better Utilization of Man / Hours• Integrated Diagnostic In DCS


Prognostics in action – Case study: BASF, Geismar, Lousiana

1) Total service Time =Time open + Time closed(59 + 6 hours = 65 Hours)

2) Cycles / Hour = Cycles / Service Time(5001/63 = 76.93 Cycles/Hour)

3) Life Estimate = [Life Estimate/Cycles / Hour] Minus[Current Accumulated Time]

[8,000,000/76.93] - [65] = 103925 Hours= 4330 Days= 11.86 Years

Terminal Life Estimation - Bellows Seal

1000

10000

100000

1000000

Valve Movement as a% of Free Travel

Valve Cycles( 000's )

Expected Cycle Life (000's)Masoneilan Design Criteria

Expected Cycle Life (000's) 1000 3500 10000 1000000

Masoneilan Design Criteria 3500

5.0% 4.0% 2.5% 0.30%


Translation to Operational Expenditure savings:-

Industry Request

The Tools

The Results40% of industry costs relate to maintenance in some way

Request :-• Reduce maintenance costs on Power Plant• 40 Valves• Cost $110,000 every two years

Fieldbus technology was used to:-• Predict valve failure• Monitor health of the valves• Analyze valve behaviour• Remotely troubleshoot valves

Maintenance costs were reduced, as only 6 valves actually needed work:

Thus, costs cut from $110, 000

To $30,000 Made up of:-

Testing, field repair: $14,000Removal, Reintstallation and shop repair: $16,000

Power Plant: USA

valve world 2004 - fieldbus · diagnostics and more importantly ‘prognostics’ gives us the...

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