evaluation of electro pneumatic valve positioners...

LHC Project Note 190

1999-05-17

([email protected])([email protected])

Evaluation of Electro Pneumatic Valve Positioners for LHC Cryogenics

Wolfgang Hees - LHC-ACR Division

Ralf Trant - LHC-ACR Division

CERN, LHC-ACR-PI Evaluation of Electro Pneumatic Valve Positioners for LHC Cryogenics

TABLE OF CONTENTS

LIST OF ANNEXES ____________________________________ 3

UNITS ________________________________________________ 4

ABBREVIATIONS _____________________________________ 5

1. INTRODUCTION ____________________________________ 6

1.1. MOTIVATION_______________________________________ 61.2. WORKING GROUP ___________________________________ 7

1.2.1. Mandate _______________________________________ 71.2.2. Members_______________________________________ 71.2.3. Schedule _______________________________________ 7

1.3. MARKET OVERVIEW _________________________________ 71.4. LIST OF CRITERIA ___________________________________ 8

2. TESTS AND RESULTS ______________________________ 10

2.1. PERFORMANCE TESTS _______________________________ 102.1.1. Test program __________________________________ 102.1.2. Set-up ________________________________________ 102.1.3. Results _______________________________________ 102.1.4. Evaluation ____________________________________ 11

2.2. RADIATION TESTS __________________________________ 112.2.1. Test program __________________________________ 112.2.2. Set-up ________________________________________ 112.2.3. Results _______________________________________ 112.2.4. Evaluation ____________________________________ 12

2.3. MAGNET TESTS ____________________________________ 122.3.1. Test program __________________________________ 122.3.2. Set-up ________________________________________ 132.3.3. Results _______________________________________ 132.3.4. Evaluation ____________________________________ 13

3. OUTLOOK_________________________________________ 14

3.1. WHAT HAS STILL TO BE DONE _________________________ 143.2. MARKET DEVELOPMENT _____________________________ 14

4. CONCLUSIONS ____________________________________ 15


LIST OF ANNEXES

Annex 1 Comparison of control valve usage in LEP and LHC (1 page)Annex 2 Photos of the tested positioners (1 page)Annex 3 Description of the valve / actuator / DAQ test set-up (1 page)Annex 4 Graphical results of the performance tests (4 pages)Annex 5 Graphical results of the magnet tests (1 page)Annex 6 Comparative Evaluation Table (3 pages)


UNITS

Table 1 lists all units used in this report and a short definition.

Table 1: Units

symbol name explanation% FS percent Full Scale one of one-hundred parts of the full travel range of a valvebar bar pressure relative (to atmospheric pressure)

1 bar = 105 Pabar a bar absolute absolute pressure

1 bar = 105 Pad day timedm3 cubic decimetre volume corresponding to one litre

1 dm3 = 10-3 m3

G gauss magnetic induction, obsolete unit1 G = 10-4 T

g normal gravity acceleration due to gravity1 g = 9.80665 m s-2

Gy gray absorbed dose when the energy per unit mass imparted tomatter by ionising radiation is one joule per kilogram *1 Gy = 1 J kg-1

kg kilogram massmA milli ampere constant currentmm millimetre length

1 mm = 10-3 mn/cm2 neutrons per square

centimetrenumber of neutrons passing a cross section of one squarecentimetre

Nm3/h norm cubic metre per hour volume flow of a gas expressed in cubic metres at normalpressure and temperature (1013 hPa, 20 °C) per hour

s second timeT Tesla magnetic flux density of a magnetic flux of one weber per

square metre *1 T = 1 W m-2 = 1 kg A-1 s-2

* taken from "Scientific Unit Conversion" by François Cardarelli, Springer Verlag.


ABBREVIATIONS

Table 2 lists the abbreviations used in this report and a short definition.

Table 2: Abbreviations

CERN European Laboratory for Particle PhysicsLHC Large Hadron Collider: the new accelerator to be commissioned in 2005ACR Accelerator CRyogenics group in the LHC divisionECR Experiments CRyogenics group in the LHC divisionIAS Industrial Automation and Supervision group in the LHC divisionACR-PI Plants and Infrastructure section in the ACR group of LHC divisionEP-LHB LHC-B group of Experimental Physics divisionSL-CO COntrols group of SL divisionADC Analogue to Digital ConverterCOTS Components Off The Shelf: normal (electronic) devices that can be bought without

special radiation resistance specificationDAQ Data AcQuisition systemEMC Electro Magnetic CompatibilityEN European NormI/P A device converting a control current to a compressed air pressure

I = current, P = pressure.IP (65) degrees of protection provided by enclosures (IP code)

according to IEC 60529 (International Electrotechnical Commission standard)LCD Liquid Crystal DisplayTBC Terminal Based Conformity: a method to determine the linearity of an actuator or

positioner.


1. INTRODUCTION

1.1. MOTIVATION

Since about 1994 several manufacturers have been introducing a new generation of valvepositioners. They are called digital positioners because they have integrated micro controllers (somemanufacturers also call them "intelligent" positioners). They offer a range of features that could beof special interest for LHC:• simple installation (Fieldbus reduces cabling and therefore costs)• automatic start-up and calibration (self-adaptation to valve) means fast and therefore cheap

maintenance• communication capability (e.g. Hart, Profibus, etc.)• remote configuration• preventive maintenance planning using diagnostic data• reduced air consumption.

The use of this new generation of positioners could improve the overall reliability of the LHCcryogenic system as well as provide significant manpower savings.An analysis of the present and future cryogenic systems shows that the total number of controlvalves and their widespread distribution in the tunnel (and therefore the length of the access routes)will all be significantly different for LHC than they are for LEP. In LEP, all control valves are closeto the access points. In LHC, the control valves will be distributed evenly along the whole tunnel.LHC will make use of about an order of magnitude more control valves in the tunnel than LEP.A detailed comparison can be found in Annex 1.

Until now, there are only classical ("non digital") positioners being used at CERN. Since 1997, afew digital positioners are in use in different laboratories at CERN.Table 3 shows a comparison between the old and the new systems:

Table 3: comparison of classical and digital positioners

characteristics classical digitalbasic principle I/P converter • microprocessor controlled

• valve block or I/P convertercommunication (remoteconfiguration & diagnosis)

no yes

automatic start-up no yesautomatic diagnosis (→Alarms) only limit switches

(optional)yes

continuous position feedback signal yes (optional) yespositioner cost price digital positioner is slightly more expensive (10-20%)installation costs installing a digital positioner is cheaper (reduced inst. time)infrastructure & running costs digital positioner has highly reduced air consumption (~10%)preventive maintenance no yes (and reduced maintenance time)


1.2. WORKING GROUP

In order to evaluate these new products, a working group has been set up.

1.2.1. Mandate

• establishing the emerging types of products• defining LHC needs and wishes• selecting some products of interest• performance assessment with respect to LHC requirements and LHC operational environment

conditions.

1.2.2. MembersThe following people are participating in this working group:• J. Brahy IAS• N. Delruelle ECR• Y. Drouyer ECR• Ph. Gayet ACR/L2

• G. Lindell ACR/L2• R. Trant ACR/PI• W. Hees ACR/PI• J.-P. Lamboy ACR/MT

• L. Serio ACR/SR• P. Gomes ACR/IN• U. Jordung ACR/IN• A. Suraci ACR/IN

• R. Lindner EP-LHB is on the distribution list since July 1998.

1.2.3. ScheduleThe working group has had 7 meetings in 1998:• 1st on 22/01/98 gathering information from the different groups/sections• 2nd on 12/02/98 potential suppliers & brainstorming on needs, wishes and interfaces• 3rd on 05/03/98 definition on needs, wishes and interfaces• 4th on 02/04/98 test set-up & electrical vs. pneumatic actuators• 5th on 27/08/98 radiation tests and general tests: preliminary test results• 6th on 17/09/98 radiation tests and general tests: preliminary test results• 7th on 10/12/98 test results

1.3. MARKET OVERVIEW

The following manufacturers and products have been found during an (unofficial) market survey:

Table 4: list of positioner manufacturers

company device name system presen-tation

testunit

selec-ted

Arca (same as Siemens) 827 piezoelectric valve block ü üElsag Bailey TZID I/P converter + pneumatic 3

way valveü ü ü

Foxboro - Eckardt SRD 991 2 stage I/P converter ü ü üFlowserve (Kämmer)1 prototype electro-magnetic valves ü ü üSamson 3780 electro-magnetic valves ü ü üKeystone F793-E701 missing information ü üMasoneilan SVI I/P converter ü üNeles ND800 missing information ü üVal Controls EPP100 SR piezoelectric valve blockFisher Rosemount FloVue I/P converter üSiemens → see Arca Sipart PS2 piezoelectric valve block ü ü

1 First prototype version, based on the 1067 positioner from Bürkert.


The companies on the list in Table 4 have been invited to present their products. After this firstinformation, five positioners were selected to participate in the test program (see column 'selected'in Table 4). Photos of the selected positioners can be found in Annex 2.The companies not selected for the test programme were left out for the following reasons:

• Keystone: company and product discovered too late, slow information flow from company.• Masoneilan: company and product discovered too late, slow information flow from company.• Neles: delivery problems, low compliance with CERN requirements (price).• Val Controls: company and product discovered too late, generally low compliance with CERN

requirements.• Fisher-Rosemount: generally low compliance with CERN requirements.

1.4. LIST OF CRITERIA

Table 5 shows a list of properties to be tested, compiled by the working group.A comparative table, showing results for all the tested positioners, can be found in Annex 6.

Table 5: evaluation criteria

No Criteria Required value1. low steady state air consumption < 0.05 Nm3/h

10-100 Gy2. radiation hardness for a lifetime of 10 years 2

2·1012 n/cm2

3. magnetic field compatibility 0.05 T4. sensitivity to supply pressure fluctuations ≤ 0.2% / 1 bar5. repeatability ≤ 1 % FS6. precision ≤ 1 % FS7. hysteresis ≤ 1 % FS8. linearity TBC ≤ 1%

short ramping time9. step responsequick damping of overshoot

10. size, weight 2 dm3 / 1.5 kgeasy installation on valve/actuatoreasy access to interior

11. user friendliness

good visibility of display12. documentation comprehensible and detailed13. max. air pressure 7 bar a14. attachment of the positioner to the valve/actuator IEC 60534-6-1 (Namur)15. alarm features binary output as fault monitor16. deadband range 0.1 - 5 % FS17. automatic start-up quick self adjustment to valve18. remote configuration possibility to change parameters19. remote diagnosis downloading of life cycle history

failsafe in case of loss of :airelectric power

20. failure handling

communication

2 values taken from Engineering Specification "Design Parameters for Equipment Installed in the LHC", LHC ProjectDocument No. LHC-PM-ES-0002.00 rev.1.0


No Criteria Required valuecompany in business since …positioners on market since …

21. long term availability (LHC life time ~15 years)

number of positioners produced ...22. possibility to operate the valve locally local accessibility of basic functions23. external position feedback installation of positioner in 10m

distance from valve / actuator24. option to attach manometers for supply and control pressure25. dust and water protected housing IP 6526. power consumption small27. communication via field bus Profibus28. communication via analogue interface Hart29. continuous position feedback signal 4-20 mA30. electromagnetic compatibility (EMC) EN 50081-1 / EN 50082-231. mechanical vibration resistance 3g32. stroke cycles ≥ 105

33. stroke range 10 - 100mm


2. TESTS AND RESULTSA 6th positioner from Von Rohr (SreP 905) took part in the performance and magnet tests. Itrepresents the old "non digital" systems, used on cryogenic installations at CERN since many years.It serves as a reference, and the new positioners are expected to perform as well or better.There were four sets of tests performed:

1. Performance tests, static behaviour2. Performance tests, dynamic behaviour3. Tests in radiation environment4. Tests in magnetic field environment

2.1. PERFORMANCE TESTS

2.1.1. Test programThe tests were set up to determine four static parameters (mentioned as points 5-8 in Table 5), aswell as two dynamic parameters (mentioned as point 9 in Table 5).• static parameters: repeatability, precision, hysteresis and linearity• dynamic parameters: step response ramping time and damping time

2.1.2. Set-upAll positioners have been tested on the same valve/actuator/DAQ combination. For a detaileddescription, see Annex 3. The positioners have undergone a series of ramping and step cycles, inorder to determine the parameters mentioned above. The ramp and step programs were computercontrolled and lasted several hours for each positioner.

2.1.3. ResultsTable 6 and Table 7 show the results obtained. For a graphical representation, see Annex 4.

2.3.1.1. Static behaviour:

Table 6: Test results for static behaviour

repeatability precision hysteresis linearity% % % %

required value 1.0 1.0 1.0 1.0Arca 0.5 0.4 0.6 0.4Elsag-Bailey 1.2 0.4 0.6 0.6Foxboro 0.8 1.6 0.7 2.4Kämmer (prototype) 1.7 2.1 4.3 1.5Samson 0.7 0.5 0.6 0.7Von Rohr (reference) 1.3 0.7 0.8 1.3

2.3.1.2. Dynamic behaviour:

Table 7 : Test results for dynamic behaviour

ramping time damping times s

Arca 1.6 1.7Elsag-Bailey 1.7 1.9Foxboro 3.1 7.1Kämmer (prototype) 2.9 3.1Samson 1.9 1.9Von Rohr (reference) 1.8 3.5


2.1.4. EvaluationThe Arca positioner yields the best results in all tests and is always below the required values.In some of the tests, Elsag-Bailey and Samson are equal or not far behind the Arca, and still belowthe required values.The Kämmer prototype is always above the required values.The Foxboro is always (but especially for the dynamic behaviour) far above the required values.

2.2. RADIATION TESTS

2.2.1. Test programThe positioners took part in the CERN-wide COTS radiation test program organised by R. Rausch,SL/CO, see document CERN-TIS-TE/IR/98-11 / CERN-SL-CO/98-057 by R. Rausch and M.Tavlet.

2.2.2. Set-upThe positioners were tested offline, i.e. unpowered and unsupervised. Before first irradiation, inbetween the successive irradiation phases and after the last irradiation, they were submitted to ashort, standardised and computer controlled functionality test sequence. These tests can only revealif a device has obvious defects. Damage that doesn't influence the operation behaviour cannot bedetected.

2.2.3. Results

Table 8 : Test results, radiation tests

irradiation phase 1 2 3dosis / Gy 26 48 140

neutron flux / n cm-2 2*1011 5*1011 11*1011

duration / d 14 20 45Arca no symptoms one positioner

defective (A)one positioner defective+ minor malfunction (B)

Elsag-Bailey did not participate minor irregularity (C) both positionersdefective (D)

Foxboro did not participate no symptoms no symptomsKämmer did not participate both positioners

defective (E)both positioners

defective (F)

Samson did not participate no symptoms no symptomsVon Rohr d i d n o t p a r t i c i p a t e

Remarks:The following insights have been worked out in close collaboration with the manufacturers.Arca:(A) An analogue to digital converter (ADC) for the position feedback signal showed seriousdegradation. It has not been replaced after this test.(B) On the previously unharmed positioner the LCD stopped working. The previously damagedpositioner showed no further degradation.Elsag-Bailey:(C) One memory 'cell' doesn’t contain the same value as before the irradiation. This does not impedeoperation.(D) A reference voltage diode outputs 12% more than usual. This leads to micro controller failure.Problem disappeared after replacement of the diode. The inductive position sensor and its integratedtemperature element give significantly wrong readings. Problem cannot be repaired, but does notimpede operation.


Kämmer: (E) Both positioners have been diagnosed with defective optocouplers. Those have been replaced bynew ones. After that, one positioner worked fine (the other had a ground loop problem caused bythe soldering during replacement).(F) Both positioners have been diagnosed with defective optocouplers, as after the second test. Thosehave been replaced by new ones. After that, both positioners worked again, but showed problemswith the ADC for the position feedback signal.

2.2.4. EvaluationThe Foxboro and Samson did not show any signs of degradation or malfunction. It can be presumedthat no vital components have been damaged by the radiation.The Elsag-Bailey positioners' defective parts, a diode and the position sensor, are both replaceable.The diode is available as radiation hard device and the inductive position sensor can be replaced bya potentiometer. With these replacements made, the positioner should withstand higher doses ofradiation than before.The Arca positioners' defective parts are for one unit the LCD and for the other the ADC. Thedefective LCD does not impede operation and is easily exchangeable with a new one duringmaintenance. The defective ADC is integrated on the main microcontroller of the positioner. It isimpossible to run the positioner without it. With the observed degradation it is still possible tocontrol a valve, of course only in a limited way. It is highly unlikely to find a radiation hardreplacement. It is next to impossible to exchange the microcontroller during maintenance. It has tobe verified if the statistics (one defective ADC out of two tested) remain the same after additionaltests. Other positioners make use of ADCs as well.The Kämmer positioners' defective optocouplers and ADC are not easily exchangeable duringmaintenance nor is it likely to find radiation hard replacements. The optocouplers supply current tothe valves. It is impossible to run the positioner without them. The defective ADC is integrated onthe main microcontroller of the positioner. It is impossible to run the positioner without it. Theobserved degradation was significantly worse than the Arca's ADC problem.

2.3. MAGNET TESTS

2.3.1. Test programIn order to test the influences of a strong static magnetic field, the test set-up was moved into a largecoil (provided by EP/LHB), see Figure 1.

Figure 1: coil for tests in magnetic field

PCDAQ

positioner

shielding

coil

2 m

0.5 mB


2.3.2. Set-upThe same test set-up was used as for the general performance tests. The rack holding valve dummy,actuator and test positioner was put inside the gap of the coil. The DAQ was placed in a safedistance behind shielding.The coil creates a field with vertically orientated field lines and a strength of up to 1.6 T. For safetyreasons, the maximum applied field in this test was 0.05 T (500 G).The Foxboro (which had not been used before) was broken and could not be made to work in theshort timeslot available for the tests, so it was not able to participate. It has been found out since,that it was defective when delivered by the manufacturer.

2.3.3. ResultsTable 9 shows the results obtained. For a graphical representation, see Annex 5.

Table 9 : Test results for magnet tests

maximum tolerated field / Grequired value 500Arca 500Elsag-Bailey 300Foxboro did not participate

Kämmer (prototype) burned out at 500Samson 350Von Rohr (reference) 500

2.3.4. EvaluationThe tests that could be realised in the short time available allow only very qualitative results. Theycan only be regarded as a rough indication.The Arca and the Von Rohr reference tolerated a field of 500 G. The Elsag-Bailey and Samsonstopped working at around 300 G, but started working when the field fell below this level again.The Kämmer was destroyed while staying at 500 G. (A DC-DC coupler burned out.)


3. OUTLOOK

3.1. WHAT HAS STILL TO BE DONE

The radiation tests have not been conclusive. Especially when combining them with theperformance tests it becomes clear, that the positioner performing best does not seem to tolerate ahigh radiation dose, and that the positioners that do tolerate more radiation do not perform well.A delicate point is the split result for the Arca: one of the positioners had a significant degradationafter 74 Gy which stood unchanged up to 214 Gy, the other worked without any major flaws after214 Gy.In order to better judge the influence of radiation and to give the manufacturers a chance to enter thetests with slightly modified devices, a new set of positioners will take part in a second COTSirradiation campaign, planned for summer 1999. During these tests, the positioners will bepermanently powered, working and supervised. There will be space to test three to four differentpositioners (two specimens each). This campaign is organised by R. Rausch, SL/CO within theRAD working group.The following manufacturers will take part in these tests: Arca, Elsag-Bailey and Samson. IfKämmer/Bürkert can deliver their new positioner in time, it will also be tested.

• The Arca and Samson positioners will not be significantly different from the test devices in thefirst tests. Only the position sensors will be changed to external ones.

• The Elsag-Bailey will be different in a number of points:§ the radiation sensitive diode will be replaced by a radiation hard one§ the inductive internal position sensor will be replaced by a resistive external one

The new positioner from Kämmer/Bürkert will also be different in a few key points:§ it will be a two-wire device (power supply through the control cables), making optocouplers

and DC-DC couplers superfluous§ it will use piezo valves instead of solenoid valves, which increases the probability that it will

do better in the performance tests (piezo valves have smaller diameters than solenoid valves,and allow therefore a finer control of the air flow).

The Foxboro positioner will not participate in any more tests, due to its bad performance.

3.2. MARKET DEVELOPMENT

Since establishing the list of devices to be tested (see Table 4), several more became available.Some of these products look promising enough to be submitted to performance tests, e.g. Neles,Keystone. In case of good performance test results, they might participate in the radiation testprogram.


4. CONCLUSIONSFor details on the following summary, see Annex 6.

The Arca can be recommended without restriction for applications where radiation is not an issue,e.g. cryoplants at the surface. It performs very well in all respects, except in radiation environment,where it can show certain malfunctions. The behaviour in radiation environment will have to beevaluated further.The Elsag-Bailey can be recommended for applications where radiation and magnetic fields are notan issue. It performs reasonably well in most respects. Its drawbacks are its size and weight, poorlyaccessible display and a minimum deadband of only 0.3% (required are 0.1% ). With the changesforeseen, it looks also promising for radiation environment.The Foxboro cannot be recommended for any applications. It performs badly in many respects. Itsdrawbacks are high air consumption, sensitivity to supply pressure fluctuations, bad performanceconcerning precision, linearity and damping behaviour, non-adjustable deadband, very long start-uptime, rudimentary display (LEDs), non-availability of an external position sensor, non-availabilityof fieldbus communication and non-fulfilling of the EMC norm EN 50081-1.The Samson can be recommended for applications where magnetic fields are not an issue.Significant drawbacks are high air consumption, impossibility to operate the valve locally and longstart-up time. There is no improved version foreseen by Samson.The Kämmer prototype cannot be recommended for normal applications, nor for applications whereradiation or magnetic fields are an issue. It performs badly in many respects. Its drawbacks are badperformance concerning repeatability, precision, hysteresis and linearity, non-Namur attachment tovalve, non-availability of digital communication (and therefore remote configuration anddiagnosis), non-availability of a failsafe action in case of air loss, non-availability of manometers,high power consumption and a small stroke range.As the Kämmer unit is a prototype, it cannot be recommended at all. The test results show thatwithout major improvements on quite a lot of aspects it will not be possible to recommend it, evenin the future.

None of the five tested positioners is fulfilling our needs perfectly. All of them have their weakpoints. More tests in radiation environment are needed, in order to evaluate influences of this mostcritical of all parameters.


ANNEX 1

COMPARISON OF CONTROL VALVE USAGE IN LEP AND LHC

Control Valves(cryoplants and distribution system)

LEP LHC

access during beamradia-tion yes no

tunnel ü ~150underground ~120

surface ~80subtotal ~200 ~150

total ~350

access during beamradia-tion yes no

tunnel QRL ü ~1300tunnel DFB ü ~1200 *

underground ü ~300surface ~300

subtotal ~300 ~2800total ~3100

* A separate test program isrunning for mass flow controller

valves (L. Serio)

Page A 1.1.

Page A 1.1.


ANNEX 2

PHOTOS OF THE TESTED POSITIONERS

The positioners are lying on A4 pages to give a sense of scale.

Arca Elsag-Bailey

Foxboro Kämmer (prototype)

Samson Von Rohr (reference)

Page A 2.1.


ANNEX 3

DESCRIPTION OF THE VALVE / ACTUATOR / DAQ TEST SET-UP

All positioners were fitted on the same actuator/valve assembly during the tests and were connectedto the same DAQ system.

Material used:actuator:

Arca, linear single acting pneumatic actuator, 0.3 litres, pillar yoke designvalve:

1. Weka cryogenic valve, 10mm stroke2. valve simulator, in-house design, adjustable stroke

comp. air tubes:Rilsan 4/6 (4mm inner diameter)

control software:LabVIEW, in-house design, 1 analogue output channel, 2 analogue input channels, savingtimestamped data in excel format at up to 10 Hz.

control hardware:• Elonex PC, 300 MHz• Siemens CP 5412 Profibus Master Board• Wago 750-303 decentralised peripheral I/O unit (Profibus), 2 analogue outputs, 2

analogue inputs; all 4-20 mA, 12 bit resolutionposition measurement:

Megatron inductive linear position measurement, 100mm, precision < 0.1%

Profibus

PC

I/Ohardware

24 VDCpower supply

positionmeasurement

pneumaticactuator

testpositioner

filter & pressure reducer

compressedair supply

0 - 8 bar a

4-20 mA4-20 mA

LabVIEW

AOAI1

AI2

AOAI1

AI2

output input

visualisation & storage

4-20 mA optional pos. feedback

optional power supply

Page A 3.1.


ANNEX 4

GRAPHICAL RESULTS OF THE PERFORMANCE TESTS

0.5

1.2

0.8

1.7

0.7

1.3

0.0

0.5

1.0

1.5

2.0

%

Arca Elsag-Bailey Foxboro-Eckardt Kämmer(prototype)

Samson Von Rohr(reference)

repeatabilitystatic tests,

DAQ precision ~ 0.2 %

requiredvalue:

0.4 0.4

1.6

2.1

0.5

0.7

0.0

0.5

1.0

1.5

2.0

2.5

%

Arca Elsag-Bailey Foxboro-Eckardt

Kämmer(prototype)


precisionstatic tests,


requiredvalue:

Page A 4.1.


0.4

0.6

2.4

1.5

0.7

1.3

0.0

0.5

1.0

1.5

2.0

2.5

%


Kämmer(prototype)


linearitystatic tests,


requiredvalue:

0.3

0.4

1.5

1.0

0.4 0.4

0.0

0.5

1.0

1.5

%


Kämmer(prototype)


optimistic linearitystatic tests,


requiredvalue:

Page A 4.2.


0.6 0.6 0.7

4.3

0.60.8

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

%


Kämmer(prototype)


hysteresisstatic tests,


requiredvalue:

summary

0

1

2

3

4

5

6

7

8

9

10


Kämmer(prototype)


optimistic Linearity

hysteresis

precision

repeatability

static tests, DAQ precision ~ 0.2 %

Page A 4.3.


Explanation of what the two values ART and ADT represent.

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

ram

pin

g a

nd

dam

pin

g t

imes

/ s

Arca Elsag-Bailey Foxboro Kämmer(prototype)


AR

TA

DT

Step responses

Page A 4.4.


ANNEX 5

GRAPHICAL RESULTS OF THE MAGNET TESTS

500

300

500

350

500

0

50

100

150

200

250

300

350

400

450

500

G


Kämmer(prototype)


maximum tolerated field

did notparticipate

burned outat 500 G

tested field range: 0 to 500 G

Page A 5.1.


ANNEX 6

COMPARATIVE EVALUATION TABLE

Test results:No Criteria Required value Arca

827Elsag-Bailey

TZIDFoxboroSRD991

Kämmer Samson3780

Von RohrSREP905

1. low steady state airconsumption

< 0.05 Nm3/h 0.035 Nm3/h 0.025 Nm3/h 0.11 Nm3/h 0 Nm3/h 0.09 Nm3/h 0.3 Nm3/h

2. radiation hardnessfor a lifetime of 10 y

10-100 Gy2·1012 n/cm2

1 positioner ok1 impaired perf

both positio-ners defective

no symptoms both positio-ners defective

no symptoms did not par-ticipate in tests

3. magnetic fieldcompatibility

0.05 T > 0.05 T 0.03 T no values < 0.05 T 0.035 T > 0.05 T

4. sensitivity to supplypressure fluctuations

≤ 0.2% / 1 bar < 0.05% / 1 bar < 0.1% / 1 bar 0.1% / 1 barpeaks up to 3%

< 0.1% / 1 bar 0.1% / 1 bar 0.2% / 1 bar

5. repeatability ≤ 1 % FS 0.5 % 1.2 % 0.8 % 1.7 % 0.7 % 1.3 %6. precision ≤ 1 % FS 0.4 % 0.4 % 1.6 % 2.1 % 0.5 % 0.7 %7. hysteresis ≤ 1 % FS 0.6 % 0.6 % 0.7 % 4.3 % 0.6 % 0.8 %8. linearity (TBC) ≤ 1% 0.4 % 0.6 % 2.4 % 1.5 % 0.7 % 1.3 %9. step response short ramping time

short damping time1.6 s1.7 s

1.7 s1.9 s

3.1 s7.1 s

2.9 s3.1 s

1.9 s1.9 s

1.8 s3.5 s

10. size, weight 2 dm3 / 1.5 kg 2 dm3 / 1.3 kg 4 dm3 / 2.9 kg 3 dm3 / 1.7 kg 1.2 dm3 / 1 kg 1.5 dm3 /1.3 kg 2 dm3 / 1.5 kg11. user friendliness easy installation

access to interiorvisibility of display

easyeasygood

easydifficultbad

easydifficultbad

easyeasyeasy

easydifficultno display

difficultdifficultno display

12. documentation comprsble, detailed good meagre bad good medium medium13. max. air pressure 7 bar a 8 bar a 7 bar a 7 bar a 7 bar a 7 bar a 7 bar a14. attachment of the

positioner to thevalve/actuator

IEC 60534-6-1(Namur)

conform conform conform not conform conform conform

15. alarm features binary output asfault monitor

programmablebinary output

binary alarmoutput



binary alarmoutput

not available

Shaded boxes show disadvantageous points.

Page A 6.1.

Page A 6.1.


No Criteria Required value Arca827

Elsag-BaileyTZID

FoxboroSRD991

Kämmer Samson3780

Von RohrSREP905

16. deadband range 0.1% - 5 % FS 0.1% - 10% 0.3% - 10% not adjustable 0.1% - 5% 0.1% - 10% not adjustable17. automatic start-up quick selfadjust-

ment to valve2 to 3 minutes 2 to 3 minutes 15 to 20

minutes1 to 2 minutes 4 to 5 minutes not available

18. remote configuration changing ofparameters

available available available not available available not available

19. remote diagnosis downloading oflife cycle history

available available available not available available not available

20. failure handling failsafe in case ofloss of : airelectric powercommunication

failsafefailsafefailsafe



fail freezefailsafefailsafe



21. special features built-in PIDcontroller

Page A 6.2.

Page A 6.2.


Points looked up in datasheets:No Criteria Required Arca

827Elsag-Bailey

TZIDFoxboroSRD991

Kämmer Samson3780

Von RohrSREP905

22. long term availability(LHC life time ~15y)

in pos. business:pos. on market:number produced:

since 1965since 08/1997> 10'000

since 1980since 1994~ 15'000

since 1960since 1996> 10'000

since 1960 1

since 03/1996> 10'000

since 1950since 1995a few thousand

since 1960since 1991~ 1000

23. possibility to operatethe valve locally

local accessibilityof most functions

LCD and3 buttons

LCD, 3 buttonsand 1 switch

5 LEDs and3 buttons

LCD and3 buttons

not possible not possible

24. external positionfeedback

installation in10m distance

10m 10m not available 10m 20m 10m

25. option to attachmanometers

for supply andcontrol pressure

available available available not available available available

26. dust and waterprotected housing

IP 65 IP 65 IP 65 IP 65 IP 65 IP 54 (IP 65 asoption)

IP 54

27. power consumption small < 0.1 W < 0.1 W < 0.1 W < 10 W < 0.1 W < 0.1 W28. communication via

field busProfibus Profibus PA Profibus PA not available not available Profibus PA not available

29. communication viaanalogue interface

Hart Hart Hart Hart not available Hart not available

30. continuous positionfeedback signal

4-20 mA 4-20 mA 4-20 mA 4-20 mA 4-20 mA 4-20 mA not available

31. electromagneticcompatibility (EMC)

EN 50081-1EN 50082-2

EN 50081-1EN 50082-2

EN 50081-1EN 50082-2 EN 50082-2

EN 50081-1EN 50082-2

EN 50081EN 50082

IEC 801-1…5

32. mechanical vibrationresistance

3g 10g 10g 2g 4g 4g 4g

33. stroke cycles ≥ 105 no dataavailable

no dataavailable

no dataavailable

no dataavailable

> 105 no dataavailable

34. stroke range 10 - 100mm 3mm - 130mm 10mm-100mm 8mm - 100mm 10mm - 80mm 7.5mm-120mm 10mm-100mm

1 Kämmer is in the positioner business since a long time. The prototype has been developed by Bürkert, who are in the business since 1996.

Page A 6.3.

Page A 6.3.

evaluation of electro pneumatic valve positioners...

Documents