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EB 8389 EN 

 75 

Tests

5.4  Partial stroke test (PST)

The partial stroke test (PST) is particularly 
suitable for the status-oriented detection of 
malfunctions in pneumatic shut-off valves. As 
a result, the probability of failure on demand 
(PFD) can be reduced and it may be possible 
to extend maintenance intervals.
A shut-off valve normally in its end position 
can be prevented from seizing up or getting 
jammed. The initial breakaway torque must 

first be overcome after the valve starts to 

move from its end position. The initial break-
away torque depends on the plug/seat seal, 
deposits on the plug, the process medium 
and friction at the valve trim. After the initial 
breakaway torque has been overcome, it 
can be assumed that the valve is able to 
close completely.

The recording of the test results additionally 
allows an analysis of the dynamic control re-
sponse.
The partial stroke test can be performed 
once (test immediately started) or, with an 
on/off valve in automatic mode, regularly 
(time-controlled), provided the start condi-

tions are met (see page 73 and 
page 74):

 

A control valve is in the manual mode.

 

An on/off valve is in the manual or auto-
matic mode. In automatic mode, the test 
is only started when the Set point w is 
greater than the 'Limit fail-safe position' 
(Code 49 - h2).

The following listed parameters are activated 
while the partial stroke test is being per-
formed:

Fig. 12: 

Diagnosis > Tests > Partial stroke test

Summary of Contents for TROVIS 3730-3

Page 1: ...ions EB 8389 EN Firmware version Edition August 2017 Series 3730 and 3731 Types 3730 2 3730 3 3730 4 and 3730 5 as well as Types 3731 3 and 3731 5 Electropneumatic Positioners EXPERTplus Valve Diagnos...

Page 2: ...partment aftersalesservice samson de The mounting and operating instructions for the devices are included in the scope of delivery The latest documentation is available on our website www samson de Pr...

Page 3: ...3 2 1 Condensed state at the fault alarm output 22 3 3 Logging 22 4 Statistical information 25 4 1 Open close on off valve 27 4 1 1 On off diagnosis 28 4 1 2 Analysis and monitoring 29 4 1 3 Resetting...

Page 4: ...hysteresis 67 5 2 1 Analysis and monitoring 68 5 2 2 Resetting single status messages 69 5 3 Static characteristic 70 5 3 1 Resetting single status messages 71 5 4 Partial stroke test PST 75 5 4 1 Sta...

Page 5: ...pe 3731 3 106 8 2 Type 3730 4 107 8 3 Types 3730 5 and 3731 5 107 9 Appendix 109 9 1 Code list 109 9 1 1 PROFIBUS parameter Type 3730 4 115 9 1 2 FOUNDATION fieldbus parameters Type 3730 5 Type 3731 5...

Page 6: ...6 EB 8389 EN...

Page 7: ...ot follow the set point Instead it is moved according to the test specifications Therefore the tests can only be started when the conditions in the plant allow it Qualifications of operating personnel...

Page 8: ...hat operating personnel or third persons are not exposed to any danger Responsibilities of operating personnel Operating personnel must read and understand these operating instructions as well as the...

Page 9: ...Settings for the EXPERTplus valve diagnostics can be made in the TROVIS VIEW software In online mode of this software the configuration and parameter settings take effect immediately in the connected...

Page 10: ...ection 7 T No configuration required for monitoring Valve position x histogram Section 4 3 B Set point devia tion histogram Section 4 4 B Cycle counter histogram Section 4 5 B Trend of travel end posi...

Page 11: ...terface Refer to the mounting and operating instruc tions of the positioner for a list of all param eters that can be changed at the positioner see Referenced documentation on page 8 2 2 Operation usi...

Page 12: ...positioner adapts itself opti mally to the friction conditions and the signal pressure required by the control valve The positioner can be initialized using one of the following initialization modes m...

Page 13: ...m steady state d1 Reference of drive signal diagram hysteresis d2 Reference of drive signal diagram steady state d1 Reference of drive signal diagram hysteresis d2 All reference values are overwritten...

Page 14: ...rive signal NOTICE diagram hysteresis test d2 See section 5 2 and section 5 1 The valve moves through its working range during the reference test The reference test cannot be performed if the position...

Page 15: ...the plant allow it e g plant shut down or service work in the workshop For NOTICE reasons of safety these tests except for par tial stroke testing can only be performed in the manual mode An active t...

Page 16: ...8389 EN Operation nating sequence on the display See sec tion 4 1 2 5 2 Analysis Table 1 shows the diagnostic functions and their statements on the condition of the valve depending on the application...

Page 17: ...nge Connection positioner valve Inner seat leakage Average set point deviation 4 4 page 40 Cycle counter histogram Stuffing box external leakage Dynamic stress factor 4 5 page 45 Drive signal diagram...

Page 18: ...page 70 Partial stroke test PST Overshooting Dead time T63 T98 Types 3730 2 4 5 Types 3731 3 5 Rise time Settling time 5 4 page 75 Full stroke test FST Overshooting Dead time T63 T98 Types 3730 2 4 5...

Page 19: ...densed state and temperature Settings Positioner Error control In formation on total valve travel with con figurable limits Positioner Start up Initialization List of initialization errors which are a...

Page 20: ...nosis Status messages as well as Diagno sis Status messages Extended 3 1 1 Resetting status mes sages When a status message is generated you should first locate the source of the fault and take action...

Page 21: ...e deleted The positioner must be re initialized after resetting Before mounting the positioner on a new control valve perform a reset by activating Code 36 Std and re initialize the position er Operat...

Page 22: ...alarm output is activated 2 Settings Positioner Error control Fault alarm at condensed state Function check Code 32 Yes 3 Fault alarm at condensed state Mainte nance required Code 33 Yes Note 3 3 Log...

Page 23: ...1 Parameters YES NO YES Measured values YES YES YES Data logger 2 3 NO YES YES Valve position x histogram YES YES YES Short term monitoring YES YES YES Set point deviation e histogram YES YES YES Shor...

Page 24: ...NO NO YES Repetition test 1 3 YES NO YES Short term monitoring 1 3 NO YES YES Long term monitoring 1 3 NO YES YES Sound level monitoring 1 3 NO YES YES 1 Not Type 3730 4 2 Not Type 3730 5 1 6x 3 Not...

Page 25: ...d and analyzed by the monitoring functions in Statistical information In addition a back ground hysteresis test can detect any chang es in friction The monitoring functions in Statistical infor mation...

Page 26: ...rameters for partial stroke test see section 5 4 On off diagnosis Discrete set point analysis PST x w t s t 6 s 25 50 x w t s First analysis after defining parameters Reference PROCESS Breakaway time...

Page 27: ...rts the valve moves to the fail safe position If the set point increases and exceeds Limit op erating point the valve moves to the Oper ating point The valve moves back to the fail safe position 0 in...

Page 28: ...h1 1 0 0 to 100 100 Limit fail safe position Code 49 h2 1 0 0 to 20 0 12 5 Limit operating point Code 49 h5 1 55 0 to 100 0 75 0 3 Diagnosis Tests Partial stroke test See section 5 4 1 Not Type 3730...

Page 29: ...alue by the amount entered in Limit value time analysis The current Valve end position rising differs from the reference value by the amount entered in Limit value travel analysis The current Valve en...

Page 30: ...B DO 3 Trigger value Trigger band Trigger edge Trigger value Trigger band Trigger edge 1 Types 3730 2 3 Type 3731 3 2 Types 3730 4 5 3 Type 3730 5 100 measured values w x e y Pre trigger time Scan rat...

Page 31: ...the positioner Failure of power supply of the external so lenoid valve 4 2 1 Permanent data logging 3730 2 3730 3 3731 3 3730 4 3730 5 3731 5 1 1 Function available in firmware 1 5x and lower The meas...

Page 32: ...so leads to the mea suring values before the triggering event for the time selected being included in the 100 measured values per measured variable The Pre trigger time may include the value 100 x Sca...

Page 33: ...r band and Trigger edge are met Trigger edge Low signal falling edge bottom band exit Bottom band limit Trigger value trigger band Trigger value Trigger band w x y e The conditions for starting a trig...

Page 34: ...set point deviation 0 0 to 10000 0 1 s 99 0 1 s drive signal Trigger band 0 0 to 100 0 99 0 set point valve position set point deviation 0 0 to 10000 0 1 s 99 0 1 s drive signal Pre trigger time 0 0...

Page 35: ...gger Selection Trigger 2 Trigger status Start trigger via set point int sol valve forced venting Trigger value 0 0 to 100 0 99 0 Trigger band 0 0 to 100 0 99 0 Pre trigger time 0 0 s to 100 x Scan rat...

Page 36: ...ction Trigger 2 Trigger status Start trigger via discrete input 1 or start trigger via discrete input 2 Pre trigger time 0 0 s to 100 x Scan rate 0 0 s Trigger edge Low signal High signal 3 Scan rate...

Page 37: ...sition classes The distribu tion showing how often the sound level oc curred within a valve position class is shown in a bar graph The Average value x long indicates the average class assignment of th...

Page 38: ...osing position Mostly near max opening Mostly closing position Mostly max opening Type 3730 5 1 6x and Type 3731 5 2 Settings Positioner Diagnosis configuration Classification Shifting working range 1...

Page 39: ...mmand Reset Travel histogram x This command resets all diagnostic parameters and measured da ta of the histogram and the short term moni toring By selecting and executing the command Reset Travel hist...

Page 40: ...ion showing how often the set point deviation remained within a class is shown in a bar graph The Average value e long indicates the average class assignment of the set point deviation over the Observ...

Page 41: ...and Type 3731 3 2 Settings Positioner Error control Classification report Extended Limit working range Down Up Modification impossible jammed Connection positioner valve No optimum travel transmissio...

Page 42: ...eakage and Limit working range messages can be reset by selecting and executing the command Reset Set point deviation histogram e or Reset Set point deviation histogram e Short term The Connection pos...

Page 43: ......

Page 44: ...rhaps soon expected PROCESS Determining the cycle spans t s x 1 2 3 4 Determining the cycle height t s x 1 2 3 4 Dynamic stress factor Dynamic stress factor Dynamic stress factor 90 Dynamic stress fac...

Page 45: ...changes direction again The positioner records the cycle height when the Stuffing box stem seal setting is set to Bellows seal The cycle height is the travel performed between two changes in direc ti...

Page 46: ...cation External leakage 1 Setting only with Stuffing box Other 4 5 1 Analysis and monitoring Analysis of the histogram starts directly af ter the change to manual or automatic mode The load on the bel...

Page 47: ...cuting the Reset Cycle counter histogram command all diagnostic parameters and measured data of the histo gram and the short term monitoring as well as the Dynamic stress factor are reset By selecting...

Page 48: ...springs Leakage pneumatics Perhaps modified not enough Working at full capacity Perhaps too large existing PROCESS Working at full capacity Status classification NE 107 logged by operating hours count...

Page 49: ...ackground re gardless of the operating mode selected Da ta logging does not need to be activated The positioner records the valve position x and its associated drive signal y in closed loop operation...

Page 50: ...ctuator is mounted on the valve 2 No booster is mounted on the control valve 3 The valve operates as a control valve 4 A reference test has been performed see section 2 4 1 1 Settings Identification P...

Page 51: ...positioner generates the Air supply message with the selected status classification The drive signal shifts downwards with a smaller gradient than in the reference graph pinpointing to a reduced sprin...

Page 52: ...ately User defined Min time distance from test Cancellation condition Tolerance band of hysteresis Status classification NE 107 Friction PROCESS Much higher lower over whole range Much higher lower ov...

Page 53: ...eresis allows an analysis in the change of the friction forces in Types 3730 2 3 and Types 3731 3 5 Data are recorded after the hysteresis test is activated A single test can be performed im mediately...

Page 54: ...t the top or bottom limit of the working range the po sitioner generates the message Test infor mation Test at operating point not possi ble Short term monitoring To provide a short term trend the las...

Page 55: ...position x leaves the Toler ance band of hysteresis during the test the test is immediately canceled and the positioner returns to closed loop opera tion If a change in set point w occurs which is gr...

Page 56: ...mmand Reset Drive signal diagram hysteresis or Reset Drive signal diagram hysteresis short term By selecting and executing the command Reset Drive signal diagram hysteresis all the measured data of th...

Page 57: ......

Page 58: ...d Section 2 4 1 NO YES First zero point Reference Subsequent zero calibration over Code 6 ZP Zero calibra tion ZP shift monotone down up average above below reference NP alternate above below referenc...

Page 59: ...the valve position x and the drive signal y together with the time stamp by the operating hours counter when the valve moves to the lower end position The new recorded valve posi tion is compared to...

Page 60: ...t monotone up average be low reference Zero point alternate average below reference Type 3730 5 1 6x and Type 3731 5 3 Settings Positioner Diagnosis configuration Classification Observing end position...

Page 61: ...est is being per formed Therefore it is important to check before starting a test whether the conditions in the plant or process allow the valve to move through its working range The tests provide a t...

Page 62: ...est Reference Start test Test analysis Air supply Perhaps modified Perhaps not enough Working at full capacity Actuator springs Perhaps spring stiffness reduced bias reduced Working at full capacity L...

Page 63: ...test the valve moves to various fixed valve positions distributed over the working range of the valve The drive signal y is measured for each valve position x and compared with the reference graph Th...

Page 64: ...matics Perhaps existing TEST Perhaps too large TEST Actuator springs Spring stiffness may be reduced spring fail ure TEST Perhaps bias reduced TEST Working at full capacity TEST Type 3730 5 1 6x and T...

Page 65: ...graph and then starts to rise almost steadily This pinpoints to a supply pressure that is in sufficient for the valve to move through its entire working range The positioner generates the Air supply m...

Page 66: ...07 Friction MANUAL MODE TEST Start test Reference test completed see section 2 4 1 NO YES First test Reference Start test Test analysis Friction Much higher lower over whole range Much higher lower ov...

Page 67: ...of the valve After moving to each valve position a ramp movement changing the valve travel by less than 1 is performed The change in drive signal y is measured for each valve position x and compared w...

Page 68: ...band of hysteresis 1 0 to 5 4 Diagnosis Tests Drive signal diagram hysteresis Start test 1 Types 3730 4 5 and Type 3731 5 Operation Operating mode Positioner AO TRD 2 Types 3730 4 5 1 5x two single pa...

Page 69: ...th time that the test is canceled the time entered in Min time distance from test is kept again If the analysis of the hysteresis pinpoints Friction the positioner generates a corre sponding status me...

Page 70: ...ng and the defined test range The ascendent and descendent are plotted within the test range The response of the valve position x to the change in set point w is plotted in a graph The dead band is an...

Page 71: ...Number of measurement values until turn back 1 to 50 50 3 Start test 1 Types 3730 4 5 and Type 3731 5 Operation Operating mode Positioner AO TRD Cancel the test by right clicking Stop test and select...

Page 72: ...the max breakaway time The valve position exceeds x control value The drive signal exceeds the comparative value given by the delta y monitoring The valve position deviation exceeds the PST tolerance...

Page 73: ...PST Man PST Auto t 6 s 25 50 x w t s PST not possible PST not possible PST not possible PST possible 1 3 4 1 2 3 4 1 2 3 1 3 Fail safe action of actuator fail safe position operating mode Operating p...

Page 74: ...PST not possible PST 1 3 possible PST 1 2 3 possible Fail safe action of actuator fail safe position operating mode Operating point valve position according to set point 1 PST starts once 2 PST starts...

Page 75: ...dium and friction at the valve trim After the initial breakaway torque has been overcome it can be assumed that the valve is able to close completely The recording of the test results additionally all...

Page 76: ...e Settling time before test start has elapsed Starting from the Step start the valve moves to Step end The valve remains in this position for the time defined by the Delay time after step before perfo...

Page 77: ...y result in overshooting To prevent this the drive signal y can be monitored and the test canceled in the event that an error is de tected delta y monitoring value The test is canceled as soon as the...

Page 78: ...meters 1 Define parameters for partial stroke test See Note concerning setting the PST di agnostic parameters on page 79 2 Define parameters for cancellation con ditions 3 Select classification for st...

Page 79: ...time Code 49 A3 1 h to 2345 d NOTICE The positioner is write protected when tests are performed according to a schedule on site operation and operating software Code 0 reading OC and PST in alternat...

Page 80: ...Tolerance limit of step response for the partial stroke test to start The test and its cancellation are described in section 5 4 while the test assessment is de scribed in section 5 4 3 5 4 2 Start tr...

Page 81: ...e step height Dead time s T63 s T98 s Rise time s Settling time s Analysis of measured data ramp test Overshoot relative to the step height The results of the first partial stroke test are used as the...

Page 82: ...ultimate test is deleted when another test is performed Operation Reset Reset PST 5 4 5 Step response The dynamic performance of the control valve can be tested by plotting its step re sponse The step...

Page 83: ...EB 8389 EN 83...

Page 84: ...s No 1 Yes Ramp time rising Ramp time falling Cancellation condition Max test duration user defined Status classification PST FST Maximum test duration or allowed time to reach full closed position ex...

Page 85: ...ves through its entire working range The first step ends in the fail safe position As a result the second step starts from the fail safe position The change in travel can be performed ei ther in steps...

Page 86: ...g cancellation con ditions is fulfilled Max test duration The test is canceled when the maximum permissible test du ration is reached Max breakaway time Types 3730 4 5 only The test is canceled when t...

Page 87: ...er Current test Defining parameters 1 Switch to manual mode 2 Define parameters for full stroke test See Note concerning setting the FST diagnos tic parameters on page 88 3 Configure the cancellation...

Page 88: ...mum transit time close Code 41 deter mined during initialization The Ramp time falling must be greater than the corresponding value for Mini mum transit time open Code 41 deter mined during initializa...

Page 89: ...e selected status classifi cation Extended diagnosis Code 79 is activated regardless of the status classifica tion Diagnosis Status messages Extended PST FST The No test available status remains activ...

Page 90: ...l so be transferred using a universal com mand Depending on the positioner the dynamic HART variables can be assigned by the DD or in TROVIS VIEW Settings Operation unit as shown in Table 4 Settings O...

Page 91: ...Set point deviation e Absolute total valve travel Absolute total valve travel Binary input status 0 Not active 1 Active 255 Internal solenoid valve forced venting status 0 De energized 1 Energized 2...

Page 92: ...uccessful Reset Reference test Reset Repetition test Alarm settings Select alarm limit Status classification NE 107 Alarm limits 1 2 3 Recommended 10 dB 15 dB 25 dB Alarm limit 2 exceeded Alarm limit...

Page 93: ...exceeds one of the alarm limits Requirements for using the seat leakage detection 1 A leakage sensor is attached to the valve Refer to the standard mounting and operating instructions of the posi tio...

Page 94: ...1 1 While the reference test is running the pa rameters listed below are automatically de activated Enable set point cutoff decrease Activation of ramp function Phase 1 The valve moves to eleven defin...

Page 95: ...ence test is successfully completed If the Activation level is not reached after the valve has moved to all eleven newly de fined points then the change in sound pres sure level is too low In this cas...

Page 96: ...Measured point 1 to Measured point 11 The valve moves to the user defined points in steps of 0 1 Measuring points must be rounded up to two deci mal places User defined points can be saved for other...

Page 97: ...ted up If it is not possible to perform the repetition test the user defined alarm limits can be en tered see section 7 1 2 2 While the repetition test is running the pa rameters listed below are auto...

Page 98: ...is subdi vided into eleven new measured points Each measured point is located at a distance of 0 03 to the next point The valve moves to the new points one after the other After reaching a measured p...

Page 99: ...3 to 255 dB 10 dB Measured point change 0 00 to 100 00 1 0 00 2 0 10 3 0 20 4 0 03 5 0 04 6 0 05 7 0 06 8 0 07 9 0 08 10 0 09 11 1 00 3 Start repetition test 2 Type 3730 5 Operation Operating mode Po...

Page 100: ...fter connecting the leakage sensor and performing the reference and repetition tests the positioner is able to pinpoint any seat leakage To do this it records the sound level in closed loop operation...

Page 101: ...during long term monitoring see section 7 3 is used for monitoring Fig 18 Tight closing event 1 to Tight closing event 31 with all sound levels The No alarm release setting deactivates the alarm func...

Page 102: ...with status classi fication selected for Alarm limit 3 exceed ed Diagnosis Status messages Extended Inner seat leakage 7 1 2 4 Resetting single status messages The repetition test diagnostic paramete...

Page 103: ...sound level and last four recorded sound levels If this mean value deviates from the last mean value in short term monitoring by the amount entered in Activation point short term it is saved as the ne...

Page 104: ...level trend over a long pe riod of time the long term monitoring con tains all the mean values saved in the short term monitoring since the last reset Long term average The average sound level calcul...

Page 105: ...ions classes The distribu tion showing how often the sound level oc curred within a valve position class is shown in a bar graph Data are recorded in the background re gardless of the operating mode s...

Page 106: ...anual mode or vice versa This function is not performed if the positioner is in the fail safe position mode Start data logger Activation of the binary input causes the data logger to start see section...

Page 107: ...ntermediate position Condensed state In this setting the current condensed state according to NAMUR Recommen dation NE 107 is issued over OUT_D The status messages are assigned to the discrete value a...

Page 108: ...2 Maintenance demanded 3 Maintenance alarm 7 Function check Condensed state and VST The positioner starts a single partial stroke test The test is performed using the settings in Code 49 d2 to Code 4...

Page 109: ...ns performed since the last initial ization Read only d4 No of initializations The total number of initializations that have been performed since the last reset Read only d5 Zero limit 0 0 to 100 0 of...

Page 110: ...et diAG 0 to 365 days After an adjustable time period the diagnosis data are reset auto matically according to the settings in Code 36 diAG Example A start up behavior of the plant which is untypical...

Page 111: ...value 1 s The y monitoring reference value applies to the adjusted step values Code 49 d2 and Code 49 d3 and for the selected ramp times Code 49 d5 and Code 49 d6 The y monitoring reference value must...

Page 112: ...es a sensible value that is not to be undercut if possible d6 Ramp time falling 0 to 9999 s 15 s 1 2 45 s 4 5 600 s 3 Ramp time for 100 to 0 travel falling of ramp function Initialization provides a s...

Page 113: ...trol No YES Activates or deactivates PST tolerance band monitoring E6 PST tolerance band 0 1 to 100 0 5 0 The test is automatically canceled as soon as the Step end Code 49 d3 exceeds this percentage...

Page 114: ...ending on the adjusted application type the positioner responds differently in automatic mode and there are differences in the diag nostic functions h1 Operating point 0 0 to 100 0 of the valve positi...

Page 115: ...s the difference at which a message is gen erated h8 Limit value time analy sis 0 1 to 100 0 of the valve position 0 3 Types 3730 2 3 and Type 3731 3 only Travel limit for difference between reference...

Page 116: ...ed 1 wait_cfg 2 wait_prm 3 data_exchg AO Function Block A A0 Target mode Desired operating mode 1 A1 Actual mode Current operating mode 1 A2 SP value Set point reference variable and its status A3 SP...

Page 117: ...e Current valve position FVR and its status t9 AO Final_Position_ Value State Resource Block S S0 Resource target mode Desired operating mode 1 S1 Resource actual mode Current operating mode 1 DI1 Fun...

Page 118: ...iscrete output variable and its status L7 DI2 Fb OUT_D State L8 DI2 FSAFE_VAL_D Default when the sensor registers an error L9 Simulate Simulation 1 Actual desired operating mode Operating mode Indicat...

Page 119: ...ue Manipulated variable output value and its status A7 Out status A8 Block error Current block error PID Function Block PID P0 Target mode Target operating mode P1 Actual mode Current operating mode P...

Page 120: ...t operating mode S1 Resource actual mode Current operating mode S2 Resource block error Current block error DI1 Function Block I0 Target Mode DI1 Target operating mode I1 Actual Mode DI1 Current opera...

Page 121: ...more than 5 Autocorrection Code 59 Data section error in position er Fatal error Code 60 Error detected in safety relevant data Possible cause EMC disturbances The valve is moved to fail safe positio...

Page 122: ...ion Code 67 Hardware error has occurred Confirm error If this is not possible return positioner to SAMSON for repair Program load error Code 77 A program has been loaded that does match the positioner...

Page 123: ...de Code 6 Positioner detected during initialization that actuator permits no emergency control mode without feedback In case of a travel sensing error positioner vents Output or A1 in double acting ac...

Page 124: ...n 4 6 2 section 5 1 2 Shifting working range The working range has shifted towards CLOSED or max OPEN position Rethink the working range Section 4 3 2 Leakage pneumatics A leak in the pneumatics exist...

Page 125: ...or springs The spring stiffness is re duced spring failure Reduced spring compres sion The actuator springs are working at full capacity Check actuator springs Section 4 6 2 section 5 1 2 Inner seat l...

Page 126: ...volatile memory Saved directly after they change Saved cyclically every 24 h Statistical information Open Close Limit value time analysis Limit value travel analysis Reference assessment Assessment D...

Page 127: ...n Number of step responses Activation x control x control value Activation delta y monitoring del ta y monitoring value Activation PST toler ance band control PST tolerance band delta y monitoring ref...

Page 128: ...response 2 0 WE Activation of the ramp function Yes WE Ramp time rising 900 s Ramp time falling 900 s Settling time before test start 10 s Delay time after step 4 0 s Scan rate Min recommended scan r...

Page 129: ...EB 8389 EN 129 Appendix Fig 21 Full stroke test to determine the ramp times in the partial stroke test The valve position follows the set point closely in the example...

Page 130: ...130 EB 8389 EN...

Page 131: ...e x Valve position x0 Valve position when the valve is tightly shut w Set point reference variable ATC Air to close ATO Air to open BI Binary input BSZ Operating hours counter FST Full stroke test INI...

Page 132: ...SAMSON AG MESS UND REGELTECHNIK Weism llerstra e 3 60314 Frankfurt am Main Germany Phone 49 69 4009 0 Fax 49 69 4009 1507 samson samson de www samson de EB 8389 EN 2018 01 08 English...

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