Kuyedzwa kweuchapupu chikamu chakakosha chekuchengetedza kuchengetedzeka kwemasisitimu edu ekuchengetedza (SIS) uye masisitimu ane chekuita nekuchengetedzeka (semuenzaniso maalarm akakosha, masisitimu emoto negasi, masisitimu ekubatanidza masisitimu ane zvishandiso, nezvimwewo). Kuyedzwa kweuchapupu kuyedzwa kwenguva nenguva kwekuona kutadza kune njodzi, kuyedza mashandiro ane chekuita nekuchengetedzeka (semuenzaniso kugadzirisazve, kuyambuka, maalarm, kuongororwa, kuvharwa nemaoko, nezvimwewo), uye kuona kuti sisitimu inosangana nezvinodiwa nekambani nedzekunze. Mhedzisiro yekuyedzwa kweuchapupu zvakare chiyero chekushanda kwechirongwa cheSIS chekuchengetedza uye kuvimbika kwesisitimu.
Maitiro ekuyedza humbowo anosanganisira matanho ekuyedza kubva pakuwana mapemiti, kugadzira zviziviso uye kubvisa sisitimu pabasa rekuyedza kusvika pakuona kuti bvunzo dzakakwana, kunyora bvunzo yehumbowo nemigumisiro yayo, kudzosera sisitimu pabasa, uye kuongorora mhinduro dzemiedzo yazvino uye mhinduro dzemiedzo yapfuura yehumbowo.
ANSI/ISA/IEC 61511-1, Chikamu 16, chinosanganisira kuyedzwa kweSIS proof. ISA technical report TR84.00.03 – “Mechanical Integrity of Safety Instrumented Systems (SIS),” inovhara kuyedzwa kweproof uye parizvino iri kugadziriswa neshanduro itsva inotarisirwa kubuda munguva pfupi iri kutevera. ISA technical report TR96.05.02 – “In-situ Proof Testing of Automated Valves” iri kugadzirwa parizvino.
Mushumo weHSE weUK CRR 428/2002 - "Nheyo dzekuongorora humbowo hwemasisitimu ekuchengetedza muindasitiri yemakemikari" dzinopa ruzivo pamusoro pekuongorora humbowo uye zviri kuitwa nemakambani muUK.
Maitiro ekuedza humbowo akavakirwa pakuongorora nzira dzinozivikanwa dzekukundikana kwengozi dzechikamu chimwe nechimwe chiri munzira yekufamba yesafety instrumented function (SIF), mashandiro eSIF sesystem, uye maitiro (uye kana) ekuedza nzira yekukundikana kwengozi. Kugadzira maitiro kunofanirwa kutanga muchikamu chekugadzira SIF nekugadzira sisitimu, kusarudzwa kwezvikamu, uye kuona kuti bvunzo yekusimbisa riini uye sei. Zvishandiso zveSIS zvine mwero wakasiyana wekuoma kwekuongorora humbowo izvo zvinofanirwa kufungwa nezvazvo mukugadzira, kushanda uye kugadzirisa kweSIF. Semuenzaniso, mita dze orifice uye zvinotumira pressure zviri nyore kuyedza kupfuura Coriolis mass flowmeters, mag metres kana through-the-air radar level sensors. Kushandiswa uye dhizaini yevharuvhu zvinogonawo kukanganisa kukwana kwebvunzo yekudzivirira vharuvhu kuona kuti kukundikana kune njodzi uye kunotanga nekuda kwekuora, plugging kana kukundikana kunoenderana nenguva hakutungamiriri kukukundikana kukuru mukati menguva yebvunzo yakasarudzwa.
Kunyange zvazvo maitiro ekuyedza humbowo achiwanzogadzirwa panguva yeSIF engineering phase, anofanirawo kuongororwa neSIS Technical Authority, Operations uye mainjiniya emidziyo vachange vachiita bvunzo. Ongororo yekuchengetedzwa kwebasa (JSA) inofanirawo kuitwa. Zvakakosha kuwana mvumo kubva kufekitori pamusoro pekuti ndeapi bvunzo dzichaitwa uye riini, uye kugona kwadzo kwemuviri nekuchengetedzeka. Semuenzaniso, hazvina zvazvinobatsira kutsanangura bvunzo yechikamu kana boka reOperations risingabvumirani kuzviita. Zvinokurudzirwawo kuti maitiro ekuyedza humbowo aongororwe nenyanzvi yakazvimiririra yenyaya (SME). Kuyedza kwakajairika kunodiwa kuti bvunzo yehumbowo ishande zvakanaka kunoratidzwa muMufananidzo 1.
Zvinodiwa pakuedza kuchengetedzwa kwebasa rose Mufananidzo 1: Tsanangudzo yekuedza kudzivirirwa kwebasa rose rekuchengetedza (SIF) nehurongwa hwayo hwekuchengetedzwa kwebasa (SIS) inofanira kutsanangura kana kutaura nezvematanho akatevedzana kubva pakugadzirira bvunzo uye maitiro ekuedza kusvika kuzviziviso nemagwaro.
Mufananidzo 1: Tsanangudzo yakazara yekuedza proof function ye safety instrumented function (SIF) uye safety instrumented system yayo (SIS) inofanira kutsanangura kana kutaura nezvematanho akatevedzana kubva pakugadzirira bvunzo uye maitiro ebvunzo kusvika kuzviziviso nemagwaro.
Kuongororwa kweuchapupu chiitiko chakarongwa chekugadzirisa chinofanira kuitwa nevashandi vane hunyanzvi vakadzidziswa bvunzo dzeSIS, maitiro ekuongorora, uye SIS loops dzavachaedza. Panofanira kuva nekuongororwa kwemaitiro acho vasati vaita bvunzo yekutanga yekuongorora, uye mhinduro kuSIS Technical Authority mushure mezvo kuti vagadzirise kana kugadzirisa.
Kune nzira mbiri huru dzekukundikana (dzakachengeteka kana dzine njodzi), dzakakamurwa kuita nzira ina—dzine njodzi dzisingaonekwe, dzine njodzi dzinoonekwa (nekuongorora), dzakachengeteka dzisingaonekwe uye dzakachengeteka dzinoonekwa. Mashoko ekukundikana asina njodzi uye ane njodzi anoshandiswa zvakafanana muchinyorwa chino.
Mukuongorora kweSIF proof, tinonyanya kufarira nzira dzine njodzi dzekukundikana dzisingaonekwe, asi kana paine nzira dzekuongorora dzevashandisi dzinoona kukundikana kune njodzi, nzira idzi dzekuongorora dzinofanira kuongororwa humbowo. Ziva kuti kusiyana nekuongorora kwevashandisi, nzira dzekuongorora dzemukati memudziyo hadzigone kusimbiswa sedzinoshanda nemushandisi, uye izvi zvinogona kukanganisa pfungwa yekuongorora humbowo. Kana kiredhiti yekuongorora ikatorwa mukuverenga kweSIL, nzira dzekuongorora (semuenzaniso nzira dzekudzivirira dzisiri kure) dzinofanira kuongororwa sechikamu chebvunzo yekuongorora.
Nzira dzekukundikana dzinogona kukamurwa kuva idzo dzakaedzwa panguva yebvunzo, idzo dzisina kuongororwa, uye kukundikana kunotanga kana kukundikana kunoenderana nenguva. Dzimwe nzira dzekukundikana dzine njodzi dzingasaedzwa zvakananga nekuda kwezvikonzero zvakasiyana-siyana (semuenzaniso kuoma, sarudzo yeinjiniya kana yekushanda, kusaziva, kusakwanisa, kusaita kana kukanganisa kwakarongeka, mukana mudiki wekuitika, nezvimwewo). Kana paine nzira dzinozivikanwa dzekukundikana dzisingazoedzwa, muripo unofanirwa kuitwa mukugadzira mudziyo, maitiro ekuyedza, kutsiva mudziyo nguva nenguva kana kuvaka patsva, uye/kana bvunzo dzekufungidzira dzinofanira kuitwa kuderedza mhedzisiro pakusaedza kweSIF.
Kukundikana kwekutanga idambudziko kana mamiriro ezvinhu anodzikisira zvekuti kukundikana kwakakosha, kune njodzi kunogona kutarisirwa kuitika kana matanho ekugadzirisa akasatorwa nenguva. Anowanzoonekwa nekuenzanisa mashandiro ebasa nekuyedzwa kwekuongorora kwekutanga kana kwekutanga (semuenzaniso masaini evharuvhu kana nguva yekupindura kwevharuvhu) kana nekutarisa (semuenzaniso plugged process port). Kukundikana kwekutanga kunowanzoenderana nenguva—kana mudziyo kana assembly ichiri kushanda kwenguva yakareba, kunowedzera kuipa; mamiriro ezvinhu anoita kuti kukundikana kuitike zvisina tsarukano kunowedzera mukana, process port plugging kana sensor buildup nekufamba kwenguva, hupenyu hwekushandisa hunopera, nezvimwewo. Saka, kana nguva yakareba yekuedza proof, mukana wekuti kukundikana kuitike kana kunoenderana nenguva unowedzera. Chero dziviriro kubva pakukundikana kwekutanga inofanirawo kuongororwa proof (port purging, heat tracing, nezvimwewo).
Maitiro anofanirwa kunyorwa kuti aone kana paine kukundikana kune njodzi (kusingaonekwe). Maitiro ekuongorora kukundikana uye mhedzisiro (FMEA) kana maitiro ekutadza, mhedzisiro uye kuongororwa kwekuongorora (FMEDA) anogona kubatsira kuona kukundikana kune njodzi kusingaonekwe, uye uko kufukidzwa kwekuyedzwa kweuchapupu kunofanirwa kuvandudzwa.
Maitiro mazhinji ekuedza humbowo akanyorwa zvichienderana neruzivo rwakanyorwa uye matemplate kubva kumashandiro aripo. Maitiro matsva uye maSIF akaomarara anoda nzira yakagadzirwa zvakanyanya inoshandisa FMEA/FMEDA kuti iongorore kukundikana kune njodzi, kuona kuti maitiro ekuedza achaedza sei kana kuti haazoyedze sei kukundikana ikoko, uye kufukidzwa kwebvunzo. Dhayagiramu yekuongorora macro-level failure mode ye sensor inoratidzwa muMufananidzo 2. FMEA inowanzo fanirwa kuitwa kamwe chete kune rumwe rudzi rwemudziyo uye inoshandiswazve kune mimwe michina yakafanana nekufunga nezvebasa rayo rekuita, kuisa uye kugona kwayo kuyedza nzvimbo.
Kuongororwa kwekukundikana kwechikamu chikuru Mufananidzo 2: Iyi dhayagiramu yekuongorora kukundikana kwechikamu chikuru che sensor ne pressure transmitter (PT) inoratidza mabasa makuru anowanzo patsanurwa kuita akawanda micro failure analysis kuti atsanangure zvizere zvikanganiso zvinogona kugadziriswa mu functional tests.
Mufananidzo 2: Iyi dhayagiramu yekuongorora macro-level failure mode analysis block ye sensor ne pressure transmitter (PT) inoratidza mabasa makuru anowanzo patsanurwa kuita ma micro failure analysis akawanda kuti atsanangure zvizere zvikanganiso zvinogona kugadziriswa mu functional tests.
Chikamu chezvizivikanwi, zvine njodzi, uye zvisingaonekwe zvinoongororwa neuchapupu chinonzi proof test coverage (PTC). PTC inowanzo shandiswa mukuverenga kweSIL "kubhadhara" kukundikana kuyedza SIF zvizere. Vanhu vane fungidziro isiriyo yekuti nekuti vakafunga nezvekushaikwa kwebvunzo mukuverenga kwavo kweSIL, vakagadzira SIF yakavimbika. Chokwadi chiri nyore ndechekuti, kana bvunzo yako iri 75%, uye kana ukaisa nhamba iyoyo mukuverenga kwako kweSIL uye zvinhu zvaunoedza zvauri kutoedza kakawanda, 25% yekukundikana kune njodzi kunogona kuitika muhuwandu. Handidi kuva mu25%.
Mishumo yekubvumidzwa kweFMEDA nemabhuku ekuchengetedza emidziyo zvinowanzopa nzira shoma yekuedza humbowo uye kufukidzwa kwebvunzo. Izvi zvinongopa gwara chete, kwete matanho ese ekuedza anodiwa kuti pave nemaitiro akakwana ekuedza humbowo. Mamwe marudzi ekuongorora kukundikana, akadai sekuongorora kwemuti wezvikanganiso uye kugadzirisa kwakavakirwa pakuvimbika, anoshandiswawo kuongorora kukundikana kune njodzi.
Miedzo yekuratidza humbowo inogona kukamurwa kuita bvunzo dzinoshanda zvizere (kubva pakupera kusvika pakupera) kana bvunzo dzinoshanda zvishoma (Mufananidzo 3). Kuedza kwekushanda zvishoma kunowanzoitwa kana zvikamu zveSIF zvine nguva dzakasiyana dzekuedza mukuverenga kweSIL dzisingaenderane nekuvharwa kwakarongwa kana kudzoserwa. Zvakakosha kuti maitiro ekuedza humbowo hunoshanda zvishoma aenderane kuitira kuti pamwe chete vaedze mashandiro ese ekuchengetedza eSIF. Nekuyedzwa kwekushanda zvishoma, zvichiri kukurudzirwa kuti SIF ive nebvunzo yekutanga yekudzivirira kubva pakupera kusvika pakupera, uye inotevera panguva yekudzoka.
Miedzo yeuchapupu husina kukwana inofanira kusanganiswa Mufananidzo 3: Miedzo yeuchapupu husina kukwana (pazasi) inofanira kufukidza mabasa ese ebvunzo yeuchapupu husina kukwana (kumusoro).
Mufananidzo 3: Miedzo yehumbowo hwakasanganiswa (pasi) inofanira kufukidza mashandiro ese ebvunzo yehumbowo hwakazara (kumusoro).
Kuedza kwechikamu cheuchapupu kunoedza chikamu chimwe chete chenzira dzekutadza kwemudziyo. Muenzaniso unowanzoonekwa ndeye kuyedza vharuvhu isina kurohwa, apo vharuvhu inofambiswa zvishoma (10-20%) kuti ione kana isina kunamira. Izvi zvine huwandu hushoma hwebvunzo yebvunzo pane kuyedza kwechiratidzo panguva yekutanga yebvunzo.
Maitiro ekuyedza humbowo anogona kusiyana mukuomarara zvichienderana nekuomarara kweSIF uye pfungwa yemaitiro ekuyedza kambani. Mamwe makambani anonyora maitiro ekuyedza akadzama nhanho nhanho, nepo mamwe aine maitiro mapfupi. Mareferensi kune mamwe maitiro, akadai sekuyera kwakajairika, dzimwe nguva anoshandiswa kuderedza saizi yemaitiro ekuyedza humbowo uye kubatsira kuona kuti bvunzo dzinoenderana. Maitiro ekuyedza humbowo akanaka anofanira kupa ruzivo rwakakwana kuti ave nechokwadi chekuti bvunzo dzese dzakaitwa nemazvo uye dzakanyorwa, asi kwete ruzivo rwakawanda zvinoita kuti mainjiniya ade kusvetuka matanho. Kuva nenyanzvi, iyo ine basa rekuita danho rekuyedza, kutanga danho rekuyedza rakapedzwa kunogona kubatsira kuve nechokwadi chekuti bvunzo ichaitwa nemazvo. Kusaina bvunzo yehumbowo yakapedzwa neMutariri weZvishandiso nevamiriri veMabasa kuchasimbisawo kukosha uye kuvimbisa bvunzo yehumbowo yakapedzwa nemazvo.
Mhinduro dzenyanzvi dzinofanira kugara dzichikokwa kuti dzibatsire kuvandudza maitiro acho. Kubudirira kwemaitiro ekuedza humbowo kuri mumaoko enyanzvi, saka kushanda pamwe chete kunokurudzirwa zvikuru.
Kuongororwa kweuchapupu hwakawanda kunowanzoitwa pasina internet panguva yekuvharwa kana kudzoserwa kwedata. Mune zvimwe zviitiko, kuongororwa kweuchapupu kunogona kudiwa kuti kuitwe online uchimhanya kuti ugutse maverengero eSIL kana zvimwe zvinodiwa. Kuongororwa online kunoda kuronga nekushandira pamwe neOperations kuti bvunzo yeuchapupu iitwe zvakachengeteka, pasina kukanganisa maitiro, uye pasina kukonzera rwendo rwenhema. Zvinotora rwendo rumwe chete rwenhema kuti upedze zvese zvaunoita. Munguva yerudzi urwu rwebvunzo, kana SIF isiripo zvizere kuti iite basa rayo rekuchengetedza, 61511-1, Chikamu 11.8.5, chinoti "Zviyero zvekubhadhara zvinovimbisa kuti kushanda kwakachengeteka kunoramba kuripo zvichapihwa zvichienderana ne11.3 kana SIS iri mu bypass (kugadzirisa kana kuyedza)." Maitiro ekugadzirisa mamiriro asina kujairika anofanira kuenderana nemaitiro ebvunzo yeuchapupu kuti abatsire kuona kuti izvi zvaitwa nemazvo.
SIF inowanzo kamurwa kuita zvikamu zvitatu zvikuru: masensa, ma logic solvers uye zvinhu zvekupedzisira. Kunewo zvishandiso zvekubatsira zvinogona kusanganiswa mukati mechikamu chimwe nechimwe chezvikamu izvi zvitatu (semuenzaniso zvipingamupinyi zveIS, ma trip amps, ma interposing relay, ma solenoids, nezvimwewo) zvinofanirawo kuyedzwa. Zvinhu zvakakosha zvekuyedza humbowo hwese hwetekinoroji idzi zvinogona kuwanikwa mu "Testing sensors, logic solvers uye zvinhu zvekupedzisira" (pazasi).
Zvimwe zvinhu zviri nyore kuyedza pane zvimwe. Matekinoroji mazhinji emazuva ano uye mashoma ekare eflow and level ari muchikamu chakaoma zvikuru. Izvi zvinosanganisira Coriolis flowmeters, vortex metres, mag metres, through-the-air radar, ultrasonic level, uye in-situ process switches, kungotaura zvishomanana. Nerombo rakanaka, mazhinji acho ikozvino ane diagnostics dzakavandudzwa dzinobvumira bvunzo dziri nani.
Dambudziko rekuyedza humbowo hwechinhu chakadaro mumunda rinofanira kutariswa mukugadzirwa kweSIF. Zviri nyore kuti mainjiniya asarudze michina yeSIF vasina kufunga zvakanyanya nezvezvinodiwa kuti vaedze humbowo hwechinhu chacho, sezvo vasiri ivo vanochiyedza. Izvi ndezvechokwadiwo nezvekuyedza partial-stroke, inova nzira yakajairika yekuvandudza mukana weSIF wekukundikana kana uchida (PFDavg), asi gare gare makambani haadi kuzviita, uye kazhinji angasadaro. Gara uchitarisa mainjiniya eSIF maererano nekuyedza humbowo.
Kuedzwa kweuchapupu kunofanira kusanganisira kuongororwa kwekuisa nekugadzira SIF sezvinodiwa kuti zvienderane ne61511-1, Chikamu 16.3.2. Panofanira kuva nekuongorora kwekupedzisira kuona kuti zvese zvakavharwa, uye kuongorora kaviri kuti SIF yadzorerwa zvakanaka mubasa rekugadzirisa.
Kunyora nekushandisa nzira yakanaka yekuedza idanho rakakosha rekuona kuti SIF yakavimbika muhupenyu hwayo hwese. Nzira yekuedza inofanira kupa ruzivo rwakakwana kuti ive nechokwadi chekuti bvunzo dzinodiwa dzinoitwa nguva dzose uye dzakachengeteka uye dzakanyorwa. Kukundikana kune njodzi kusina kuongororwa nebvunzo dzeuchapupu kunofanirwa kubhadharwa kuitira kuti kuchengetedzeka kweSIF kuchengetwe zvakakwana muhupenyu hwayo hwese.
Kunyora nzira yakanaka yekuedza humbowo kunoda nzira ine musoro yekuongorora mainjiniya ekutadza kunogona kuitika, kusarudza nzira, uye kunyora matanho ekuedza humbowo ari mukati mehunyanzvi hwekuongorora hwefekitori. Munzira, tora mvumo yefekitori pamatanho ese ekuedza, uye dzidzisa mainjiniya kuti vaite uye vanyore bvunzo yehumbowo pamwe nekunzwisisa kukosha kwebvunzo. Nyora mirairo sekunge uri nyanzvi yemidziyo ichafanira kuita basa racho, uye kuti hupenyu hunoenderana nekuwana bvunzo nemazvo, nekuti ndizvo zvavanoita.
Testing sensors, logic solvers and final elements A SIF is typically divided up into three main parts, sensors, logic solvers and final elements. There also typically are auxiliary devices that can be associated within each of these three parts (e.g. I.S. barriers, trip amps, interposing relays, solenoids, etc.) that must also be tested.Sensor proof tests: The sensor proof test must ensure that the sensor can sense the process variable over its full range and transmit the proper signal to the SIS logic solver for evaluation. While not inclusive, some of the things to consider in creating the sensor portion of the proof test procedure are given in Table 1. Table 1: Sensor proof test considerations Process ports clean/process interface check, significant buildup noted Internal diagnostics check, run extended diagnostics if available Sensor calibration (5 point) with simulated process input to sensor, verified through to the DCS, drift check Trip point check High/High-High/Low/Low-Low alarms Redundancy, voting degradation Out of range, deviation, diagnostic alarms Bypass and alarms, restrike User diagnostics Transmitter Fail Safe configuration verified Test associated systems (e.g. purge, heat tracing, etc.) and auxiliary components Physical inspection Complete as-found and as-left documentation Logic solver proof test: When full-function proof testing is done, the logic solver’s part in accomplishing the SIF’s safety action and related actions (e.g. alarms, reset, bypasses, user diagnostics, redundancies, HMI, etc.) are tested. Partial or piecemeal function proof tests must accomplish all these tests as part of the individual overlapping proof tests. The logic solver manufacturer should have a recommended proof test procedure in the device safety manual. If not and as a minimum, the logic solver power should be cycled, and the logic solver diagnostic registers, status lights, power supply voltages, communication links and redundancy should be checked. These checks should be done prior to the full-function proof test.Don’t make the assumption that the software is good forever and the logic need not be tested after the initial proof test as undocumented, unauthorized and untested software and hardware changes and software updates can creep into systems over time and must be factored into your overall proof test philosophy. The management of change, maintenance, and revision logs should be reviewed to ensure they are up to date and properly maintained, and if capable, the application program should be compared to the latest backup.Care should also be taken to test all the user logic solver auxiliary and diagnostic functions (e.g. watchdogs, communication links, cybersecurity appliances, etc.).Final element proof test: Most final elements are valves, however, rotating equipment motor starters, variable-speed drives and other electrical components such as contactors and circuit breakers are also used as final elements and their failure modes must be analyzed and proof tested.The primary failure modes for valves are being stuck, response time too slow or too fast, and leakage, all of which are affected by the valve’s operating process interface at trip time. While testing the valve at operating conditions is the most desirable case, Operations would generally be opposed to tripping the SIF while the plant is operating. Most SIS valves are typically tested while the plant is down at zero differential pressure, which is the least demanding of operating conditions. The user should be aware of the worst-case operational differential pressure and the valve and process degradation effects, which should be factored into the valve and actuator design and sizing.Commonly, to compensate for not testing at process operating conditions, additional safety pressure/thrust/torque margin is added to the valve actuator and inferential performance testing is done utilizing baseline testing. Examples of these inferential tests are where the valve response time is timed, a smart positioner or digital valve controller is used to record a valve pressure/position curve or signature, or advance diagnostics are done during the proof test and compared with previous test results or baselines to detect valve performance degradation, indicating a potential incipient failure. Also, if tight shut off (TSO) is a requirement, simply stroking the valve will not test for leakage and a periodic valve leak test will have to be performed. ISA TR96.05.02 is intended to provide guidance on four different levels of testing of SIS valves and their typical proof test coverage, based on how the test is instrumented. People (particularly users) are encouraged to participate in the development of this technical report (contact crobinson@isa.org).Ambient temperatures can also affect valve friction loads, so that testing valves in warm weather will generally be the least demanding friction load when compared to cold weather operation. As a result, proof testing of valves at a consistent temperature should be considered to provide consistent data for inferential testing for the determination of valve performance degradation.Valves with smart positioners or a digital valve controller generally have capability to create a valve signature that can be used to monitor degradation in valve performance. A baseline valve signature can be requested as part of your purchase order or you can create one during the initial proof test to serve as a baseline. The valve signature should be done for both opening and closing of the valve. Advanced valve diagnostic should also be used if available. This can help tell you if your valve performance is deteriorating by comparing subsequent proof test valve signatures and diagnostics with your baseline. This type of test can help compensate for not testing the valve at worst case operating pressures.The valve signature during a proof test may also be able to record the response time with time stamps, removing the need for a stopwatch. Increased response time is a sign of valve deterioration and increased friction load to move the valve. While there are no standards regarding changes in valve response time, a negative pattern of changes from proof test to proof test is indicative of the potential loss of the valve’s safety margin and performance. Modern SIS valve proof testing should include a valve signature as a matter of good engineering practice.The valve instrument air supply pressure should be measured during a proof test. While the valve spring for a spring-return valve is what closes the valve, the force or torque involved is determined by how much the valve spring is compressed by the valve supply pressure (per Hooke’s Law, F = kX). If your supply pressure is low, the spring will not compress as much, hence less force will be available to move the valve when needed. While not inclusive, some of the things to consider in creating the valve portion of the proof test procedure are given in Table 2. Table 2: Final element valve assembly considerations Test valve safety action at process operating pressure (best but typically not done), and time the valve’s response time. Verify redundancy Test valve safety action at zero differential pressure and time valve’s response time. Verify redundancy Run valve signature and diagnostics as part of proof test and compare to baseline and previous test Visually observe valve action (proper action without unusual vibration or noise, etc.). Verify the valve field and position indication on the DCS Fully stroke the valve a minimum of five times during the proof test to help ensure valve reliability. (This is not intended to fix significant degradation effects or incipient failures). Review valve maintenance records to ensure any changes meet the required valve SRS specifications Test diagnostics for energize-to-trip systems Leak test if Tight Shut Off (TSO) is required Verify the command disagree alarm functionality Inspect valve assembly and internals Remove, test and rebuild as necessary Complete as-found and as-left documentation Solenoids Evaluate venting to provide required response time Evaluate solenoid performance by a digital valve controller or smart positioner Verify redundant solenoid performance (e.g. 1oo2, 2oo3) Interposing Relays Verify correct operation, redundancy Device inspection
SIF inowanzo kamurwa kuita zvikamu zvikuru zvitatu, masensa, logic solvers uye elements yekupedzisira. Kazhinji kunewo zvishandiso zvekubatsira zvinogona kubatanidzwa mune chimwe nechimwe chezvikamu izvi zvitatu (semuenzaniso, IS barriers, trip amps, interposing relay, solenoids, nezvimwewo) izvo zvinofanirawo kuyedzwa.
Kuongororwa kwekudzivirira masensa: Kuongororwa kwekudzivirira masensa kunofanirwa kuve nechokwadi chekuti sensor inogona kunzwa shanduko yemaitiro mukati mehuwandu hwayo hwese uye kutumira chiratidzo chakakodzera kune SIS logic solver kuti iongororwe. Kunyangwe zvisingasanganisire, zvimwe zvezvinhu zvekufunga nezvazvo pakugadzira chikamu che sensor chemaitiro ekuedzwa kweuchapupu zvinopihwa muTafura 1.
Kuedzwa kweLogic solver proof: Kana bvunzo ye full-function proof yaitwa, basa re logic solver mukuita zviito zvekuchengetedza zveSIF nezviito zvine chekuita nazvo (semuenzaniso ma alarm, reset, bypasses, user diagnostics, redundancies, HMI, nezvimwewo) zvinoedzwa. Miedzo ye function proof yechikamu kana piecemeal inofanira kuita bvunzo idzi dzese sechikamu chebvunzo dzega dzega dzinopindirana. Mugadziri we logic solver anofanira kunge aine nzira yekuedza proof inokurudzirwa mubhuku rekuchengetedza mudziyo. Kana zvisiri uye sezvishoma, simba re logic solver rinofanira kutenderedzwa, uye ma logic solver diagnostic registers, status lights, power supply voltages, communication links uye redundancy zvinofanirwa kuongororwa. Kuongorora uku kunofanirwa kuitwa bvunzo ye full-function proof isati yaitwa.
Usafunge kuti software iyi yakanaka nekusingaperi uye kuti logic yacho haifanirwe kuyedzwa mushure mekuyedzwa kwekutanga kweuchapupu sezvo shanduko dzesoftware nehardware dzisina magwaro, dzisina mvumo uye dzisina kuongororwa uye software updates dzinogona kupinda mumasystem nekufamba kwenguva uye dzinofanira kuverengerwa mupfungwa dzako dzebvunzo. Kutarisirwa kwekuchinja, kugadzirisa, uye magwaro ekudzokorora kunofanirwa kuongororwa kuti kuve nechokwadi chekuti akagadziridzwa uye akachengetedzwa zvakanaka, uye kana zvichikwanisika, chirongwa cheapplication chinofanira kuenzaniswa ne backup yazvino.
Kuchenjerera kunofanirawo kuitwa kuti kuyedzwe mabasa ese ekubatsira uye ekuongorora ekushandisa logic solver (semuenzaniso vachengeti, ma communication links, cybersecurity appliances, nezvimwewo).
Bvunzo rekupedzisira rinodzivirira zvinhu: Zvinhu zvakawanda zvekupedzisira mavharuvhu, zvisinei, mamota emuchina unotenderera, madhiraivha anoshanduka-shanduka nezvimwe zvinhu zvemagetsi zvakaita semacontactor nemacircuit breakers zvinoshandiswawo sezvinhu zvekupedzisira uye nzira dzadzo dzekukundikana dzinofanira kuongororwa uye kuongororwa humbowo.
Nzira huru dzekukundikana kwemavharuvhu dziri kuvharirwa, nguva yekupindura inononoka kana kuti inokurumidza, uye kubuda kwemvura, zvese izvi zvinokanganiswa nekushanda kwevharuvhu panguva yerwendo. Kunyange zvazvo kuyedza vharuvhu mumamiriro ekushanda kuri iko kunonyanya kudiwa, Mabasa anowanzo pesana nekugumburwa kweSIF apo fekitari iri kushanda. Mavharuvhu mazhinji eSIS anowanzo edzwa nepo fekitari iri pasi pa zero differential pressure, iyo iri iyo isinganyanyi kuoma mumamiriro ekushanda. Mushandisi anofanira kuziva nezve pressure yakaipisisa yekushanda uye mhedzisiro yevharuvhu ne process degradation, iyo inofanirwa kuverengerwa mukugadzirwa kwevharuvhu ne actuator uye saizi.
Commonly, to compensate for not testing at process operating conditions, additional safety pressure/thrust/torque margin is added to the valve actuator and inferential performance testing is done utilizing baseline testing. Examples of these inferential tests are where the valve response time is timed, a smart positioner or digital valve controller is used to record a valve pressure/position curve or signature, or advance diagnostics are done during the proof test and compared with previous test results or baselines to detect valve performance degradation, indicating a potential incipient failure. Also, if tight shut off (TSO) is a requirement, simply stroking the valve will not test for leakage and a periodic valve leak test will have to be performed. ISA TR96.05.02 is intended to provide guidance on four different levels of testing of SIS valves and their typical proof test coverage, based on how the test is instrumented. People (particularly users) are encouraged to participate in the development of this technical report (contact crobinson@isa.org).
Kupisa kwenzvimbo kunogonawo kukanganisa mutoro wekukweshana kwemavharuvhu, zvekuti mavharuvhu ekuyedza mumamiriro ekunze anodziya anowanzova mutoro wekukweshana usinganyanyi kuoma kana tichienzanisa nekushanda kwemamiriro ekunze anotonhora. Nekuda kweizvozvo, kuyedza mavharuvhu patembiricha yakaenzana kunofanirwa kufungwa kuti kupe data rakaenzana rekuyedza kwekufungidzira kuti varuvhu vaone kana paine kuora kwekushanda kwevharuvhu.
Mavharuvhu ane mapositi akangwara kana chinodzora mavharuvhu chedhijitari chinowanzo kwanisa kugadzira siginecha yevharuvhu inogona kushandiswa kuongorora kuora kwekushanda kwevharuvhu. Siginecha yevharuvhu yekutanga inogona kukumbirwa sechikamu cheodha yako yekutenga kana unogona kugadzira imwe panguva yekutanga bvunzo yekusimbisa kuti ishande seyekutanga. Siginecha yevharuvhu inofanira kuitwa pakuvhurwa nekuvhara kwevharuvhu. Kuongorora mavharuvhu epamusoro kunofanirawo kushandiswa kana kuripo. Izvi zvinogona kukubatsira kukuudza kana mashandiro evharuvhu yako ari kudzikira nekuenzanisa siginecha yevharuvhu yekuyedza proof uye diagnostics inotevera neyako baseline. Rudzi urwu rwebvunzo runogona kubatsira kutsiva kusaedza vharuvhu kana paine kumanikidzwa kwakanyanya kushanda.
Siginecha yevharuvhu panguva yekuedzwa kweuchapupu inogona zvakare kukwanisa kunyora nguva yekupindura netimu dzenguva, zvichibvisa kudiwa kwewachi yekumisa. Nguva yakawedzerwa yekupindura chiratidzo chekuora kwevharuvhu uye kuwedzera kwekukweshana kwevharuvhu kuti ifambise vharuvhu. Kunyange zvazvo pasina mitemo ine chekuita nekuchinja kwenguva yekupindura kwevharuvhu, maitiro asina kunaka ekuchinja kubva pakuongororwa kweuchapupu kuenda pakuongororwa kweuchapupu anoratidza kurasikirwa kunogona kuitika kwemari yekuchengetedza yevharuvhu uye mashandiro ayo. Kuongororwa kweSIS valve yemazuva ano kunofanirwa kusanganisira siginecha yevharuvhu senzira yakanaka yekugadzira mainjiniya.
Kumanikidzwa kwemhepo inoshandiswa nevharuvhu kunofanirwa kuyerwa panguva yekuedza proof. Kunyange zvazvo chitubu chevharuvhu chevharuvhu inodzosa chitubu chiri icho chinovhara vharuvhu, simba kana torque inosanganisirwa inoonekwa nekuti chitubu chevharuvhu chakamanikidzwa zvakadii nekumanikidzwa kwevharuvhu (sekureva kweMutemo waHooke, F = kX). Kana kumanikidzwa kwako kwesupply kwakaderera, chitubu hachizodzvinyiriri zvakanyanya, saka simba shoma richawanikwa rekufambisa vharuvhu kana zvichidikanwa. Kunyangwe zvisingasanganisire, zvimwe zvezvinhu zvekufunga nezvazvo pakugadzira chikamu chevharuvhu chemaitiro ekuedza proof zvinopihwa muTafura 2.
Nguva yekutumira: Mbudzi-13-2019