Ukuvavanywa kobungqina yinxalenye ebalulekileyo yokugcinwa kwentembeko yokhuseleko lweenkqubo zethu ezinezixhobo zokhuseleko (SIS) kunye neenkqubo ezinxulumene nokhuseleko (umz. ii-alam ezibalulekileyo, iinkqubo zomlilo & negesi, iinkqubo zokudibanisa izixhobo, njl. njl.). Uvavanyo lobungqina luvavanyo lwamaxesha athile lokubona ukusilela okuyingozi, ukuvavanya ukusebenza okunxulumene nokhuseleko (umz. ukusetwa kwakhona, ukudlula, ii-alam, ukuxilongwa, ukuvalwa kwezandla, njl.njl.), kunye nokuqinisekisa ukuba inkqubo idibana nemigangatho yenkampani kunye nengaphandle. Iziphumo zovavanyo lobungqina zikwangumlinganiselo wokusebenza kwenkqubo ye-SIS yentembeko yoomatshini kunye nokuthembeka kwendawo yenkqubo.
Iinkqubo zovavanyo lobungqina zibandakanya amanyathelo ovavanyo ukusuka ekufumaneni iimvume, ukwenza izaziso kunye nokukhupha inkqubo ngaphandle kwenkonzo yovavanyo ukuya ekuqinisekiseni uvavanyo olubanzi, ukubhala uvavanyo lobungqina kunye neziphumo zayo, ukubuyisela inkqubo kwinkonzo, kunye nokuvavanya iziphumo zovavanyo lwangoku kunye nobungqina bangaphambili. iziphumo zovavanyo.
I-ANSI/ISA/IEC 61511-1, iGatya le-16, libandakanya uvavanyo lobungqina be-SIS. Ingxelo yobugcisa ye-ISA TR84.00.03 – “Integimenti yeMechanical Integrity of Safety Instrumented Systems (SIS),” ibandakanya uvavanyo lobungqina kwaye ngoku iphantsi kohlaziyo kunye nenguqulelo entsha elindeleke ukuba iphume kungekudala. Ingxelo yobuchwephesha be-ISA TR96.05.02 – “Uvavanyo loBubungqina be-In-situ yeeValuvu eziSebenzayo” okwangoku iphantsi kophuhliso.
Ingxelo ye-UK HSE ye-CRR 428 / 2002 - "Imigaqo yokuvavanya ubungqina beenkqubo ezikhuselekileyo zokhuseleko kwishishini lemichiza" inikeza ulwazi malunga novavanyo lobungqina kunye nokuba yintoni iinkampani ezenzayo e-UK.
Inkqubo yovavanyo lobungqina isekelwe kuhlalutyo lweendlela eziyingozi zokusilela ezaziwayo zecandelo ngalinye kwindlela yohambo yesixhobo sokhuseleko (SIF), ukusebenza kwe-SIF njengenkqubo, kunye nendlela (kwaye ukuba) yokuvavanya ukusilela okuyingozi. indlela. Uphuhliso lwenkqubo kufuneka luqale kwisigaba soyilo lwe-SIF kunye noyilo lwenkqubo, ukhetho lwamacandelo, kunye nokumiselwa kwexesha kunye nendlela yokuvavanya ubungqina. Izixhobo ze-SIS zinamanqanaba ahlukeneyo obunzima bokuvavanya ubungqina ekufuneka buthathelwe ingqalelo kuyilo lwe-SIF, ukusebenza kunye nokugcinwa. Umzekelo, iimitha ze-orifice kunye nezidlulisi zoxinzelelo zilula ukuvavanya kune-Coriolis mass flowmeters, i-mag metres okanye i- through-the-air radar sensors. Usetyenziso kunye noyilo lwevalvu lunokuchaphazela ukuqondakala kovavanyo lobungqina bevalvu ukuqinisekisa ukuba ukusilela okuyingozi kunye nokuqala ngenxa yokuthotywa, ukuplaga okanye ukusilela okuxhomekeke kwixesha akukhokheli ekusileleni okubalulekileyo kwixesha elikhethiweyo lovavanyo.
Ngelixa iinkqubo zovavanyo lobungqina ziphuhliswa ngokwesiqhelo ngexesha lobunjineli be-SIF, kufuneka ziqwalaselwe kwakhona lisiza se-SIS UGunyaziwe woBugcisa, uSebenzi kunye namagcisa esixhobo aya kwenza uvavanyo. Ucazululo lokhuseleko lomsebenzi (JSA) kufuneka nalo lwenziwe. Kubalulekile ukufumana isityalo ekuthengeni ukuba loluphi uvavanyo oluya kwenziwa kwaye nini, kunye nokunokwenzeka kwabo ngokomzimba kunye nokhuseleko. Umzekelo, akuncedi nto ukucacisa uvavanyo lwe-partial-stroke xa iqela leMisebenzi lingavuma ukuyenza. Kukwacetyiswa ukuba iinkqubo zovavanyo lobungqina zijongwe kwakhona yingcali yesifundo esizimeleyo (SME). Uvavanyo oluqhelekileyo olufunekayo kuvavanyo olupheleleyo lobungqina bokusebenza lubonisiwe kuMfanekiso 1.
Iimfuno zovavanyo lobungqina bokusebenza ngokupheleleyo Umfanekiso woku-1: Inkcazo yovavanyo olupheleleyo lobungqina bomsebenzi wesixhobo sokhuseleko (SIF) kunye nenkqubo yesixhobo sokhuseleko (SIS) kufuneka ichaze okanye ibhekisele kumanyathelo alandelelanayo ukusuka kumalungiselelo ovavanyo kunye neenkqubo zovavanyo ukuya kwizaziso kunye namaxwebhu. .
Umzobo 1: Inkcazo epheleleyo yovavanyo lobungqina bokusebenza kwesixhobo sokhuseleko (SIF) kunye nenkqubo yayo yokhuseleko (SIS) kufuneka ichaze okanye ibhekiselele kumanyathelo alandelelanayo ukusuka kumalungiselelo ovavanyo kunye neenkqubo zovavanyo ukuya kwizaziso kunye namaxwebhu.
Uvavanyo lobungqina linyathelo lokulondoloza elicwangcisiweyo ekufuneka lenziwe ngabasebenzi abanobuchule abaqeqeshwe kuvavanyo lwe-SIS, inkqubo yobungqina, kunye neelophu ze-SIS baya kuvavanya. Kufuneka kubekho ukuhamba-hamba kwenkqubo phambi kokwenza uvavanyo lokuqala lobungqina, kunye nengxelo kwisiza seSIS UGunyaziwe woBugcisa emva koko ukwenzela uphuculo okanye izilungiso.
Kukho iindlela ezimbini zokungaphumeleli eziphambili (ezikhuselekileyo okanye eziyingozi), eziye zahlulahlulwe kwiindlela ezine-eziyingozi ezingabonakaliyo, ezinobungozi ezifunyenweyo (ngokuxilongwa), zikhuselekile kwaye zifunyenwe zikhuselekile. Amagama angaphumeleliyo ayingozi kwaye ayingozi asetyenziswa ngokungafaniyo kweli nqaku.
Kuvavanyo lobungqina be-SIF, sinomdla ikakhulu kwiindlela zokungaphumeleli ezinobungozi ezingabonwayo, kodwa ukuba kukho uxilongo lomsebenzisi olufumanisa ukusilela okuyingozi, olu vavanyo kufuneka luvavanywe. Qaphela ukuba ngokungafaniyo noxilongo lomsebenzisi, uxilongo lwangaphakathi lwesixhobo alunakuqinisekiswa njengolusebenzayo ngumsebenzisi, kwaye oku kunokuba nefuthe kwifilosofi yovavanyo lobungqina. Xa ikhredithi yokuxilonga ithathwa kwizibalo ze-SIL, ii-alam zokuxilonga (umz. ii-alam eziphuma kuluhlu) kufuneka zivavanywe njengenxalenye yovavanyo lobungqina.
Iimowudi zokungaphumeleli zingahlulwa zibe kwezo zivavanyiweyo ngexesha lovavanyo lobungqina, ezo zingavavanywanga, kunye nokungaphumeleli kokuqala okanye ukungaphumeleli okuxhomekeke kwixesha. Ezinye iindlela ezinobungozi zokungaphumeleli zisenokungavavanywa ngokuthe ngqo ngezizathu ezahlukeneyo (umzekelo, ubunzima, ubunjineli okanye isigqibo sokusebenza, ukungazi, ukungakwazi, ukungenzi okanye ukwenza iimpazamo ezicwangcisiweyo, amathuba aphantsi okwenzeka, njl. njl.). Ukuba kukho iindlela zokungaphumeleli ezaziwayo ezingayi kuvavanywa, imbuyekezo kufuneka yenziwe kuyilo lwesixhobo, inkqubo yovavanyo, ukutshintshwa kwesixhobo ngamaxesha athile okanye ukwakhiwa kwakhona, kunye/okanye uvavanyo olungeyonyani kufuneka lwenziwe ukunciphisa isiphumo kwingqibelelo ye-SIF yokungavavanyi.
Ukungaphumeleli kokuqala yimeko ethoba isidima okanye imeko apho ukusilela okubalulekileyo, okunobungozi kunokulindeleka ngokufanelekileyo ukuba kwenzeke ukuba amanyathelo okulungisa awathathwanga ngexesha elifanelekileyo. Zibonwa ngokuthelekisa ukusebenza novavanyo lwamva nje okanye lokuqala lwebenchmark (umzekelo, iisignisha zevalvu okanye amaxesha okuphendula kwevalvu) okanye ngokuhlolwa (umzekelo, izibuko lenkqubo eplagiweyo). Ukungaphumeleli kokuqala kudla ngokuxhomekeke kwixesha-okukhona isixhobo okanye indibano ikwinkonzo, kokukhona sisonakala; iimeko eziququzelela ukungaphumeleli okungacwangciswanga kuye kwenzeke ngakumbi, inkqubo yokuplaga izibuko okanye isivamvo sokwakha emva kwexesha, ubomi obuluncedo buphelile, njl. Nakuphi na ukukhuselwa ngokuchasene nokusilela okwaqalayo kwakhona kufuneka kuvavanywe ubungqina (ukucoca izibuko, ukulandelwa kobushushu, njl. njl.).
Iinkqubo mazibhalwe kuvavanyo lobungqina bokungaphumeleli okuyingozi (okungabhaqwanga). Imodi yokungaphumeleli kunye nohlalutyo lwesiphumo (FMEA) okanye imodi yokungaphumeleli, i-effect and diagnostic analysis (FMEDA) iindlela zobuchule zinokunceda ukuchonga ukungaphumeleli okuyingozi okungabonakaliyo, kwaye apho ubungqina bokuvavanya ubungqina kufuneka buphuculwe.
Uninzi lweenkqubo zovavanyo lobungqina zibhalwe ngamava asekelwe kumava kunye neetemplates kwiinkqubo ezikhoyo. Iinkqubo ezintsha kunye nee-SIF ezintsonkothileyo zibiza indlela enobunjineli ngakumbi usebenzisa i-FMEA/FMEDA ukuhlalutya ukungaphumeleli okuyingozi, ukumisela ukuba inkqubo yovavanyo iya okanye ayiyi kuvavanya njani loo ntsilelo, kunye nokugubungela iimvavanyo. Umzobo webhloko yebhloki yokungaphumeleli kwinqanaba le-macro-level ye-sensor iboniswe kwi-Figure 2. I-FMEA ifuna ukuba yenziwe kube kanye kuphela kuhlobo oluthile lwesixhobo kwaye iphinde isetyenziswe kwizixhobo ezifanayo ngokuqwalasela inkqubo yabo yenkonzo, ukufakela kunye nezakhono zokuvavanya indawo. .
Uhlalutyo lokungaphumeleli kwinqanaba elikhulu Umfanekiso 2: Lo mzobo webhloko yohlalutyo lokungaphumeleli kwinqanaba le-macro-level ye-sensor kunye ne-pressure transmitter (PT) ibonisa imisebenzi emikhulu eya kuthi iqhekezwe ibe yi-multiple micro failures uhlalutyo ukuchaza ngokupheleleyo ukusilela okunokuthi kulungiswe. kwiimvavanyo zomsebenzi.
Umzobo 2: Lo mzobo wokuhlalutya imowudi yokungaphumeleli kwinqanaba le-macro-level ye-block diagram ye-sensor kunye ne-pressure transmitter (PT) ibonisa imisebenzi emikhulu eya ngokuqhelekileyo ihlulwe ibe yi-multiple micro failure ihlalutya ukuchaza ngokupheleleyo ukungaphumeleli okunokuthi kubhekiswe kwiimvavanyo zomsebenzi.
Ipesenti yokusilela okwaziwayo, okuyingozi, okungabhaqwanga okuvavanyiweyo kubizwa ngokuba yi-proof test coverage (PTC). I-PTC iqhele ukusetyenziswa kwizibalo ze-SIL “ukubuyekeza” ngokusilela ukuvavanya ngokupheleleyo i-SIF. Abantu banenkolelo ephosakeleyo yokuba ngenxa yokuba bethathele ingqalelo ukunqongophala kokhuseleko lovavanyo kubalo lwabo lwe-SIL, baye bayila i-SIF ethembekileyo. Inyaniso ecacileyo yeyokuba, ukuba uvavanyo lwakho luyi-75%, kwaye ukuba ulilinganise elo nani kwi-SIL yakho yokubala kunye nokuvavanya izinto osele uzivavanya rhoqo, i-25% yokusilela okuyingozi kusengenzeka ngokwezibalo. Ngokuqinisekileyo andifuni kuba kuloo 25%.
Iingxelo zokuvunywa kwe-FMEDA kunye neencwadana zokhuseleko zezixhobo zibonelela ngenkqubo yovavanyo lobungqina obuncinane kunye ne-coverage yovavanyo lobungqina. Ezi zibonelela ngesikhokelo kuphela, ayingawo onke amanyathelo ovavanyo afunekayo kwinkqubo yovavanyo olubanzi lobungqina. Ezinye iintlobo zokuhlalutya ukusilela, ezifana nohlalutyo lwefault tree kunye nokuthembeka okusembindini wolondolozo, nazo zisetyenziselwa ukuhlalutya ukusilela okuyingozi.
Iimvavanyo zobungqina zinokuhlulwa zibe zisebenza ngokupheleleyo (ekupheleni-ekupheleni) okanye uvavanyo oluyinxenye (umzobo 3). Uvavanyo oluyinxenye olusebenzayo luqhele ukwenziwa xa amacandelo e-SIF enamathuba ovavanyo ahlukeneyo kwizibalo ze-SIL ezingahambelani nokuvalwa okucwangcisiweyo okanye ujiko. Kubalulekile ukuba iinkqubo zovavanyo lobungqina obungaphelelanga bokusebenza zikhawulelana kangangokuba zikunye zivavanye konke ukusebenza kokhuseleko lwe-SIF. Ngovavanyo oluyinxenye olusebenzayo, kusenziwa isincomo sokuba i-SIF ibe novavanyo lobungqina bokuphela ukuya ekupheleni, kunye nolulandelayo ngexesha lotshintsho.
Iimvavanyo zobungqina obungaphelelanga kufuneka bongeze uMfanekiso 3: Iimvavanyo zobungqina obungaphelelanga ezidityanisiweyo (ezantsi) kufuneka zibandakanye yonke imisebenzi yovavanyo lobungqina obusebenzayo (phezulu).
Umzobo 3: Iimvavanyo zobungqina obungaphelelanga ezidityanisiweyo (ezantsi) kufuneka zibandakanye yonke imisebenzi yovavanyo lobungqina obusebenzayo (phezulu).
Uvavanyo lobungqina obuyinxenye luvavanya kuphela ipesenti yeendlela zokungaphumeleli kwesixhobo. Umzekelo oqhelekileyo luvavanyo lwevalvu ye-partial-stroke, apho ivalve ishenxiswa imali encinci (10-20%) ukuqinisekisa ukuba ayibambekanga. Oku kunokhuselo lobungqina obusezantsi kunovavanyo lobungqina kwixesha lovavanyo lokuqala.
Iinkqubo zovavanyo lobungqina zinokwahluka ngokuntsokotha kunye nobunzima be-SIF kunye nefilosofi yenkqubo yovavanyo lwenkampani. Ezinye iinkampani zibhala iinkqubo zovavanyo ezineenkcukacha zenyathelo nenyathelo, ngelixa ezinye zineenkqubo ezimfutshane. Iireferensi kwezinye iinkqubo, ezifana nokulinganisa okusemgangathweni, ngamanye amaxesha zisetyenziselwa ukunciphisa ubungakanani benkqubo yokuvavanya ubungqina kunye nokunceda ukuqinisekisa ukuhambelana kuvavanyo. Inkqubo yovavanyo lobungqina obulungileyo kufuneka inike iinkcukacha ezaneleyo zokuqinisekisa ukuba lonke uvavanyo lufezekisiwe kwaye lubhalwe ngokufanelekileyo, kodwa hayi iinkcukacha ezingako ukwenza ukuba amagcisa afune ukutsiba amanyathelo. Ukuba nochwepheshe, onoxanduva lokwenza inyathelo lovavanyo, okokuqala inyathelo lovavanyo olugqityiweyo lunokunceda ekuqinisekiseni ukuba uvavanyo luya kwenziwa ngokuchanekileyo. Ukusayinwa kovavanyo lobungqina obugqityiweyo yiSuphavayiza yeZixhobo nabameli boMsebenzi kwakhona kuya kugxininisa ukubaluleka nokuqinisekisa uvavanyo lobungqina obuzaliswe ngokufanelekileyo.
Ingxelo yengcali kufuneka ihlale imenywa ukunceda ukuphucula inkqubo. Impumelelo yenkqubo yovavanyo lobungqina ilele kwinxalenye enkulu kwizandla zobuchwephesha, ngoko ke inzame yentsebenziswano iyacetyiswa kakhulu.
Uninzi lovavanyo lobungqina luqhele ukwenziwa ngaphandle kwe-intanethi ngexesha lokuvalwa okanye ukujika. Kwezinye iimeko, uvavanyo lobungqina lunokufuneka lwenziwe kwi-intanethi ngelixa ubaleka ukwanelisa izibalo ze-SIL okanye ezinye iimfuno. Uvavanyo lwe-Intanethi lufuna ukucwangciswa kunye nolungelelwaniso kunye neMisebenzi ukuvumela uvavanyo lobungqina ukuba lwenziwe ngokukhuselekileyo, ngaphandle kokuphazamiseka kwenkqubo, kwaye ngaphandle kokubangela uhambo oluyinkohliso. Kuthatha uhambo olunye kuphela olukhohlisayo ukusebenzisa zonke ii-attaboys zakho. Ngethuba lolu hlobo lovavanyo, xa i-SIF ingafumaneki ngokupheleleyo ukwenza umsebenzi wayo wokhuseleko, i-61511-1, iGatya 11.8.5, ithi "Amanyathelo okubuyisela aqinisekisa ukuqhubeka nokusebenza okukhuselekileyo kuya kubonelelwa ngokuhambelana ne-11.3 xa i-SIS ingaphakathi ngokudlula (ukulungisa okanye ukuvavanywa).” Inkqubo yokulawula imeko engaqhelekanga kufuneka ihambe nenkqubo yovavanyo lobungqina ukunceda ukuqinisekisa ukuba oku kwenziwa ngokufanelekileyo.
I-SIF yohlulwe ngokwesiqhelo ibe ngamacandelo amathathu aphambili: abenzi boluvo, abasombululi bengqiqo kunye nezinto zokugqibela. Kukwakho nezixhobo ezincedisayo ezinokudityaniswa kwindawo nganye kula macandelo mathathu (umz. izithintelo ze-IS, ii-trip amps, ii-interposing relays, i-solenoids, njl. njl.) ekufuneka nazo zivavanywe. Imiba ebalulekileyo yovavanyo lobungqina nganye kwezi teknoloji inokufumaneka kwibar esecaleni, "Iinzwa zokuvavanya, izisombululi zengqiqo kunye nezinto zokugqibela" (ngezantsi).
Ezinye izinto zilula ukuvavanywa kobungqina kunezinye. Uninzi lwale mihla kunye neeteknoloji ezimbalwa zakudala kunye nenqanaba letekhnoloji likudidi olunzima ngakumbi. Ezi ziquka ii-flowmeters ze-Coriolis, iimitha ze-vortex, iimitha ze-mag, i-radar yomoya, inqanaba le-ultrasonic, kunye nokutshintsha kwenkqubo ye-in-situ, ukubiza ezimbalwa. Ngethamsanqa, uninzi lwezi ngoku luphucule uxilongo oluvumela uvavanyo oluphuculweyo.
Ubunzima bokuvavanya ubungqina kweso sixhobo kwintsimi kufuneka siqwalaselwe kuyilo lwe-SIF. Kulula kubunjineli ukukhetha izixhobo ze-SIF ngaphandle kokuqwalasela ngokunzulu oko kuya kufuneka kuvavanyo lokuvavanya isixhobo, kuba abayi kuba ngabantu abavavanyayo. Oku kukwayinyaniso ngovavanyo lwe-stroke oluyinxenye, oluyindlela eqhelekileyo yokuphucula umndilili we-SIF wokusilela kwimfuno (PFDavg), kodwa kamva kwiplanti Imisebenzi ayifuni ukuyenza, kwaye amaxesha amaninzi ayinakuyenza. Ngalo lonke ixesha bonelela ngolongamelo lweplanti yobunjineli bee-SIFs malunga novavanyo lobungqina.
Uvavanyo lobungqina kufuneka lubandakanye ukuhlolwa kofakelo lwe-SIF kunye nokulungiswa njengoko kuyimfuneko ukuhlangabezana ne-61511-1, iGatya 16.3.2. Kufuneka kubekho uhlolo lokugqibela lokuqinisekisa ukuba yonke into ifakwe amaqhosha, kwaye kujongwe kabini ukuba i-SIF ibuyiselwe ngokufanelekileyo kwinkonzo yenkqubo.
Ukubhala nokuphumeza inkqubo yovavanyo elungileyo linyathelo elibalulekileyo lokuqinisekisa ukuthembeka kwe-SIF kubomi bayo bonke. Inkqubo yovavanyo kufuneka inike iinkcukacha ezaneleyo zokuqinisekisa ukuba iimvavanyo ezifunekayo zenziwa ngokungaguqukiyo nangokukhuselekileyo kwaye zibhalwe. Iintsilelo eziyingozi ezingavavanywanga ngovavanyo lobungqina kufuneka zibuyekezwe ukuze kuqinisekiswe ukuba ukhuseleko lwe-SIF lugcinwe ngokufanelekileyo kubomi bayo bonke.
Ukubhala inkqubo yovavanyo lobungqina obulungileyo kufuna indlela enengqiqo kuhlalutyo lobunjineli bokungaphumeleli okunokuba yingozi, ukukhetha iindlela, nokubhala amanyathelo ovavanyo lobungqina angaphakathi kwisakhono sovavanyo lweplanti. Endleleni, fumana ukuthengwa kwezityalo kuwo onke amanqanaba ovavanyo, kwaye uqeqeshe amagcisa ukuba enze kwaye abhale uvavanyo lobungqina kunye nokuqonda ukubaluleka kovavanyo. Bhala imiyalelo ngokungathi ubuligcisa lesixhobo eliya kufuneka lenze umsebenzi, kwaye ubomi buxhomekeke ekufumaneni uvavanyo oluchanekileyo, kuba benza njalo.
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
I-SIF yohlulwe ngokwesiqhelo yangamacandelo amathathu aphambili, abenzi boluvo, abasombululi bengqiqo kunye nezinto zokugqibela. Kukwakho nezixhobo ezincedisayo ezinokudityaniswa kwindawo nganye kula macandelo mathathu (umz. izithintelo ze-IS, ii-trip amps, ii-interposing relays, i-solenoids, njl. njl.) ekufuneka nazo zivavanywe.
Iimvavanyo zobungqina be-Sensor: Uvavanyo lobungqina be-sensor kufuneka luqinisekise ukuba i-sensor inokubona inkqubo eguquguqukayo phezu koluhlu olupheleleyo kwaye idlulisele isignali efanelekileyo kwi-SIS logic solver ukuze ihlolwe. Ngelixa zingabandakanyiyo, ezinye zezinto ekufuneka ziqwalaselwe ekudaleni inxenye yoluvo lwenkqubo yovavanyo lobungqina zinikwe kwiTheyibhile yoku-1.
Uvavanyo lobungqina bokusonjululwa kwengqiqo: Xa uvavanyo lobungqina obupheleleyo lwenziwe, inxalenye yesisombululi sengqiqo ekuphumezeni isenzo sokhuseleko se-SIF kunye neentshukumo ezinxulumeneyo (umzekelo, ii-alam, ukusetha kwakhona, ukudlula, ukuxilongwa komsebenzisi, ukungafuneki, i-HMI, njl. njl.) ziyavavanywa. Iimvavanyo zobungqina obungaphelelanga okanye obuyintwana kufuneka baphumeze zonke ezi mvavanyo njengenxalenye yovavanyo lobungqina obudibanayo. Umenzi wesisombululo sengqiqo kufuneka abe nenkqubo ecetyiswayo yovavanyo lobungqina kwincwadi yokhuseleko lwesixhobo. Ukuba akunjalo kwaye ubuncinci, amandla okusombulula ingqiqo kufuneka ajikeleziswe, kwaye iirejista zokuxilonga ze-logic, izibane zesimo, umbane wombane, amakhonkco onxibelelwano kunye nokungafuneki kufuneka kuhlolwe. Ezi tshekhi kufuneka zenziwe phambi kovavanyo lobungqina obupheleleyo.
Musa ukwenza ukucinga ukuba isoftware ilungile ngonaphakade kwaye ingqiqo ayifuni ukuvavanywa emva kovavanyo lobungqina bokuqala njengoko kungabhalwanga, okungagunyaziswanga kwaye kungavavanywanga utshintsho lwesoftware kunye nohlaziyo lwesoftware lunokuthi lungene kwiinkqubo ngokuhamba kwexesha kwaye kufuneka lufakwe kwinto yakho yonke. ifilosofi yovavanyo lobungqina. Ulawulo lotshintsho, ukugcinwa, kunye nohlaziyo lwelog kufuneka ziqwalaselwe ukuqinisekisa ukuba zisexesheni kwaye zigcinwe ngokufanelekileyo, kwaye ukuba ziyakwazi, inkqubo yesicelo kufuneka ithelekiswe nogcino lwamva nje.
Kufuneka kuqwalaselwe kwakhona ukuvavanya yonke ingqiqo yomsebenzisi encedisayo kunye nemisebenzi yokuxilonga (umzekelo, ii-watchdogs, amakhonkco onxibelelwano, izixhobo ze-cybersecurity, njl.njl.).
Uvavanyo lokugqibela lobungqina bento: Uninzi lwezinto zokugqibela zizivalvu, nangona kunjalo, izixhobo ezijikelezayo zokuqalisa iimoto, iidrive ezinesantya esiguquguqukayo kunye nezinye izinto zombane ezinje ngee-contactors kunye neziqhekeza zeesekethe nazo zisetyenziswa njengezinto zokugqibela kwaye iindlela zabo zokungaphumeleli kufuneka zihlalutywe kwaye zivavanywe ubungqina.
Iindlela eziphambili zokungaphumeleli kwiivalvu zibambekile, ixesha lokuphendula licotha kakhulu okanye likhawuleza kakhulu, kunye nokuvuza, zonke ezo zichatshazelwa lujongano lwenkqubo yokusebenza yevalve ngexesha lohambo. Ngelixa ukuvavanya ivalve kwiimeko zokusebenza kuyeyona meko inqwenelekayo, Imisebenzi ingachaswa ngokubanzi ukukhubeka i-SIF ngelixa umatshini usebenza. Uninzi lweevalvu ze-SIS zivavanywa ngexa iplanti isezantsi kunoxinzelelo lolwahlulo oluyiqanda, oluyeyona nto ifunekayo kwiimeko zokusebenza. Umsebenzisi kufuneka aqonde olona xinzelelo lubi kakhulu lokusebenza ngokwahlukileyo kunye nevalve kunye nenkqubo yokuthotywa kweziphumo, ekufuneka zifakwe kwi-valve kunye noyilo lwe-actuator kunye nobukhulu.
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).
Amaqondo obushushu akwi-Ambient nawo anokuchaphazela imithwalo yokukhuhlana kweevalvu, ukwenzela ukuba iivalvu zokuvavanya kwimozulu efudumeleyo ziya kuba ngowona mthwalo uncinci wokukhuhlana xa uthelekisa nokusebenza kwemozulu ebandayo. Ngenxa yoko, ukuvavanywa kobungqina beevalve kwiqondo lokushisa elihambelanayo kufuneka kuthathelwe ingqalelo ukubonelela ngedatha ehambelanayo yovavanyo olungenangqiqo ukumisela ukuthotywa kokusebenza kwevalve.
Iivalvu ezineendawo ezikrelekrele okanye isilawuli sevalvu yedijithali ngokubanzi sinakho ukwenza isiginitsha yevalvu enokusetyenziswa ukujonga ukuthotywa kokusebenza kwevalvu. Isiginitsha yevalve esisiseko inokucelwa njengenxalenye yeodolo yakho yokuthenga okanye ungenza enye ngexesha lovavanyo lokuqala lobungqina ukuze usebenze njengesiseko. Utyikityo lwevalvu kufuneka lwenziwe kuzo zombini ukuvulwa kunye nokuvalwa kwevalve. Uxilongo lwevalvu ekwinqanaba eliphezulu kufuneka lusetyenziswe ukuba lukhona. Oku kunokukunceda ukukuxelela ukuba ukusebenza kwevalve yakho kuyehla ngokuthelekisa utyikityo lwevalvu yobungqina obulandelayo kunye noxilongo kunye nesiseko sakho. Olu hlobo lovavanyo lunokunceda ukuhlawulela ukungavavanyi ivalve kwiimeko ezimbi kakhulu zoxinzelelo lokusebenza.
Utyikityo lwevalvu ngexesha lovavanyo lobungqina lungakwazi kwakhona ukurekhoda ixesha lokuphendula kunye nezitampu zexesha, ukususa imfuno yesitophuwotshi. Ukunyuka kwexesha lokuphendula luphawu lokuhla kwevalve kunye nokwanda komthwalo wokukhuhlana ukuhambisa ivalve. Ngelixa kungekho migangatho malunga notshintsho kwixesha lokuphendula kwevalvu, ipateni engalunganga yotshintsho ukusuka kuvavanyo lobungqina ukuya kuvavanyo lobungqina lubonisa ilahleko enokubakho yomda wokhuseleko lwevalvu kunye nokusebenza. Uvavanyo lokuqinisekisa ivalvu ye-SIS yanamhlanje kufuneka lubandakanye utyikityo lwevalvu njengombandela wobunjineli obulungileyo.
Uxinzelelo lomoya wesixhobo sevalve kufuneka lulinganiswe ngexesha lovavanyo lobungqina. Ngelixa i-valve yasentwasahlobo yevalve yokubuyisela i-spring iyinto evala ivalve, amandla okanye i-torque ebandakanyekayo imiselwa ukuba ingakanani i-valve spring inxiniswe luxinzelelo lonikezelo lwevalvu (ngoMthetho weHooke, F = kX). Ukuba uxinzelelo lwakho lokubonelela luphantsi, intwasahlobo ayiyi kucinezela kakhulu, ngoko ke amandla amancinci aya kufumaneka ukuhambisa ivalve xa kufuneka. Ngelixa zingabandakanyiyo, ezinye zezinto ekufuneka ziqwalaselwe ekudaleni isivalo sevalvu yenkqubo yovavanyo lobungqina zinikwe kwiTheyibhile 2.
Ixesha lokuposa: Nov-13-2019
