Gwajin shaida muhimmin bangare ne na kula da amincin tsarin kayan aikinmu na tsaro (SIS) da tsarin da suka shafi aminci (misali ƙararrawa masu mahimmanci, tsarin wuta da iskar gas, tsarin kulle kayan aiki, da sauransu). Gwajin shaida gwaji ne na lokaci-lokaci don gano gazawar haɗari, gwada ayyukan da suka shafi aminci (misali sake saitawa, wucewa, ƙararrawa, bincike, rufewa da hannu, da sauransu), da kuma tabbatar da cewa tsarin ya cika ƙa'idodin kamfani da na waje. Sakamakon gwajin shaida kuma ma'auni ne na ingancin shirin ingancin injiniyan SIS da amincin filin tsarin.
Tsarin gwajin shaida ya ƙunshi matakan gwaji tun daga samun izini, yin sanarwa da kuma cire tsarin daga aiki don gwaji zuwa tabbatar da cikakken gwaji, yin rikodin gwajin shaida da sakamakonsa, mayar da tsarin aiki, da kuma kimanta sakamakon gwajin na yanzu da sakamakon gwajin shaida na baya.
ANSI/ISA/IEC 61511-1, Sashe na 16, ya ƙunshi gwajin shaidar SIS. Rahoton fasaha na ISA TR84.00.03 – “Intechanical Instrumented Safety Instrumented Systems (SIS),” ya ƙunshi gwajin shaida kuma a halin yanzu ana kan gyara shi tare da ana sa ran fitar da sabon sigar nan ba da jimawa ba. Rahoton fasaha na ISA TR96.05.02 – “Gwajin Tabbatar da In-situ na Bawuloli Masu Aiki” a halin yanzu ana kan haɓaka shi.
Rahoton HSE na Burtaniya CRR 428/2002 – “Ka’idoji don gwajin shaida na tsarin kayan aikin aminci a masana'antar sinadarai” yana ba da bayanai kan gwajin shaida da abin da kamfanoni ke yi a Burtaniya.
Tsarin gwajin shaida ya dogara ne akan nazarin yanayin gazawar da aka sani da haɗari ga kowane ɓangare a cikin hanyar tafiya ta kayan aikin tsaro (SIF), aikin SIF a matsayin tsari, da kuma yadda (da kuma idan) za a gwada yanayin gazawar mai haɗari. Ya kamata ci gaban tsari ya fara a matakin ƙira na SIF tare da ƙirar tsarin, zaɓin sassan, da kuma tantance lokacin da kuma yadda za a gwada gwajin shaida. Kayan aikin SIS suna da matakai daban-daban na wahalar gwajin shaida waɗanda dole ne a yi la'akari da su a cikin ƙira, aiki da kulawa na SIF. Misali, mitocin orifice da masu watsa matsin lamba sun fi sauƙin gwadawa fiye da mitocin kwararar mass na Coriolis, mita mag ko firikwensin matakin radar ta iska. Tsarin aikace-aikace da bawul suma na iya shafar cikakken gwajin tabbatar da bawul don tabbatar da cewa gazawar haɗari da farko saboda lalacewa, toshewa ko gazawar da ta dogara da lokaci ba sa haifar da babban gazawa a cikin lokacin gwaji da aka zaɓa.
Duk da cewa galibi ana haɓaka hanyoyin gwajin shaida a lokacin aikin injiniya na SIF, ya kamata kuma a sake duba su ta hanyar Hukumar Fasaha ta SIS, Ayyuka da ƙwararrun kayan aiki waɗanda za su yi gwajin. Ya kamata kuma a yi nazarin amincin aiki (JSA). Yana da mahimmanci a sami amincewar masana'antar kan irin gwaje-gwajen da za a yi da kuma lokacin da za a yi, da kuma yuwuwar su ta zahiri da aminci. Misali, ba shi da amfani a ƙayyade gwajin bugun jini na ɗan lokaci lokacin da ƙungiyar Ayyuka ba za ta yarda ta yi ba. An kuma ba da shawarar cewa ƙwararren masani kan batun (SME) ya sake duba hanyoyin gwajin shaida. An nuna gwajin da ake buƙata don gwajin shaidar aiki mai cikakken aiki a cikin Hoto na 1.
Bukatun gwajin tabbatar da aiki cikakke Hoto na 1: Tsarin gwajin tabbatar da aiki cikakke don aikin kayan aikin aminci (SIF) da tsarin kayan aikin sa na aminci (SIS) ya kamata ya bayyana ko ya koma ga matakan da ke jere daga shirye-shiryen gwaji da hanyoyin gwaji zuwa sanarwa da takardu.
Siffa ta 1: Tsarin gwajin tabbatar da aiki mai cikakken bayani game da aikin kayan aikin aminci (SIF) da tsarin kayan aikin sa na aminci (SIS) ya kamata ya bayyana ko ya koma ga matakan da ke jere daga shirye-shiryen gwaji da hanyoyin gwaji zuwa sanarwa da takardu.
Gwajin shaida wani shiri ne na gyara wanda ya kamata ma'aikata masu ƙwarewa waɗanda aka horar a gwajin SIS, tsarin tabbatarwa, da kuma madaidaitan SIS da za su gwada su yi. Ya kamata a yi cikakken bayani game da tsarin kafin a yi gwajin tabbatarwa na farko, sannan a ba da ra'ayi ga Hukumar Fasaha ta SIS daga baya don ingantawa ko gyara.
Akwai manyan hanyoyin gazawa guda biyu (masu aminci ko masu haɗari), waɗanda aka raba su zuwa hanyoyi huɗu—masu haɗari waɗanda ba a gano su ba, waɗanda aka gano su da haɗari (ta hanyar ganewar asali), waɗanda ba a gano su da aminci ba kuma waɗanda aka gano su da aminci. Ana amfani da kalmomin gazawa masu haɗari da masu haɗari waɗanda ba a gano su ba a musayar su a cikin wannan labarin.
A gwajin tabbatar da SIF, muna da sha'awar yanayin gazawar da ba a gano ba, amma idan akwai binciken masu amfani da ke gano gazawar da ke da haɗari, ya kamata a gwada waɗannan binciken. Lura cewa ba kamar binciken masu amfani ba, binciken cikin na'urar yawanci ba za a iya tabbatar da shi a matsayin aiki ta mai amfani ba, kuma wannan na iya shafar falsafar gwajin tabbatarwa. Lokacin da aka ɗauki ƙimar ganewar asali a cikin lissafin SIL, ya kamata a gwada ƙararrawar ganewar asali (misali ƙararrawa daga waje) a matsayin wani ɓangare na gwajin tabbatarwa.
Za a iya ƙara raba hanyoyin gazawa zuwa waɗanda aka gwada a lokacin gwajin shaida, waɗanda ba a gwada su ba, da kuma gazawar farko ko gazawar da ta dogara da lokaci. Wasu hanyoyin gazawa masu haɗari ba za a iya gwada su kai tsaye ba saboda dalilai daban-daban (misali wahala, yanke shawara kan injiniyanci ko aiki, jahilci, rashin ƙwarewa, rashin sakaci ko kurakurai na tsari, ƙarancin yuwuwar faruwa, da sauransu). Idan akwai hanyoyin gazawa da aka sani waɗanda ba za a gwada su ba, ya kamata a yi diyya a cikin ƙirar na'ura, tsarin gwaji, maye gurbin na'ura lokaci-lokaci ko sake ginawa, da/ko gwajin tunani ya kamata a yi don rage tasirin rashin gwadawa ga SIF.
Lalacewar farko yanayi ne ko yanayi mai lalacewa wanda za a iya tsammanin zai faru idan ba a ɗauki matakan gyara a kan lokaci ba. Yawanci ana gano su ta hanyar kwatanta aiki da gwaje-gwajen shaidar ma'auni na baya-bayan nan ko na farko (misali sa hannun bawul ko lokutan amsawar bawul) ko ta hanyar dubawa (misali tashar aiki da aka toshe). Lalacewar farkon yawanci ya dogara ne akan lokaci - tsawon lokacin da na'urar ko haɗuwa ke aiki, haka zai lalace; yanayin da ke sauƙaƙa gazawar bazuwar ya zama mafi yuwuwa, sarrafa toshe tashar ko tara firikwensin akan lokaci, tsawon lokacin amfani ya ƙare, da sauransu. Saboda haka, tsawon lokacin gwajin gwaji, da yuwuwar gazawar farko ko wanda ya dogara da lokaci. Duk wani kariya daga gazawar farko kuma dole ne a gwada shi da shaida (tsarkake tashar, bin diddigin zafi, da sauransu).
Dole ne a rubuta hanyoyin gwaji don tabbatar da gazawar da ba a gano ba. Yanayin gazawa da nazarin tasirinsa (FMEA) ko dabarun yanayin gazawa, tasirinsa da nazarin cutar (FMEDA) na iya taimakawa wajen gano gazawar da ba a gano ba, da kuma inda dole ne a inganta ɗaukar hoton gwajin.
Yawancin hanyoyin gwajin shaida an rubuta su ne bisa gogewa da samfura daga hanyoyin da ake da su. Sabbin hanyoyin da SIFs masu rikitarwa suna buƙatar hanyar da ta fi ƙwarewa ta amfani da FMEA/FMEDA don yin nazari kan gazawar haɗari, tantance yadda tsarin gwajin zai gwada ko ba zai gwada waɗannan gazawar ba, da kuma rufe gwaje-gwajen. An nuna zane-zanen toshe na yanayin gazawar macro don firikwensin a Hoto na 2. FMEA yawanci yana buƙatar yin sau ɗaya kawai don wani nau'in na'ura kuma a sake amfani da shi don na'urori makamancin haka tare da la'akari da ayyukan aiwatar da su, shigarwa da ƙwarewar gwajin wurin.
Binciken gazawar matakin Macro Hoto na 2: Wannan zane-zanen toshewar yanayin gazawar matakin Macro don na'urar firikwensin da mai watsa matsin lamba (PT) yana nuna manyan ayyukan da yawanci za a rarraba su zuwa nazarin gazawar ƙananan micro da yawa don fayyace cikakken gazawar da za a magance a cikin gwaje-gwajen aiki.
Hoto na 2: Wannan zane na toshewar yanayin gazawar matakin macro don na'urar firikwensin da mai watsa matsin lamba (PT) yana nuna manyan ayyukan da yawanci za a rarraba su zuwa nazarin gazawar ƙananan ƙananan don bayyana cikakken gazawar da za a magance a cikin gwaje-gwajen aiki.
Kashi na gazawar da aka sani, masu haɗari, waɗanda ba a gano ba waɗanda aka gwada shaida ana kiransu ɗaukar nauyin gwajin shaida (PTC). Ana amfani da PTC a cikin lissafin SIL don "rama" gazawar gwada SIF gaba ɗaya. Mutane suna da kuskuren imani cewa saboda sun yi la'akari da rashin ɗaukar nauyin gwaji a cikin lissafin SIL ɗinsu, sun tsara ingantaccen SIF. Gaskiyar magana ita ce, idan ɗaukar nauyin gwajin ku shine 75%, kuma idan kun sanya wannan lambar a cikin lissafin SIL ɗinku kuma kun gwada abubuwa da yawa kuna gwadawa akai-akai, 25% na gazawar haɗari har yanzu suna iya faruwa a kididdiga. Tabbas ba na son kasancewa cikin wannan 25%.
Rahotannin amincewa da FMEDA da kuma littattafan aminci na na'urori galibi suna ba da mafi ƙarancin tsarin gwaji na shaida da kuma ɗaukar nauyin gwajin shaida. Waɗannan suna ba da jagora ne kawai, ba duk matakan gwaji da ake buƙata don cikakken tsarin gwajin shaida ba. Ana kuma amfani da wasu nau'ikan nazarin gazawa, kamar nazarin bishiyar lahani da kuma kula da aminci mai zurfi, don yin nazari kan gazawa masu haɗari.
Ana iya raba gwaje-gwajen shaida zuwa cikakken gwaji na aiki (ƙarshe-zuwa-ƙarshe) ko kuma gwajin aiki na ɓangare (Hoto na 3). Ana yin gwajin aiki na ɓangare ne lokacin da sassan SIF ke da tazara daban-daban na gwaji a cikin lissafin SIL waɗanda ba su yi daidai da rufewa ko juyawa da aka tsara ba. Yana da mahimmanci cewa hanyoyin gwajin aiki na ɓangare suna haɗuwa ta yadda tare za su gwada duk ayyukan aminci na SIF. Tare da gwajin aiki na ɓangare, har yanzu ana ba da shawarar cewa SIF ta sami gwajin farko na ƙarshe-zuwa-ƙarshe, da kuma na gaba yayin juyawa.
Ya kamata a ƙara gwaje-gwajen gwaji na ɓangare-ƙasa Hoto na 3: Gwaje-gwajen gwaji na ɓangare-ƙasa da aka haɗa (ƙasa) ya kamata su ƙunshi dukkan ayyukan cikakken gwajin gwaji na aiki (sama).
Siffa ta 3: Gwaje-gwajen da aka haɗa na gwaji mai nuna rashin aiki (ƙasa) ya kamata su ƙunshi dukkan ayyukan gwajin tabbatar da aiki mai cikakken aiki (sama).
Gwajin gwaji na ɗan lokaci yana gwada kashi ɗaya kawai na yanayin gazawar na'urar. Misali gama gari shine gwajin bawul ɗin bugun jini na ɗan lokaci, inda aka motsa bawul ɗin kaɗan (10-20%) don tabbatar da cewa bai makale ba. Wannan yana da ƙarancin murfin gwaji na gwaji fiye da gwajin gwaji a lokacin gwaji na farko.
Tsarin gwajin shaida na iya bambanta dangane da sarkakiyar SIF da falsafar tsarin gwajin kamfani. Wasu kamfanoni suna rubuta cikakkun hanyoyin gwaji mataki-mataki, yayin da wasu kuma suna da gajerun hanyoyin. Ana amfani da wasu hanyoyin, kamar daidaitaccen ma'auni, don rage girman tsarin gwajin shaida da kuma taimakawa wajen tabbatar da daidaito a gwaji. Kyakkyawan tsarin gwajin shaida ya kamata ya samar da isasshen bayani don tabbatar da cewa an kammala dukkan gwajin yadda ya kamata kuma an rubuta su, amma ba cikakken bayani don sa masu fasaha su so su tsallake matakai ba. Samun ƙwararren ma'aikacin, wanda ke da alhakin yin matakin gwajin, fara matakin gwajin da aka kammala zai iya taimakawa wajen tabbatar da cewa za a yi gwajin daidai. Sa hannu kan gwajin shaida da aka kammala ta hannun Mai Kula da Kayan Aiki da wakilan Ayyuka zai kuma jaddada mahimmanci kuma ya tabbatar da gwajin shaida da aka kammala yadda ya kamata.
Ya kamata a riƙa gayyatar ra'ayoyin ma'aikata don taimakawa wajen inganta tsarin. Nasarar tsarin gwajin shaida yana hannun ma'aikacin, don haka ana ba da shawarar yin aiki tare.
Yawancin gwaje-gwajen shaida yawanci ana yin su ne a waje da layi yayin rufewa ko juyawa. A wasu lokuta, ana iya buƙatar yin gwajin shaida ta yanar gizo yayin da ake gudu don biyan lissafin SIL ko wasu buƙatu. Gwajin kan layi yana buƙatar tsari da haɗin kai da Ayyuka don ba da damar yin gwajin shaida lafiya, ba tare da ɓata tsari ba, kuma ba tare da haifar da tafiya ta kuskure ba. Yana ɗaukar tafiya ta kuskure sau ɗaya kawai don amfani da duk masu kai hari. A lokacin wannan nau'in gwajin, lokacin da SIF ba ta da cikakken samuwa don yin aikin tsaro, 61511-1, Sashe na 11.8.5, ya bayyana cewa "Za a samar da matakan diyya waɗanda ke tabbatar da ci gaba da aiki lafiya daidai da 11.3 lokacin da SIS ke cikin hanyar wucewa (gyara ko gwaji)." Tsarin kula da yanayi mara kyau ya kamata ya tafi tare da tsarin gwajin shaida don taimakawa wajen tabbatar da an yi hakan yadda ya kamata.
Yawanci ana raba SIF zuwa manyan sassa uku: na'urori masu auna firikwensin, na'urorin warware dabaru da kuma abubuwan ƙarshe. Akwai kuma na'urori masu taimako waɗanda za a iya haɗa su a cikin kowanne daga cikin waɗannan sassa uku (misali shingen IS, amps na tafiya, na'urorin haɗa hanyoyin sadarwa, solenoids, da sauransu) waɗanda dole ne a gwada su. Ana iya samun muhimman fannoni na gwajin shaida kowanne daga cikin waɗannan fasahohin a cikin gefen gefe, "Na'urori masu auna firikwensin gwaji, na'urorin warware dabaru da abubuwan ƙarshe" (a ƙasa).
Wasu abubuwa sun fi sauƙi a gwada su fiye da wasu. Yawancin fasahohin zamani da na zamani da na zamani da na matakin da suka tsufa suna cikin rukunin da suka fi wahala. Waɗannan sun haɗa da na'urorin auna kwararar iska na Coriolis, mita vortex, mita mag, radar ta iska, matakin ultrasonic, da kuma maɓallan tsari a cikin wurin, don ambato kaɗan. Abin farin ciki, da yawa daga cikinsu yanzu suna da ingantattun bincike waɗanda ke ba da damar ingantaccen gwaji.
Dole ne a yi la'akari da wahalar gwajin shaida irin wannan na'urar a fagen a cikin ƙirar SIF. Yana da sauƙi ga injiniyanci ya zaɓi na'urorin SIF ba tare da la'akari da abin da ake buƙata don gwajin shaida ba, tunda ba za su zama mutanen da ke gwada su ba. Wannan kuma gaskiya ne game da gwajin bugun jini na ɓangare-ɓangare, wanda hanya ce ta gama gari don inganta matsakaicin yuwuwar gazawar SIF akan buƙata (PFDavg), amma daga baya a masana'antar Ayyuka ba sa son yin hakan, kuma sau da yawa ba za su iya ba. Koyaushe a ba da kulawa ga injiniyoyin SIF dangane da gwajin shaida.
Gwajin shaida ya kamata ya haɗa da duba shigarwa da gyara SIF kamar yadda ake buƙata don cika 61511-1, Sashe na 16.3.2. Ya kamata a yi duba na ƙarshe don tabbatar da komai an ɗaura maɓalli a sama, da kuma duba sau biyu cewa an mayar da SIF cikin aikin sarrafawa yadda ya kamata.
Rubutawa da aiwatar da kyakkyawan tsarin gwaji muhimmin mataki ne na tabbatar da ingancin SIF a tsawon rayuwarsa. Tsarin gwajin ya kamata ya samar da cikakkun bayanai don tabbatar da cewa an yi gwaje-gwajen da ake buƙata akai-akai kuma cikin aminci kuma an rubuta su. Ya kamata a biya diyya ga gazawar haɗari waɗanda ba a gwada su ta hanyar gwaje-gwajen shaida ba don tabbatar da cewa an kiyaye amincin SIF yadda ya kamata a tsawon rayuwarsa.
Rubuta kyakkyawan tsarin gwajin shaida yana buƙatar hanyar da ta dace don nazarin injiniya game da gazawar haɗari, zaɓar hanyoyin, da kuma rubuta matakan gwajin shaida waɗanda ke cikin ƙarfin gwajin masana'antar. A kan hanya, sami izinin masana'antu a kowane mataki don gwajin, kuma horar da masu fasaha don yin aiki da kuma rubuta gwajin shaida tare da fahimtar mahimmancin gwajin. Rubuta umarni kamar kai ne ƙwararren kayan aiki wanda zai yi aikin, kuma rayuwa ta dogara ne akan samun gwajin daidai, domin suna yi.
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
Yawanci ana raba SIF zuwa manyan sassa uku, na'urori masu auna firikwensin, masu warware dabaru da abubuwan ƙarshe. Akwai kuma na'urori masu taimako waɗanda za a iya haɗa su a cikin kowanne daga cikin waɗannan sassa uku (misali shingen IS, amps na tafiya, relay ɗin da ke haɗa hanyoyin sadarwa, solenoids, da sauransu) waɗanda suma dole ne a gwada su.
Gwaje-gwajen tabbatar da firikwensin: Gwajin tabbatar da firikwensin dole ne ya tabbatar da cewa firikwensin zai iya jin canjin tsarin a duk faɗin kewayonsa kuma ya aika da siginar da ta dace zuwa mai warware dabaru na SIS don kimantawa. Duk da cewa ba a haɗa shi ba, wasu abubuwan da za a yi la'akari da su wajen ƙirƙirar ɓangaren firikwensin na tsarin gwajin tabbatarwa an bayar da su a cikin Tebur 1.
Gwajin Tabbatar da Magani Mai Warware Matsalolin Hannu: Lokacin da aka yi gwajin tabbatar da aiki mai cikakken aiki, ana gwada ɓangaren mai warware matsalolin hannu wajen aiwatar da matakan aminci na SIF da ayyukan da suka shafi hakan (misali ƙararrawa, sake saitawa, wucewa, gano masu amfani, sake yin aiki, HMI, da sauransu). Gwaje-gwajen tabbatar da aiki mai ɗan lokaci ko na ɗan lokaci dole ne su yi duk waɗannan gwaje-gwajen a matsayin wani ɓangare na gwaje-gwajen tabbatar da aiki mai kama da juna. Ya kamata mai ƙera maganin hankuri ya sami shawarar gwajin tabbatarwa a cikin littafin amincin na'urar. Idan ba haka ba kuma a mafi ƙanƙanta, ya kamata a kunna wutar lantarki mai warware matsalolin hankuri, kuma a duba rajistar ganewar magani mai warware matsalolin hankuri, fitilun matsayi, ƙarfin wutar lantarki, hanyoyin sadarwa da sake yin aiki. Ya kamata a yi waɗannan gwaje-gwajen kafin gwajin tabbatar da aiki mai cikakken aiki.
Kada ka yi zaton cewa manhajar tana da kyau har abada kuma ba sai an gwada dabaru ba bayan gwajin farko na shaida domin canje-canjen software da hardware da ba a rubuta su ba, waɗanda ba a rubuta su ba, waɗanda ba a rubuta su ba, waɗanda ba a rubuta su ba, da waɗanda ba a rubuta su ba, da sabuntawar software na iya shiga cikin tsarin akan lokaci kuma dole ne a haɗa su cikin falsafar gwajin shaidar ku gaba ɗaya. Ya kamata a sake duba tsarin gudanar da canje-canje, kulawa, da rajistar gyara don tabbatar da cewa suna kan lokaci kuma an kiyaye su yadda ya kamata, kuma idan akwai dama, ya kamata a kwatanta shirin aikace-aikacen da sabon madadin.
Ya kamata a yi taka tsantsan wajen gwada duk ayyukan taimako da na gano hanyoyin magance matsalolin masu amfani (misali masu sa ido, hanyoyin sadarwa, na'urorin tsaro na yanar gizo, da sauransu).
Gwajin tabbatar da abubuwa na ƙarshe: Yawancin abubuwa na ƙarshe bawuloli ne, duk da haka, ana amfani da masu kunna injin juyawa, masu tuƙi masu saurin canzawa da sauran abubuwan lantarki kamar masu haɗa na'urori da masu katse da'ira azaman abubuwan ƙarshe kuma dole ne a bincika yanayin gazawar su kuma a gwada su.
Babban yanayin gazawar bawuloli shine mannewa, lokacin amsawa yayi jinkiri ko sauri, da kuma zubewa, duk waɗannan abubuwan suna shafar hanyar haɗin aikin bawul a lokacin tafiya. Duk da cewa gwada bawul ɗin a yanayin aiki shine mafi kyawun yanayi, ayyukan gabaɗaya ba za su yi daidai da karkatar da SIF ba yayin da injin ke aiki. Yawancin bawul ɗin SIS galibi ana gwada su yayin da injin ke ƙasa da matsin lamba sifili, wanda shine mafi ƙarancin buƙata a cikin yanayin aiki. Ya kamata mai amfani ya san mafi munin matsin lamba na aiki da tasirin lalacewar bawul da tsari, wanda ya kamata a haɗa shi cikin ƙirar bawul da mai kunna wutar lantarki da girmansa.
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).
Yanayin zafi na yanayi kuma na iya shafar nauyin gogayya na bawul, don haka gwajin bawul a yanayin dumi gabaɗaya zai zama mafi ƙarancin nauyin gogayya idan aka kwatanta da aikin yanayin sanyi. Sakamakon haka, ya kamata a yi la'akari da gwajin tabbatar da bawul a yanayin zafi mai daidaito don samar da bayanai masu daidaito don gwajin ma'auni don tantance lalacewar aikin bawul.
Bawuloli masu amfani da na'urori masu wayo ko kuma mai sarrafa bawul na dijital gabaɗaya suna da ikon ƙirƙirar sa hannun bawul wanda za a iya amfani da shi don sa ido kan lalacewar aikin bawul. Ana iya buƙatar sa hannun bawul na asali a matsayin wani ɓangare na odar siyan ku ko kuma za ku iya ƙirƙirar ɗaya yayin gwajin shaida na farko don zama tushen tushe. Ya kamata a yi sa hannun bawul don buɗewa da rufe bawul. Ya kamata kuma a yi amfani da binciken bawul na gaba idan akwai. Wannan zai iya taimaka muku gaya muku ko aikin bawul ɗinku yana tabarbarewa ta hanyar kwatanta sa hannun bawul na gwaji da ganewar asali na gaba tare da tushen ku. Wannan nau'in gwajin zai iya taimakawa wajen rama rashin gwada bawul ɗin a mafi munin matsin lamba na aiki.
Sa hannun bawul yayin gwajin shaida shi ma zai iya yin rikodin lokacin amsawa tare da tambarin lokaci, yana kawar da buƙatar agogon tsayawa. Ƙara lokacin amsawa alama ce ta lalacewar bawul da ƙaruwar nauyin gogayya don motsa bawul ɗin. Duk da cewa babu ƙa'idodi game da canje-canje a lokacin amsawar bawul, mummunan yanayin canje-canje daga gwajin shaida zuwa gwajin shaida yana nuna yuwuwar asarar gefen aminci da aikin bawul ɗin. Gwajin tabbatar da bawul na SIS na zamani ya kamata ya haɗa da sa hannun bawul a matsayin batun kyakkyawan aikin injiniya.
Ya kamata a auna matsin iska na na'urar bawul yayin gwajin gwaji. Duk da cewa maɓuɓɓugar bawul don bawul ɗin dawowar bazara shine abin da ke rufe bawul ɗin, ƙarfin ko ƙarfin da ke tattare da shi ana ƙayyade shi ta hanyar yawan maɓuɓɓugar bawul ɗin da matsin lambar bawul ɗin ya matse (bisa ga Dokar Hooke, F = kX). Idan matsin lambar da kake da shi ya yi ƙasa, maɓuɓɓugar ba za ta matse sosai ba, don haka ƙarancin ƙarfi zai kasance don motsa bawul ɗin lokacin da ake buƙata. Duk da cewa ba a haɗa shi ba, an ba da wasu abubuwan da za a yi la'akari da su wajen ƙirƙirar ɓangaren bawul na tsarin gwajin gwaji a cikin Tebur 2.
Lokacin Saƙo: Nuwamba-13-2019