Tijaabada caddayntu waa qayb muhiim ah oo ka mid ah ilaalinta badbaadada badbaadada nidaamyadayada qalabaysan ee badbaadada (SIS) iyo nidaamyada la xidhiidha badbaadada (tusaale alaarmiga muhiimka ah, nidaamka dabka & gaaska, nidaamyada isku xidhka qalabka, iwm.). Tijaabada caddayntu waa tijaabo xilliyeed si loo ogaado guul-darrooyinka khatarta ah, tijaabi shaqada la xidhiidha badbaadada (tusaale dib u dajin, meel-marin, alaarmiga, ogaanshaha, xidhitaanka gacanta, iwm.), iyo in la hubiyo in nidaamku buuxiyo heerarka shirkadda iyo dibadda. Natiijooyinka tijaabada caddayntu sidoo kale waa cabbir waxtarka barnaamijka daacadnimada farsamada SIS iyo isku halaynta goobta ee nidaamka.
Nidaamyada imtixaanku waxay daboolayaan tillaabooyinka tijaabada laga bilaabo helitaanka oggolaanshaha, samaynta ogeysiisyada iyo ka saarista nidaamka adeegga tijaabada si loo hubiyo hubinta imtixaanka dhammaystiran, diiwaangelinta tijaabada caddaynta iyo natiijooyinkeeda, dib u celinta nidaamka adeegga, iyo qiimaynta natiijooyinka imtixaanka hadda jira iyo caddayntii hore natiijooyinka imtixaanka.
ANSI/ISA/IEC 61511-1, Farqada 16, waxa ay dabooshaa tijaabada caddaynta SIS. Warbixinta farsamada ee ISA TR84.00.03 - "Mechanical Integrity of Safety Instrumented Systems (SIS)," waxay dabooshaa tijaabada caddaynta oo hadda waxaa ku socda dib u eegis iyadoo nooc cusub la filayo dhawaan. Warbixinta farsamada ee ISA TR96.05.02 - "Tijaabada caddaynta goobta dhexdeeda ee Valves Automated" hadda waa la horumarinayaa.
UK HSE warbixinta CRR 428/2002 - "Mabaadi'da caddaynta ee hababka qalabka badbaadada ee warshadaha kiimikada" waxay bixisaa macluumaadka ku saabsan baaritaanka caddaynta iyo waxa shirkaduhu ay ka sameynayaan UK.
Nidaamka tijaabada caddayntu wuxuu ku salaysan yahay falanqaynta hababka fashilka khatarta ah ee loo yaqaan mid kasta oo ka mid ah qaybaha ku jira waddada safarka ee badbaadada qalabka badbaadada (SIF), shaqeynta SIF nidaam ahaan, iyo sida (iyo haddii) si loo tijaabiyo fashilka khatarta ah hab. Horumarinta habraaca waa in lagu bilaabo wajiga naqshadeynta SIF iyadoo la raacayo naqshadeynta nidaamka, xulashada qaybaha, iyo go'aaminta goorta iyo sida loo caddeeyo imtixaanka. Qalabyada SIS waxay leeyihiin heerar kala duwan oo ah dhibaato tijaabinta caddaynta oo ay tahay in lagu tixgeliyo naqshadaynta, hawlgalka iyo dayactirka SIF. Tusaale ahaan, mitirka hawada sare iyo gudbiyaasha cadaadiska ayaa ka sahlan in la tijaabiyo marka loo eego Coriolis mass flowmeters, mitirka magdhowga ama dareemayaasha heerka raadaarka hawada. Codsiga iyo nashqadeynta waalka waxay sidoo kale saameyn kartaa dhammaystirka tijaabada caddaynta waalka si loo hubiyo in guuldarrooyinka khatarta ah iyo kuwa bilawga ah ee ay ugu wacan tahay xaalufka, ku xidhidhiyaha ama guuldarrooyinka wakhtiga ku-tiirsan ayan u horseedin guuldarro halis ah inta u dhaxaysa muddada tijaabada ee la doortay.
Iyadoo hababka tijaabada caddaynta sida caadiga ah la horumariyo inta lagu jiro marxaladda injineernimada SIF, waa inay sidoo kale dib u eegaan Maamulka Farsamada ee SIS, Hawlgallada iyo farsamayaqaannada qalabka kuwaas oo samayn doona imtixaanka. Waa in sidoo kale la sameeyaa falanqaynta badbaadada shaqada (JSA). Waa muhiim in la helo iibka warshada waxa imtixaanada la samayn doono iyo goorta, iyo suurtogalnimadooda jireed iyo badbaado. Tusaale ahaan, wax wanaag ah ma samaynayso in la qeexo tijaabada qayb-stroke marka kooxda Hawl-galyadu aanay oggolaan inay sameeyaan. Waxa kale oo lagu talinayaa in hababka tijaabada caddaynta uu dib u eego khabiir ku takhasusay mawduuca (SME). Imtixaanka caadiga ah ee looga baahan yahay tijaabada caddaynta shaqada oo buuxda ayaa lagu muujiyey sawirka 1.
Shuruudaha tijaabada caddaynta shaqada oo buuxda Jaantus 1: Tijaabada caddaynta shaqada buuxda ee shaqada badbaadada qalabaysan (SIF) iyo nidaamkeeda qalabka badbaadada (SIS) waa inay qeexaan ama tixraacaan tillaabooyinka isku xigxiga laga bilaabo diyaarinta imtixaanka iyo hababka tijaabada ilaa ogeysiisyada iyo waraaqaha .
Jaantus 1: Tijaabada caddaynta shaqada buuxda ee shaqada badbaadada qalabaysan (SIF) iyo nadaamkeeda qalabka badbaadada (SIS) waa inay higgaadiyaan ama tixraacaan tillaabooyinka isku xigxiga laga bilaabo diyaarinta imtixaanka iyo hababka tijaabada ilaa ogeysiisyada iyo waraaqaha.
Tijaabada caddayntu waa hawl qorshaysan oo dayactir ah oo ay tahay inay sameeyaan shaqaale karti u leh oo u tababaran imtixaanka SIS, nidaamka caddaynta, iyo wareegyada SIS ee ay tijaabin doonaan. Waa in la maraa nidaamka ka hor inta aan la samayn tijaabada caddaynta ee bilowga ah, iyo jawaab celin ku socota Maamulka Farsamada ee SIS ka dib hagaajinta ama hagaajinta.
Waxa jira laba hab fashilka aasaasiga ah (ammaan ama khatar ah), kuwaas oo loo qaybiyay afar hab-khatar aan la ogaan, khatar ah oo la ogaado (lagu ogaado), badbaado aan la ogaan iyo badbaado la ogaaday. Erayada guuldarada aan la ogaan ee khatarta ah iyo khatarta ah ayaa si is beddel ah loogu adeegsaday qodobkan.
Imtixaanka caddaynta ee SIF, waxaanu ugu horayn xiisaynaynaa hababka fashilka ee aan la ogaan ee khatarta ah, laakiin haddii ay jiraan baadhitaano isticmaale oo ogaanaya guuldarrooyinka khatarta ah, baadhitaanadan waa in la tijaabiyaa caddayn. Ogsoonow si ka duwan ogaanshaha isticmaale, ogaanshaha aaladda gudaha aaladda sida caadiga ah uma xaqiijin karo adeegsad ahaan, tani waxay saameyn kartaa falsafada tijaabada caddaynta. Marka credit for ogaanshaha lagu qaato xisaabinta SIL, alaarmiga ogaanshaha (tusaale alaarmiga ka baxsan) waa in la tijaabiyaa qayb ka mid ah tijaabada caddaynta.
Hababka guul darradu waxa loo sii kala qaybin karaa kuwa la tijaabiyey inta lagu jiro tijaabada caddaynta, kuwa aan la tijaabin, iyo guul-darrooyinka bilowga ah ama guul-darrooyinka wakhtiga ku-tiirsan. Hababka fashilka khatarta ah qaarkood waxaa laga yaabaa inaan si toos ah loo tijaabin sababo kala duwan awgood (tusaale dhib, injineernimo ama go'aan hawleed, jaahilnimo, karti-darro, ka tegitaan ama khaladaad habaysan oo komishanka ah, suurtogalnimada inay hoos u dhacdo, iwm.). Haddii ay jiraan qaabab guuldarro la yaqaan oo aan la tijaabin doonin, magdhowga waa in lagu sameeyaa qaabaynta aaladda, nidaamka tijaabada, beddelka aaladaha xilliyeed ama dib-u-dhiska, iyo/ama tijaabinta aan caqli-gal ahayn waa in la sameeyaa si loo yareeyo saamaynta ay ku leedahay hufnaanta SIF ee aan la tijaabin.
Fashilka bilawga ahi waa xaalad sharaf dhac ah ama xaalad sharaf dhac ah oo halis ah oo si macquul ah loo fili karo inay dhacdo haddii talaabooyinka sixitaanka aan la qaadin wakhti ku haboon. Caadi ahaan waxaa lagu ogaadaa marka la barbardhigo waxqabadka marka la barbar dhigo tijaabooyinka caddaynta ee dhawaan ama bilawga ah (tusaale saxeexyada waalka ama wakhtiyada jawaabta waalka) ama kormeer (tusaale deked habraac xidhan). Guuldarrooyinka bilawga ahi waxay inta badan ku xidhan yihiin wakhti-mar kasta oo ay sii dheeraato aaladda ama kulanka, way sii xumaanaysaa; xaaladaha fududeeya guuldarada random-ka waxay noqdaan kuwo aad u badan, habka dajinta dekeddu ama dareemaha oo kor u kaca wakhti ka dib, noloshii waxtarka lahayd way dhammaatay, iwm. Sidaa darteed, muddada dheer ee muddada tijaabada caddaynta, waxay u badan tahay in bilawga ama wakhtiga ku-tiirsanaanta. Kahortag kasta oo ka dhan ah guuldarrooyinka bilawga ah sidoo kale waa in la tijaabiyaa (deked nadiifin, kulayl raadin, iwm.).
Nidaamyada waa in loo qoraa si loo caddeeyo baaritaanka khatarta ah (la ogaan karo) guuldarrooyinka. Qaabka guul darada iyo falanqaynta saamaynta (FMEA) ama habka guuldarada, farsamooyinka saamaynta iyo falanqaynta ogaanshaha (FMEDA) ayaa kaa caawin kara in la aqoonsado guuldarrooyinka khatarta ah ee aan la ogaanin, iyo halka ay tahay in la hagaajiyo caymiska tijaabada.
Nidaamyo badan oo caddayn ah ayaa ah waayo-aragnimo ku saleysan qoraal iyo qaabab laga soo qaatay habraacyada jira. Nidaamyo cusub iyo SIFs aad u adag ayaa ku baaqaya hab farsamo oo dheeraad ah iyadoo la adeegsanayo FMEA/FMEDA si loo falanqeeyo guuldarrooyinka khatarta ah, go'aaminta sida nidaamka imtixaanku u tijaabin doono ama uusan u tijaabin doonin guuldarrooyinkaas, iyo daboolida imtixaannada. Nidaamka falanqaynta heerka-makro-fashilka jaantuska xannibaadda dareemayaasha ayaa lagu muujiyey Jaantuska 2. FMEA caadi ahaan waxay u baahan tahay oo keliya in la sameeyo hal mar nooc gaar ah oo qalab ah oo dib loogu isticmaalo aaladaha la midka ah iyada oo la tixgalinayo adeegyadooda habraaca, rakibidda iyo awoodda tijaabinta goobta. .
Falanqaynta fashilka heerka-Makro Jaantuska 2: Habkan heerka-makro-fashilka ah ee falanqaynta jaantuska xannibaadda dareeraha iyo gudbiyaha cadaadiska (PT) wuxuu muujinayaa hawlaha waaweyn ee sida caadiga ah loo kala qaybin doono falanqaynta fashilka yar yar si si buuxda loo qeexo guul-darrooyinka iman kara in wax laga qabto imtixaanada shaqada.
Jaantus 2: Qaabkan heerka-makro-fashilka ah ee falanqaynta jaantuska xannibaadda dareemayaasha iyo gudbiyaha cadaadiska (PT) wuxuu muujinayaa shaqooyinka waaweyn ee sida caadiga ah loo jebin doono falanqaynta fashilka yar yar si si buuxda loo qeexo guuldarrooyinka suurtagalka ah ee lagu xallinayo imtixaannada shaqada.
Boqolkiiba guuldarrooyinka la yaqaan, khatarta ah, ee aan la ogaan ee caddaynta la tijaabiyay waxaa loo yaqaan caymiska tijaabada caddaynta (PTC). PTC waxaa caadi ahaan loo isticmaalaa xisaabinta SIL si loogu "mago" fashilka in si buuxda loo tijaabiyo SIF. Dadku waxay si khaldan u aaminsan yihiin in sababtoo ah waxay tixgeliyeen la'aanta caymiska tijaabada ee xisaabinta SIL, ay u qaabeeyeen SIF la isku halayn karo. Xaqiiqda fudud ayaa ah, haddii caymiskaagu yahay 75%, iyo haddii aad lambarkaas ku dhejisay xisaabintaada SIL oo aad tijaabiso waxyaabaha aad mar hore tijaabisay marar badan, 25% guuldarrooyinka khatarta ah ayaa weli dhici kara xisaab ahaan. Waxaan hubaa inaanan rabin inaan ku jiro 25%.
Warbixinta oggolaanshaha FMDA iyo buug-gacmeedyada badbaadada ee aaladaha ayaa caadi ahaan bixiya nidaamka tijaabada caddaynta ugu yar iyo caymiska tijaabada caddaynta. Kuwani waxay bixiyaan hagitaan kaliya, maaha dhammaan tillaabooyinka tijaabada ee looga baahan yahay nidaamka tijaabada caddaynta oo dhammaystiran. Noocyada kale ee falanqaynta guuldarada, sida falanqaynta khaladka geedka iyo dayactirka ku salaysan isku halaynta, ayaa sidoo kale loo isticmaalaa in lagu falanqeeyo guuldarrooyinka khatarta ah.
Tijaabada caddaynta waxa loo qaybin karaa hawl buuxda (dhamaadka-ilaa-dhamaadka) ama tijaabada shaqaynaysa qayb (Jaantuska 3). Tijaabada hawleed ee qayb ka mid ah ayaa caadi ahaan la sameeyaa marka qaybaha SIF ay leeyihiin waqtiyo kala duwan oo tijaabo ah oo xisaabinta SIL ah oo aan la jaan qaadin xiritaanno qorsheysan ama wareegyo. Waa muhiim in habraacyada tijaabada caddaynta ee qayb ahaan ay is-kordhiyaan si ay wadajir u tijaabiyaan dhammaan hawlaha badbaadada ee SIF. Imtixaanka qayb ahaan shaqaynayo, waxa weli lagu talinayaa in SIF ay yeelato tijaabo caddayn-dhammaad-ilaa-dhammaad ah, iyo kuwa ku xiga inta lagu jiro wareegyada.
Tijaabada caddaynta ee qayb ahaan waa in lagu daraa Jaantuska 3: Imtixaanada caddaynta ee la isku daray (hoose) waa in ay daboolaan dhammaan hawlaha tijaabada caddaynta buuxda (sare).
Jaantuska 3: Imtixaanada caddaynta ee la isku daray (hoose) waa in ay daboolaan dhammaan hawlaha tijaabada caddaynta buuxda (sare).
Tijaabada caddaynta qayb ahaan waxa ay tijaabisaa boqolleyda hababka cilladda aaladda. Tusaalaha caadiga ah waa tijaabinta waalka qayb-stroke, halkaasoo waalka la raray qadar yar (10-20%) si loo xaqiijiyo in aanu xidhnayn. Tani waxay leedahay caymis ka hooseeya tijaabada caddaynta marka loo eego muddada u dhaxaysa imtixaanka aasaasiga ah.
Nidaamyada tijaabada caddayntu way ku kala duwanaan karaan kakanaanta marka la barbar dhigo kakanaanta SIF iyo falsafada nidaamka tijaabada shirkadda. Shirkadaha qaarkood waxay qoraan habraacyo tijaabo ah oo tifaftiran oo tifaftiran, halka kuwa kalena ay leeyihiin habab kooban oo cadaalad ah. Tixraacyada hababka kale, sida jaangooyada caadiga ah, ayaa mararka qaarkood loo adeegsadaa si loo dhimo cabbirka habka tijaabada caddaynta iyo in lagu caawiyo hubinta joogtaynta imtixaanka. Habka tijaabada caddaynta wanaagsan waa inuu bixiyaa tafaasiil ku filan si loo hubiyo in dhammaan imtixaannada si sax ah loo dhammaystiray oo la diiwaangeliyay, laakiin maaha mid aad u faahfaahsan si ay u keento farsamoyaqaannada inay rabaan inay ka boodaan tillaabooyinka. Haysashada farsamayaqaanka, oo mas'uul ka ah samaynta tallaabada tijaabada, bilawga tallaabada tijaabada ah ee la dhammeeyey waxay gacan ka geysan kartaa hubinta in imtixaanka si sax ah loo samayn doono. Saxiixitaanka tijaabada caddaynta ee la dhammaystiray ee Kormeeraha Qalabka iyo wakiillada hawlgallada ayaa sidoo kale xoogga saari doona muhiimadda waxayna xaqiijin doonaan in si habboon loo dhammaystiray imtixaanka caddaynta.
Jawaab celinta farsamada waa in had iyo jeer lagu martiqaadaa si ay u caawiso hagaajinta nidaamka. Guusha nidaamka tijaabada caddayntu waxay ku jirtaa qayb weyn oo ka mid ah gacmaha farsamoyaqaannada, markaa dadaal iskaashi ayaa si weyn loogu talinayaa.
Inta badan tijaabada caddaynta waxaa sida caadiga ah lagu sameeyaa khadka ka baxsan inta lagu jiro xidhitaanka ama soo noqoshada. Xaaladaha qaarkood, tijaabada caddaynta ayaa laga yaabaa in loo baahdo in lagu sameeyo onlayn marka la ordayo si loo qanciyo xisaabaadka SIL ama shuruudaha kale. Tijaabada onlaynka ahi waxay u baahan tahay qorshayn iyo iskudubarid hawl-fulineed si loogu ogolaado in tijaabada caddaynta loo sameeyo si badbaado leh, iyada oo aan habsocodku xanaaqsan, iyo iyada oo aan la keenin safar qarsoodi ah. Waxay qaadanaysaa hal safar oo kaliya si aad u isticmaasho dhammaan attaboyskaaga. Inta lagu jiro tijaabada noocaan ah, marka SIF aysan si buuxda u heli karin si ay u qabato hawsheeda badbaadada, 61511-1, faqradda 11.8.5, waxay sheegaysaa in "tallaabooyin magdhow ah oo hubinaya in hawlgal ammaan ah oo socda la bixiyo si waafaqsan 11.3 marka SIS ku jiro dhaaf (dayactirka ama tijaabinta)." Nidaamka maaraynta xaalada aan caadiga ahayn waa inuu raaco nidaamka tijaabada caddaynta si loo hubiyo in tan si sax ah loo sameeyo.
SIF waxay caadi ahaan u qaybsantaa saddex qaybood oo waaweyn: dareemayaal, xaliyayaal macquul ah iyo walxaha ugu dambeeya. Waxa kale oo jira aalado caawimo ah oo ku xidhmi kara mid kasta oo ka mid ah saddexdan qaybood (tusaale, caqabadaha IS, amps-yada safarka, relays-ka-dhex-galka, solenoids, iwm) kuwaas oo ay tahay in sidoo kale la tijaabiyo. Qaybaha muhiimka ah ee tijaabinta caddaynta mid kasta oo ka mid ah tignoolajiyadan ayaa laga yaabaa in laga helo dhinaca bar-side, "Tijaabada dareemayaasha, xalliyayaasha macquulka ah iyo walxaha kama dambaysta ah" (hoos).
Waxyaalaha qaarkood way fududahay in la caddeeyo marka loo eego kuwa kale. Qaar badan oo casri ah iyo kuwa yar oo duug ah iyo tignoolajiyada heerka ayaa ku jira qaybta ugu adag. Kuwaas waxaa ka mid ah Coriolis flowmeters, mitirka vortexka, mitirka mag, radar hawada dhex mara, heerka ultrasonic, iyo furaha habka goobta, si loo magacaabo dhowr. Nasiib wanaag, qaar badan oo kuwan ka mid ah hadda waxay heleen baaritaanno la xoojiyey oo oggolaaday in baaritaan la hagaajiyo.
Dhibaatada caddaynta tijaabinta qalabka noocaas ah ee gudaha waa in lagu tixgeliyaa naqshadda SIF. Way u fududahay injineernimada in ay doortaan aaladaha SIF iyada oo aan si dhab ah loo tixgalin waxa loo baahan yahay si loo caddeeyo tijaabinta aaladda, maadaama aysan noqon doonin dadka tijaabinaya. Tani waxay sidoo kale run ka tahay baaritaanka qayb-stroke, taas oo ah hab caadi ah oo lagu hagaajin karo celceliska suurtogalka ah ee SIF ee ku guuldareysiga baahida (PFDavg), laakiin mar dambe geedka Hawlgallada ma rabaan inay sameeyaan, marar badanna ma dhici karto. Had iyo jeer bixi kormeerka dhirta ee injineernimada SIFs ee ku saabsan tijaabada caddaynta.
Imtixaanka caddaynta waa inuu ku jiraa kormeerida rakibidda iyo dayactirka SIF haddii loo baahdo si loo buuxiyo 61511-1, Farqada 16.3.2. Waa inuu jiraa kormeer kama dambays ah si loo hubiyo in wax walba kor loo sii qaaday, iyo laba jeer oo hubin ah in SIF si sax ah dib loogu celiyay adeegga nidaamka.
Qoritaanka iyo hirgelinta nidaamka tijaabada wanaagsan waa tallaabo muhiim ah si loo hubiyo daacadnimada SIF inta ay nooshahay. Habka imtixaanku waa inuu bixiyaa tafaasiil ku filan si loo hubiyo in imtixaanada loo baahan yahay si joogto ah oo badbaado leh loo sameeyay loona diiwaangeliyay. Guuldarrooyinka khatarta ah ee aan lagu tijaabin tijaabooyinka caddaynta waa in magdhow lagu bixiyaa si loo hubiyo in badbaadada SIF ay si ku filan u ilaaliso inta uu nool yahay.
Qorista habka tijaabada caddaynta wanaagsan waxay u baahan tahay hab macquul ah oo loo eego falanqaynta injineernimada ee fashilka khatarta ah ee iman kara, xulashada hababka, iyo qorista tillaabooyinka tijaabada caddaynta ee ku jira awoodda tijaabada ee warshadda. Inta lagu jiro jidka, hel iibsashada dhirta heer kasta oo imtixaanka ah, oo u tababar farsamayaqaannada si ay u sameeyaan oo ay u diiwaangeliyaan imtixaanka caddaynta iyo sidoo kale fahmaan muhiimada imtixaanka. Qor tilmaamaha sida haddii aad tahay farsamayaqaanka qalabka kaas oo ay tahay inuu qabto shaqada, iyo in noloshu ay ku xiran tahay in la saxo baaritaanka, sababtoo ah way sameeyaan.
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 waxay caadi ahaan u qaybsantaa saddex qaybood oo waaweyn, dareemayaasha, xalliyayaasha macquulka ah iyo walxaha ugu dambeeya. Waxa kale oo jira qalab caawiye ah oo ku xidhmi kara mid kasta oo ka mid ah saddexdan qaybood (tusaale, is-hortaagyada IS, amps-yada safarka, relays-is-dhaafsiga, solenoids, iwm) kuwaas oo ay tahay in sidoo kale la tijaabiyo.
Tijaabada caddaynta dareemayaasha: Tijaabada caddaynta dareemaha waa in ay hubisaa in dareemaha uu dareemi karo doorsoomiyaha geeddi-socodkiisa oo dhan oo u gudbiya calaamadda saxda ah xaliyaha macquulka ah ee SIS si loo qiimeeyo. Iyadoo aan loo wada dhanayn, qaar ka mid ah waxyaabaha ay tahay in la tixgeliyo marka la abuurayo qaybta dareenka ee nidaamka tijaabada caddaynta ayaa lagu bixiyay Shaxda 1.
Tijaabada caddaynta xallinta macquulka ah: Marka tijaabada caddaynta shaqaynaysa ee buuxda la sameeyo, qayb xaliye caqligu ku leeyahay dhammaystirka tallaabada badbaadada ee SIF iyo ficillada la xidhiidha (tusaale alaarmiga, dib-u-dejinta, dhaafitaanka, ogaanshaha isticmaale, dib-u-celinta, HMI, iwm.) ayaa la tijaabiyaa. Tijaabooyinka caddaynta shaqada qayb ahaan ama jajabku waa inay dhammaystiraan dhammaan imtixaannadan iyada oo qayb ka ah imtixaannada caddaynta ee is-dul-saaran. Soo saaraha xallinta macquulka ah waa inuu lahaadaa habka tijaabada caddaynta ee lagu taliyey ee ku jira buug-gacmeedka badbaadada qalabka. Haddaysan ahayn iyo sida ugu yar, awoodda xalliyayaasha macquulka ah waa in baaskiil lagu wadaa, waana in la hubiyaa khabiirka xallinta ogaanshaha ogaanshaha, nalalka heerka, tamarta korontada, isku xirka isgaarsiinta iyo dib u soo celinta. Jeegagahan waa in la sameeyaa ka hor inta aan la gaadhin tijaabada caddaynta shaqaynaysa.
Ha ka fikirin in software-ku waligiis wanaagsan yahay oo caqligu uma baahna in la tijaabiyo ka dib tijaabada caddaynta bilowga ah sida kuwa aan sharciyeysnayn, aan la oggolayn oo aan la tijaabin software iyo isbeddelada qalabka iyo cusboonaysiinta softiweerku waxay geli karaan nidaamyada waqti ka dib waana in lagu saleeyaa guud ahaan kaaga. falsafada tijaabada caddaynta. Maamulka isbeddelka, dayactirka, iyo dib u eegista diiwaannada waa in dib loo eego si loo hubiyo inay casriyeysan yihiin oo si sax ah loo ilaaliyo, iyo haddii la awoodo, barnaamijka codsiga waa in la barbar dhigo kaydkii ugu dambeeyay.
Sidoo kale waa in taxaddar la sameeyaa si loo tijaabiyo dhammaan adeegsadaha caqli-galiyaha ah ee caawiya iyo hawlaha ogaanshaha (tusaale ilaaliyaasha, isku xirka isgaarsiinta, aaladaha amniga internetka, iwm.).
Tijaabada caddaynta curiyaha kama dambaysta ah: Inta badan walxaha kama dambaysta ah waa valves, si kastaba ha ahaatee, qalabka wareega ee matoorada, darawalada xawaaraha doorsooma iyo qaybaha kale ee korantada sida contactors iyo breakers sidoo kale waxaa loo isticmaalaa sida walxaha kama dambaysta ah iyo hababkooda fashilka waa in la falanqeeyaa oo caddaynta la tijaabiyaa.
Hababka fashilka aasaasiga ah ee valves waa ay xayiran yihiin, wakhtiga jawaabta aad u gaabis ah ama aad u degdeg badan, iyo daadad, kuwaas oo dhamaantood ay saameeyaan nidaamka hawlgalka waalka wakhtiga safarka. Iyadoo tijaabinta waalka ee xaaladaha shaqadu ay tahay kiiska ugu habboon, Hawlgallada guud ahaan waxay ka soo horjeedaan in la jabiyo SIF inta ay warshaddu shaqaynayso. Inta badan valves SIS waxaa sida caadiga ah la tijaabiyaa halka warshadda ay hoos ugu dhacayso eber cadaadis kala duwan, taas oo ah baahida ugu yar ee xaaladaha hawlgalka. Isticmaaluhu waa inuu ka warqabaa cadaadiska kala duwanaanshaha hawlgalka ee kiis kii ugu xumaa iyo saamaynta hoos u dhaca ee valve iyo habka, kaas oo ah in lagu saleeyo naqshadaynta iyo cabbirka valve.
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).
Heerkulka jawigu wuxuu sidoo kale saameyn karaa culeysyada jeexjeexyada waalka, sidaa darteed baarista valves ee cimilada diiran waxay guud ahaan noqon doontaa culeyska ugu baahida yar marka la barbar dhigo hawlgalka cimilada qabow. Natiijadu waxay tahay, tijaabinta caddaynta valves ee heerkul joogto ah waa in la tixgeliyo si ay u bixiso xog joogto ah oo ku saabsan baaritaanka aan macquul ahayn ee go'aaminta hoos u dhaca waxqabadka valve.
Valves leh meeleeyayaal caqli badan ama kontaroolaha waalka dhijitaalka ah ayaa guud ahaan awood u leh inay abuuraan saxeexa waalka kaas oo loo isticmaali karo si loola socdo hoos u dhaca ku yimid waxqabadka waalka. Saxeexa valve line-ka ayaa la codsan karaa iyada oo qayb ka ah dalabkaaga iibka ama waxaad samayn kartaa mid inta lagu jiro tijaabada caddaynta si aad ugu adeegto aasaas ahaan. Saxeexa waalka waa in loo sameeyaa furitaanka iyo xidhitaanka baalka. Baaritaanka waalka sare waa in sidoo kale la isticmaalaa haddii la heli karo. Tani waxay ku caawin kartaa in ay kuu sheegto in waxqabadka waalkaagu uu sii xumaanayo iyada oo la barbar dhigayo saxeexyada valve ee caddaynta ee xiga iyo ogaanshaha halka aad salka ku hayso. Tijaabada noocaan ah waxay kaa caawin kartaa inaad magdhowdo inaadan ku tijaabin waalka marka uu jiro cadaadiska shaqada ee ugu xun.
Saxeexa valve inta lagu jiro tijaabada caddaynta ayaa sidoo kale laga yaabaa inay awood u yeelato inay ku duubto wakhtiga jawaab celinta waqti stamps, taasoo meesha ka saaraysa baahida saacada joogsiga. Kordhinta wakhtiga jawaab celinta waa calaamad muujinaysa xumida waalka iyo korodhka culeyska qulqulka si loo dhaqaajiyo waalka. In kasta oo aysan jirin halbeegyo la xiriira isbeddelada waqtiga jawaabta waalka, qaabka taban ee isbeddelka tijaabada caddaynta ilaa tijaabada caddaynta ayaa tilmaamaya luminta suurtagalka ah ee xadka badbaadada waalka iyo waxqabadka. Tijaabada caddaynta waalka SIS ee casriga ah waa in ay ku jirtaa saxeexa waalka iyada oo ah arrin ku saabsan waxqabadka injineernimada wanaagsan.
Qalabka waalka ee cadaadiska hawada waa in la cabbiraa inta lagu jiro tijaabada caddaynta. Halka isha waalka ee waalka-soo-celinta gu'ga uu yahay waxa xidha waalka, xoogga ama qulqulka ku lug leh waxaa lagu go'aamiyaa inta isha waalka lagu cadaadiyo cadaadiska sahayda waalka (sida uu dhigayo sharciga Hooke, F = kX). Haddii cadaadiska sahaydu hooseeyo, gu'gu wax badan ma cadaadin doono, sidaas awgeed xoog yar ayaa la heli doonaa si loo dhaqaajiyo valve marka loo baahdo. Iyadoo aan loo wada dhanayn, qaar ka mid ah waxyaabaha la rabo in la tixgeliyo marka la abuurayo qaybta waalka ee nidaamka tijaabada caddaynta ayaa lagu bixiyay Jadwalka 2.
Waqtiga boostada: Nov-13-2019
