Nnwale ihe akaebe bụ akụkụ dị mkpa nke nleba anya nchekwa nke sistemu ihe eji arụ ọrụ nchekwa anyị (SIS) yana sistemu metụtara nchekwa (dịka egwu egwu, sistemu ọkụ & gas, sistemu ejikọtara akụrụngwa, wdg). Nnwale akaebe bụ nnwale oge iji chọpụta ọdịda dị ize ndụ, nwalee ọrụ metụtara nchekwa (dịka nrụpụta, ngafe, mkpu, nyocha, nkwuchi akwụkwọ ntuziaka, wdg), wee hụ na sistemụ na-ezute ụkpụrụ ụlọ ọrụ na nke mpụga. Nsonaazụ nke nnwale akaebe bụkwa ihe nleba anya nke ọma nke mmemme iguzosi ike n'ezi ihe nke SIS yana ntụkwasị obi ubi nke sistemu.
Usoro nnwale na-ekpuchi usoro ule site n'inweta ikike, ịme ọkwa na iwepụ sistemu ahụ n'ọrụ maka nnwale iji hụ na nnwale zuru oke, na-edekọ ule akaebe na nsonaazụ ya, na-etinyeghachi sistemụ ahụ n'ọrụ, yana nyocha nsonaazụ ule ugbu a na akaebe gara aga. nsonaazụ ule.
ANSI/ISA/IEC 61511-1, Nkeji 16, kpuchiri ule akaebe SIS. Akuko nka nka ISA TR84.00.03 – “Mechanical Integrity of Safety Instrumented Systems (SIS),” na-ekpuchi ule akaebe na a na-emegharị ya ugbu a yana ụdị ọhụrụ a na-atụ anya na ọ ga-apụta n'oge adịghị anya. Akuko nka nka ISA TR96.05.02 – “Nnwale ihe nleba anya nke valvụ akpaaka” na-emepe ugbu a.
UK HSE akụkọ CRR 428/2002 - "Ụkpụrụ maka nyocha ihe akaebe nke usoro ihe eji eme ihe nchekwa na ụlọ ọrụ kemịkalụ" na-enye ozi gbasara nyocha ihe akaebe na ihe ụlọ ọrụ na-eme na UK.
Usoro nyocha ihe akaebe dabere na nyocha nke ụdị ọdịda ọdịda ama ama ama ama maka akụrụngwa ọ bụla na ọrụ nchekwa nchekwa (SIF), ọrụ SIF dị ka sistemụ, yana otu (ma ọ bụrụ) iji nwalee maka ọdịda dị ize ndụ. ọnọdụ. Mmepe usoro kwesịrị ịmalite n'usoro nhazi SIF na nhazi usoro, nhọrọ nke akụrụngwa, na mkpebi nke oge na otu esi egosipụta ule. Ngwa SIS nwere ogo dị iche iche nke ihe isi ike nnwale nke a ga-atụle na nhazi, ọrụ na mmezi SIF. Dịka ọmụmaatụ, mita orifice na ndị na-ebugharị nrụgide dị mfe ịnwale karịa Coriolis mass flowmeters, mag mita ma ọ bụ ihe mmetụta radar dị n'ikuku. Ngwa na nhazi valvụ nwekwara ike imetụta nhụjuanya nke ule valvụ ahụ iji hụ na ọdịda dị ize ndụ na nke mmalite n'ihi mmebi, nkwụnye ma ọ bụ ọdịda dabere na oge adịghị eduga na ọdịda dị egwu n'ime oge ule ahọpụtara.
Ọ bụ ezie na a na-emepụta usoro ule akaebe n'oge usoro injinịa SIF, ụlọ ọrụ SIS Technical Authority, Ọrụ na ndị na-ahụ maka akụrụngwa ga-eme ule ahụ ga-enyocha ya. Ekwesịrị ịme nyocha nchekwa ọrụ (JSA). Ọ dị mkpa ịnweta ihe ọkụkụ na-azụta ihe nlele a ga-eme na mgbe, yana ike anụ ahụ na nchekwa ha. Dịka ọmụmaatụ, ọ baghị uru ịkọwapụta nnwale strok akụkụ mgbe otu Operations agaghị ekwenye ime ya. A na-atụkwa aro ka onye ọkachamara n'ihe gbasara isiokwu (SME) nyochaa usoro ule akaebe. Nnwale a na-ahụkarị nke achọrọ maka nnwale akaebe ọrụ zuru oke ka egosiri na eserese 1.
Ihe nleba anya nyocha ọrụ zuru oke Foto 1: Nkọwapụta ihe akaebe zuru oke maka ọrụ nchekwa akụrụngwa (SIF) na sistemu akụrụngwa nchekwa ya (SIS) kwesịrị ịkọwapụta ma ọ bụ rụtụ aka na usoro n'usoro site na nkwadebe ule na usoro nnwale na ọkwa na akwụkwọ. .
Ọnụọgụ 1: Nkọwapụta ihe akaebe zuru oke maka ọrụ nchekwa nchekwa (SIF) na sistemụ akụrụngwa nchekwa ya (SIS) kwesịrị ịkọwapụta ma ọ bụ rụtụ aka na usoro n'usoro site na nkwadebe ule na usoro nnwale na ọkwa na akwụkwọ.
Nnwale akaebe bụ mmemme mmezi akwadoro nke kwesịrị ịrụ site n'aka ndị ọrụ tozuru etozu zụrụ n'ule SIS, usoro ihe akaebe na loops SIS ha ga-anwale. Ekwesịrị inwe ịgagharị na usoro a tupu ịme ule akaebe mbụ, yana nzaghachi na saịtị SIS Technical Authority emesia maka ndozi ma ọ bụ mmezi.
Enwere ụdị ọdịda abụọ bụ isi (nchekwa ma ọ bụ dị ize ndụ), nke kewara n'ime ụzọ anọ - achọpụtaghị ihe egwu dị egwu, achọpụtara ihe dị ize ndụ (site na nyocha), nchekwa achọpụtaghị yana nchekwa. A na-eji okwu ọdịda dị ize ndụ na nke dị ize ndụ eme ihe n'otu n'otu n'ime edemede a.
N'ime ule nyocha SIF, anyị na-enwe mmasị karịsịa na ụdị ọdịda a na-achọpụtaghị dị ize ndụ, mana ọ bụrụ na enwere nchọpụta onye ọrụ na-achọpụta ọdịda dị ize ndụ, a ga-anwale nchọpụta ndị a. Rịba ama na n'adịghị ka nchọpụta onye ọrụ, nchọpụta n'ime ngwaọrụ enweghị ike ịkwado dị ka onye ọrụ na-arụ ọrụ, nke a nwere ike imetụta nkà ihe ọmụma ule akaebe. Mgbe ewere kredit maka nchọpụta nchọpụta na mgbako SIL, a ga-anwale mkpuchi nyocha (dịka ọmụmaatụ mkpu na-anọghị) dịka akụkụ nke ule akaebe.
Enwere ike kewaa ụdị ọdịda n'ime ndị a nwalere n'oge ule akaebe, ndị anaghị anwale ya, na ọdịda mmalite ma ọ bụ ọdịda dabere na oge. Enwere ike ọgaghị anwale ụfọdụ ụdị ọdịda dị ize ndụ maka ebumnuche dị iche iche (dịka ihe isi ike, injinia ma ọ bụ mkpebi arụ ọrụ, amaghị ama, enweghị ike, mwepu ma ọ bụ njehie nhazi ọrụ, ohere dị ala nke ime ihe, wdg). Ọ bụrụ na enwere ụdị ọdịda amaara nke a na-agaghị anwale maka ya, a ga-akwụ ụgwọ n'ichepụta ngwaọrụ, usoro nnwale, ngbanwe ngwaọrụ oge ma ọ bụ wughachi ya, yana / ma ọ bụ nnwale enweghị atụ iji belata mmetụta na SIF ziri ezi nke ọ bụghị nnwale.
Ọdịda mmalite bụ ọnọdụ ma ọ bụ ọnọdụ na-eweda ala nke na enwere ike ịtụ anya ọdịda dị egwu ma dị egwu ga-eme ma ọ bụrụ na emeghị ihe ndozi n'oge. A na-achọpụtakarị ha site na ntụnyere arụmọrụ na nso nso a ma ọ bụ nke mbụ ule akaebe benchmark (dịka mbinye aka valvụ ma ọ bụ oge nzaghachi valvụ) ma ọ bụ site na nyocha (dịka ọdụ ụgbọ mmiri etinyere). Ọdịda mmalite na-adaberekarị n'oge-ka ngwaọrụ ma ọ bụ mgbakọ na-arụ ọrụ, ka ọ na-ewedakwu ala; ọnọdụ na ikwado a random ọdịda na-yikarịrị, usoro plugging ọdụ ụgbọ mmiri ma ọ bụ ihe mmetụta buildup n'elu oge, ndị bara uru ndụ agwụla, wdg Ya mere, ogologo oge ule etiti oge, na-yikarịrị ihe incipient ma ọ bụ oge na-adabere ọdịda. Nchedo ọ bụla megide ọdịda mmalite ga-enwerịrị ihe akaebe (ịchacha ọdụ ụgbọ mmiri, ịchụ ọkụ, wdg).
Ekwesịrị ede usoro iji gosipụta nnwale maka ọdịda dị ize ndụ (achọpụtaghị). Ụdị ọdịda na nyocha mmetụta (FMEA) ma ọ bụ ọnọdụ ọdịda, usoro mmetụta na nyocha nchọpụta (FMEDA) nwere ike inye aka chọpụta ọdịda dị ize ndụ achọpụtaghị, yana ebe a ga-emeziwanye mkpuchi nyocha.
Ọtụtụ usoro ule akaebe na-ede ahụmịhe dabere na ndebiri sitere na usoro ndị dị adị. Usoro ọhụrụ na ndị SIF dị mgbagwoju anya na-akpọ maka usoro nhazi ọzọ site na iji FMEA / FMDA iji nyochaa maka ọdịda dị ize ndụ, chọpụta otú usoro ule ga-esi ma ọ bụ na-agaghị anwale maka ọdịda ndị ahụ, na mkpuchi nke ule. A na-egosi ihe ngosi ngọngọ nke ọdịda macro maka ihe mmetụta na eserese 2. FMEA na-adịkarị mkpa ka eme ya otu ugboro maka otu ụdị ngwaọrụ ma jiri ya mee ihe maka ngwaọrụ ndị yiri ya na-atụle ọrụ usoro ha, ntinye na ike nyocha saịtị. .
Nyocha nke ọdịda macro-Level Figure 2: Nke a macro-level ọdịda mode analysis block diagram for a sensor and pressure transmitter (PT) na-egosi isi ọrụ ndị a ga-emekarị agbajikwa n'ime otutu micro ọdịda nyocha iji kọwaa n'ụzọ zuru ezu ọdịda nwere ike idozi. na ule ọrụ.
Ọgụgụ 2: Nke a macro-larịị ọdịda mode analysis ngọngọ eserese maka a sensọ na nrụgide transmitter (PT) na-egosi ndị isi ọrụ na a ga-emekarị agbajikwa n'ime otutu micro ọdịda analysis na-akọwa n'ụzọ zuru ezu odida nwere ike na-ekwu na ọrụ ule.
Pasent nke ọdịda ama ama, dị ize ndụ, nke achọpụtaghị nke a nwalere na-egosi na a na-akpọ mkpuchi ule akaebe (PTC). A na-ejikarị PTC eme ihe na mgbako SIL iji "nkwụghachi ụgwọ" maka ọdịda ịnwale SIF nke ọma. Ndị mmadụ nwere nkwenye na-ezighi ezi na n'ihi na ha atụlewo enweghị mkpuchi nyocha na ngụkọta SIL ha, ha emepụtala SIF a pụrụ ịdabere na ya. Eziokwu dị mfe bụ, ọ bụrụ na mkpuchi ule gị bụ 75%, ma ọ bụrụ na i tinye nọmba ahụ na ngụkọ SIL gị wee nwalee ihe ndị ị na-anwale ọtụtụ oge, 25% nke ọdịda dị ize ndụ ka nwere ike ime na ọnụ ọgụgụ. Ama m na achọghị m ịnọ na 25% ahụ.
Akụkọ nkwado FMDA na akwụkwọ ntuziaka nchekwa maka ngwaọrụ na-enyekarị usoro nnwale akaebe kacha nta yana mkpuchi ule akaebe. Ndị a na-enye naanị nduzi, ọ bụghị usoro ule niile achọrọ maka usoro nnwale akaebe zuru oke. A na-ejikwa ụdị nyocha ọdịda ndị ọzọ, dị ka nyocha osisi na-adịghị mma na nrụzi dabere na ntụkwasị obi, iji nyochaa maka ọdịda dị ize ndụ.
Enwere ike kewaa ule ihe akaebe ka ọ bụrụ ọrụ zuru oke (njedebe-na-ọgwụgwụ) ma ọ bụ ule arụ ọrụ akụkụ (Njirimara 3). A na-eme nnwale na-arụ ọrụ obere oge mgbe ihe ndị dị na SIF nwere oge ule dị iche iche na ngụkọ SIL nke na-adabaghị na nkwụsịtụ ma ọ bụ ntụgharị. Ọ dị mkpa na usoro nyocha ihe akaebe na-arụ ọrụ nke ọma na-agbakọta nke na ha na-anwale ọrụ nchekwa niile nke SIF. Site n'ule nleba anya na-arụ ọrụ, a ka na-atụ aro ka SIF nwee nnwale nnwale mbido ngwụcha ruo ngwụcha, yana ndị na-esote n'oge ntụgharị.
Nnwale ihe akaebe nke akụkụ kwesịrị ịgbakwụnye foto 3: Nnwale ihe akaebe nke akụkụ (ala) jikọtara ọnụ kwesịrị ikpuchi ọrụ niile nke nnwale nnwale arụmọrụ zuru oke (n'elu).
Ọnụọgụ 3: Nnwale ihe akaebe jikọtara ọnụ (ala) kwesịrị ikpuchi ọrụ niile nke ule akaebe zuru oke (n'elu).
Nnwale ihe akaebe na-anwale naanị pasentị nke ụdị ọdịda ngwaọrụ. Otu ihe atụ a na-ahụkarị bụ ule valvụ akụkụ-strok, ebe a na-ebugharị valvụ ahụ obere ego (10-20%) iji chọpụta na ọ dịghị arapara. Nke a nwere mkpuchi ule akaebe dị ala karịa ule akaebe na etiti ule izizi.
Usoro nyocha ihe akaebe nwere ike ịdịgasị iche na mgbagwoju anya na mgbagwoju anya nke SIF na nkà ihe ọmụma usoro ule ụlọ ọrụ. Companiesfọdụ ụlọ ọrụ na-ede usoro nyocha nke ọma site na nzọụkwụ, ebe ndị ọzọ nwere usoro dị nkenke. A na-eji ntụnye aka na usoro ndị ọzọ, dị ka nhazi ọkọlọtọ, mgbe ụfọdụ iji belata nha nke usoro ule akaebe na iji nyere aka hụ na ọ na-agbanwe agbanwe na nyocha. Usoro nyocha nke ọma kwesịrị inye nkọwa zuru oke iji hụ na emezuru ule niile nke ọma ma dekọọ ya, mana ọ bụghị nkọwa zuru oke iji mee ka ndị nka na-ahụ maka ọrụ chọrọ ịgafe usoro. N'inwe onye ọrụ nka, onye na-ahụ maka ịme usoro ule ahụ, ibido usoro ule emechara nwere ike inye aka hụ na a ga-eme ule ahụ nke ọma. Nbanye nke ule akaebe emechara site n'aka onye na-ahụ maka akụrụngwa na ndị nnọchi anya ọrụ ga-emesikwa mkpa ọ dị ma kwenye na nnwale akaebe emechara nke ọma.
Ekwesịrị ịkpọ nzaghachi ndị ọkachamara mgbe niile iji nyere aka melite usoro ahụ. Ọganihu nke usoro nyocha ihe akaebe na-adabere na akụkụ dị ukwuu na aka ndị ọkachamara, ya mere a na-atụ aro mgbalị imekọ ihe ọnụ.
A na-emekarị ule akaebe na-anọghị n'ahịrị n'oge mmechi ma ọ bụ ntụgharị. N'ọnọdụ ụfọdụ, enwere ike ịchọ nyocha ihe akaebe na ntanetị ka ị na-agba ọsọ iji meju ngụkọta SIL ma ọ bụ ihe ndị ọzọ achọrọ. Nnwale n'ịntanetị chọrọ atụmatụ na nhazi ya na Ọrụ iji kwe ka emee ule akaebe ahụ n'enweghị nsogbu, na-enweghị usoro iwe, na-enweghị ịkpata njem na-adịghị mma. Ọ na-ewe naanị otu njem na-adịghị mma iji jikwaa ndị na-anya gị niile. N'oge ụdị ule a, mgbe SIF na-adịghị zuru ezu iji rụọ ọrụ nchekwa ya, 61511-1, Nkeji edemede 11.8.5, na-ekwu na "A ga-enye usoro nkwụghachi ụgwọ nke na-eme ka ọrụ nchekwa na-aga n'ihu dị ka 11.3 mgbe SIS nọ na ya. uzo (mmezi ma ọ bụ ule)." Usoro nlekọta ọnọdụ na-adịghị mma kwesịrị ịga na usoro nyocha ihe akaebe iji nyere aka hụ na emechara nke a nke ọma.
A na-ekekarị SIF ụzọ atọ: sensọ, mgbagha mgbagha na ihe ikpeazụ. Enwekwara ngwaọrụ inyeaka nke enwere ike ijikọ n'ime akụkụ atọ ndị a (dịka ihe mgbochi IS, amps njem, relays interposing, solenoids, wdg) nke a ga-anwalerịrị. Enwere ike ịhụ akụkụ dị oke mkpa nke nyocha nke teknụzụ ndị a na sidebar, "Ihe mmetụta nnwale, ndị na-edozi mgbagha na ihe ikpeazụ" (n'okpuru).
Ụfọdụ ihe na-adị mfe ịnwale karịa ndị ọzọ. Ọtụtụ teknụzụ ọgbara ọhụrụ na nke ochie ole na ole na teknụzụ dị larịị nọ na ngalaba siri ike karị. Ndị a gụnyere Coriolis flowmeters, vortex mita, mag mita, site na-ikuku radar, ultrasonic larịị, na n'ime-site mgbanwe mgbanwe, ịkpọ ole na ole. Ọ dabara nke ọma, ọtụtụ n'ime ndị a enwetala nyocha nyocha nke na-enye ohere nnwale ka mma.
A ghaghị ịtụle ihe isi ike nke ihe akaebe na-anwale ngwaọrụ dị otú ahụ n'ọhịa na nhazi SIF. Ọ dị mfe maka injinia ịhọrọ ngwaọrụ SIF na-enweghị echiche siri ike nke ihe a ga-achọ iji gosipụta nnwale ngwaọrụ ahụ, ebe ọ bụ na ha agaghị abụ ndị na-anwale ha. Nke a bụkwa eziokwu maka nnwale strok nke akụkụ, nke bụ ụzọ a na-ahụkarị iji meziwanye ohere nke ọdịda SIF na-achọ (PFDavg), mana emesia na arụ ọrụ osisi achọghị ime ya, ọtụtụ oge nwere ike ọ gaghị. Na-enye nlekọta ụlọ ọrụ mgbe niile maka injinịa SIFs n'ihe gbasara nnwale akaebe.
Nnwale ihe akaebe kwesịrị ịgụnye nyocha nke nrụnye SIF na nrụzi ka ọ dị mkpa iji zute 61511-1, Nkeji edemede 16.3.2. Ekwesịrị inwe nyocha ikpeazụ iji hụ na agbachiri ihe niile, yana nlele ugboro abụọ na etinyela SIF nke ọma na ọrụ nhazi.
Ide na itinye usoro nyocha nke ọma bụ ihe dị mkpa iji hụ na iguzosi ike n'ezi ihe nke SIF n'oge ndụ ya. Usoro ule kwesịrị inye nkọwa zuru oke iji hụ na a na-eme ule ndị achọrọ mgbe niile na n'enweghị nsogbu ma dekọọ ya. Ekwesịrị ịkwụ ụgwọ ọdịda dị ize ndụ na-anwaleghị site na nyocha ihe akaebe iji hụ na edobere nchekwa nchekwa SIF nke ọma n'oge ndụ ya niile.
Ide usoro nyocha nke ọma na-achọ ụzọ ezi uche dị na ya maka nyocha injinia nke ọdịda dị ize ndụ nwere ike ịhọpụta, na-ahọpụta ụzọ, na ide usoro nnwale nnwale nke dị n'ime ikike nnwale nke osisi. N'ụzọ, nweta ịzụrụ ihe ọkụkụ n'ọkwa niile maka ule ahụ, ma zụọ ndị ọrụ nka ka ha rụọ ma detuo ule akaebe yana ghọta mkpa ule ahụ dị. Dee ntụziaka dị ka a ga-asị na ị bụ onye na-ahụ maka ngwá ọrụ nke ga-arụ ọrụ ahụ, na ndụ na-adabere n'inweta ule nke ọma, n'ihi na ha na-eme ya.
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
A na-ekewa SIF ka ọ bụrụ akụkụ atọ, ihe mmetụta, ihe mgbagha na ihe ikpeazụ. A na-enwekwa ngwaọrụ inyeaka enwere ike ijikọ n'ime akụkụ atọ ndị a (dịka ihe mgbochi IS, amps njem, relays interposing, solenoids, wdg) nke a ga-anwalerịrị.
Nnwale ihe akaebe sensọ: Nnwale ihe ngosi sensọ ga-ahụrịrị na ihe mmetụta ahụ nwere ike ịhụ mgbanwe usoro n'ofe ya zuru oke wee bufee mgbama kwesịrị ekwesị na mgbagha mgbagha SIS maka nleba anya. Ọ bụ ezie na ọ bụghị gụnyere, ụfọdụ n'ime ihe ndị a ga-atụle n'ịmepụta akụkụ mmetụta nke usoro ule akaebe ka e nyere na Tebụl 1.
Nnwale mgbagha mgbagha: Mgbe emechara nnwale akaebe zuru oke, a na-anwale akụkụ nke mgbagha n'imezu ihe nchekwa SIF na omume ndị metụtara ya (dịka mkpu, nrụpụta, ngafe, nchọpụta onye ọrụ, redundancies, HMI, wdg). Nnwale akaebe ọrụ akụkụ ma ọ bụ iberibe ga-emecharịrị ule ndị a niile dịka akụkụ nke nnwale akaebe n'otu n'otu. Onye na-emepụta ihe mgbagha kwesịrị inwe usoro nnwale akwadoro na ntuziaka nchekwa ngwaọrụ. Ọ bụrụ na ọ bụghị na dị ka opekempe, a ga-agbagharị ike mgbagha mgbagha, na ndekọ ndekọ nyocha nke mgbagha, ọkụ ọnọdụ, voltaji ọkụ ọkụ, njikọ nkwurịta okwu na redundancy kwesịrị ịlele. Ekwesịrị ime nlele ndị a tupu ule akaebe zuru oke.
Emela ka a na-eche na software dị mma ruo mgbe ebighị ebi na ezi uche adịghị anwale mgbe mbụ anwale ule dị ka enweghị akwụkwọ, enweghị ikike na-anwale software na ngwaike mgbanwe na software mmelite nwere ike na-abanye n'ime usoro n'ime oge na a ga- factored n'ime gị mkpokọta. proof test philosophy. A ga-enyocha njikwa mgbanwe, nrụzi, na ndekọ nlegharị anya iji hụ na ha dị ọhụrụ ma na-echekwa nke ọma, ma ọ bụrụ na enwere ike, a ga-atụnyere mmemme ngwa ahụ na nkwado ndabere ọhụrụ.
Ekwesịrị ịkpachapụ anya iji nwalee onye ọrụ mgbagha mgbagha ihe enyemaka na ọrụ nyocha (dịka ndị nche, njikọ nzikọrịta ozi, ngwa cybersecurity, wdg).
Nnwale ihe akaebe ikpeazụ: Ọtụtụ ihe ikpeazụ bụ valves, Otú ọ dị, ndị na-agbagharị ngwa ngwa moto, draịva na-agba ọsọ na ngwa eletrik ndị ọzọ dị ka kọntaktị na ndị na-agbaji sekit ka a na-ejikwa dị ka ihe ikpeazụ na ụdị ọdịda ha ga-enyocha ma nwalee ihe akaebe.
Ụdị ọdịda bụ isi maka valvụ na-arapara n'ahụ, oge nzaghachi ngwa ngwa ma ọ bụ dị oke ngwa ngwa, na ntapu, ihe niile nke usoro ọrụ valve na-emetụta n'oge njem. Mgbe ị na-anwale valvụ na ọnọdụ arụ ọrụ bụ ikpe kachasị mma, ọrụ ga-emegidekarị imebi SIF mgbe osisi ahụ na-arụ ọrụ. A na-anwale ọtụtụ valvụ SIS mgbe osisi ahụ na-agbada na nrụgide dị iche iche efu, nke bụ nke kachasị achọ ọnọdụ ọrụ. Onye ọrụ kwesịrị ịma banyere nrụgide dị iche iche arụ ọrụ kachasị njọ na valvụ na mmetụta mmebi nke usoro, nke a ga-etinye n'ime valvụ na nhazi nhazi na nha.
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).
Okpomọkụ ihu igwe nwekwara ike imetụta ibu esemokwu valvụ, nke mere na valvụ nnwale na ihu igwe na-ekpo ọkụ ga-abụkarị ibu esemokwu kachasị na-achọkarị ma e jiri ya tụnyere ọrụ ihu igwe oyi. N'ihi ya, a ga-atụle ule nyocha nke valves na okpomọkụ na-agbanwe agbanwe iji nye data na-agbanwe agbanwe maka nyocha nke enweghị atụ maka ikpebi mmebi arụmọrụ valve.
Valves nwere smart positioners ma ọ bụ onye na-ahụ maka valvụ dijitalụ n'ozuzu nwere ikike imepụta akara valvụ enwere ike iji nyochaa mmebi na arụmọrụ valvụ. Enwere ike ịrịọ mbinye aka valvụ ntọala dị ka akụkụ nke usoro ịzụrụ ihe ma ọ bụ ị nwere ike ịmepụta otu n'oge ule akaebe mbụ iji rụọ ọrụ dị ka ntọala. Ekwesịrị ime akara valvụ maka oghere na mmechi nke valvụ ahụ. Ekwesịrị iji nyocha valvụ dị elu mee ihe ma ọ bụrụ na ọ dị. Nke a nwere ike inyere gị aka ịgwa gị ma ọ bụrụ na arụrụ ọrụ valvụ gị na-akawanye njọ site n'iji akara mbinye aka valvụ ule nyocha na nyocha na-esote ya na ntọala gị. Ụdị ule a nwere ike inye aka kwụọ ụgwọ maka ịghara ịnwale valvụ ahụ na nrụgide ọrụ kachasị njọ.
Mbinye aka valvụ n'oge ule ihe akaebe nwekwara ike ịdekọ oge nzaghachi na stampụ oge, wepụ mkpa maka elekere elekere. Oge nzaghachi na-abawanye bụ ihe ịrịba ama nke mmebi valvụ na ụbara ibu esemokwu iji bugharịa valvụ ahụ. Ọ bụ ezie na enweghị ụkpụrụ gbasara mgbanwe na oge nzaghachi valvụ, ụkpụrụ na-adịghị mma nke mgbanwe site na ule ihe akaebe na ule akaebe na-egosi mfu nke oke nchekwa valvụ na arụmọrụ. Nnwale akaebe valvụ SIS ọgbara ọhụrụ kwesịrị ịgụnye mbinye aka valvụ dịka ihe gbasara omume injinia dị mma.
Ekwesịrị tụọ nrụgide ikuku valvụ n'oge ule ihe akaebe. Ọ bụ ezie na mmiri valvụ maka valvụ nloghachi mmiri bụ ihe na-emechi valvụ ahụ, ike ma ọ bụ ihe ike na-ekpebi ego ole mmiri valve na-ejikọta ya site na nrụgide ọkọnọ valve (kwa iwu Hooke, F = kX). Ọ bụrụ na nrụgide ọkọnọ gị dị ala, mmiri agaghị agbakọ nke ukwuu, ya mere obere ike ga-adị maka ịkwaga valvụ mgbe ọ dị mkpa. Ọ bụ ezie na ọ bụghị gụnyere, ụfọdụ n'ime ihe ndị a ga-atụle n'ịmepụta akụkụ valvụ nke usoro nyocha ihe akaebe ka e nyere na Tebụl 2.
Oge nzipu: Nov-13-2019
