Alarm sensor geter pikeun (ＨＯＭＥ)

Uji bukti mangrupikeun bagian integral tina pangropéa integritas kaamanan sistem instrumentasi kaamanan (SIS) sareng sistem anu aya hubunganana sareng kaamanan (contona alarm kritis, sistem seuneu & gas, sistem interlock instrumentasi, jsb.). Uji bukti mangrupikeun tés périodik pikeun ngadeteksi kagagalan bahaya, nguji fungsi anu aya hubunganana sareng kaamanan (contona reset, bypasses, alarm, diagnostik, shutdown manual, jsb.), sareng mastikeun sistem nyumponan standar perusahaan sareng éksternal. Hasil tina uji bukti ogé mangrupikeun ukuran efektivitas program integritas mékanis SIS sareng reliabilitas lapangan sistem.

Prosedur uji bukti ngawengku léngkah-léngkah uji ti mimiti kéngingkeun idin, ngadamel béwara sareng ngeureunkeun sistem tina panggunaan pikeun diuji dugi ka mastikeun uji anu komprehensif, ngadokumentasikeun uji bukti sareng hasilna, nempatkeun deui sistem dina panggunaan, sareng meunteun hasil uji ayeuna sareng hasil uji bukti sateuacana.

ANSI/ISA/IEC 61511-1, Klausul 16, ngawengku uji bukti SIS. Laporan téknis ISA TR84.00.03 – “Integritas Mékanis Sistem Instrumén Kasalametan (SIS),” ngawengku uji bukti sareng ayeuna nuju dirévisi kalayan vérsi énggal anu dipiharep kaluar teu lami deui. Laporan téknis ISA TR96.05.02 – “Uji Bukti In-situ Katup Otomatis” ayeuna nuju dikembangkeun.

Laporan HSE Inggris CRR 428/2002 – “Prinsip-prinsip pikeun uji bukti sistem anu diinstruméntasikeun kaamanan dina industri kimia” nyayogikeun inpormasi ngeunaan uji bukti sareng naon anu dilakukeun ku perusahaan di Inggris.

Prosedur uji bukti dumasar kana analisis modeu kagagalan bahaya anu dipikanyaho pikeun unggal komponén dina jalur perjalanan fungsi instrumentasi kaamanan (SIF), fungsi SIF salaku sistem, sareng kumaha (sareng upami) nguji modeu kagagalan bahaya. Pangwangunan prosedur kedah dimimitian dina fase desain SIF kalayan desain sistem, pamilihan komponén, sareng nangtukeun iraha sareng kumaha uji bukti. Instrumen SIS ngagaduhan tingkat kasusah uji bukti anu béda-béda anu kedah dipertimbangkeun dina desain, operasi sareng pangropéa SIF. Salaku conto, méter orifice sareng pemancar tekanan langkung gampang diuji tibatan méter aliran massa Coriolis, méter mag atanapi sénsor tingkat radar through-the-air. Aplikasi sareng desain klep ogé tiasa mangaruhan kalengkepan uji bukti klep pikeun mastikeun yén kagagalan bahaya sareng anu mimiti kusabab degradasi, panyumbatan atanapi kagagalan anu gumantung kana waktos henteu nyababkeun kagagalan kritis dina interval uji anu dipilih.

Sanaos prosedur uji bukti biasana dikembangkeun salami fase rékayasa SIF, éta ogé kedah diulas ku Otoritas Téknis SIS di lokasi, Operasi sareng teknisi instrumen anu bakal ngalakukeun uji coba. Analisis kasalametan padamelan (JSA) ogé kedah dilakukeun. Penting pikeun kéngingkeun dukungan ti pabrik ngeunaan uji coba naon anu bakal dilakukeun sareng iraha, sareng kalayakan fisik sareng kaamananana. Salaku conto, teu aya gunana pikeun nangtukeun uji coba partial-stroke nalika grup Operasi henteu satuju pikeun ngalakukeunana. Disarankeun ogé yén prosedur uji bukti diulas ku ahli subjek mandiri (SME). Uji coba has anu diperyogikeun pikeun uji coba fungsi lengkep diilustrasikeun dina Gambar 1.

Sarat uji bukti fungsi lengkep Gambar 1: Spésifikasi uji bukti fungsi lengkep pikeun fungsi anu diinstruméntasikeun kaamanan (SIF) sareng sistem anu diinstruméntasikeun kaamanan (SIS) na kedah ngajelaskeun atanapi ngarujuk kana léngkah-léngkah sacara runtuyan ti persiapan uji sareng prosedur uji dugi ka béwara sareng dokuméntasi.

Gambar 1: Spésifikasi tés bukti fungsi lengkep pikeun fungsi anu diinstruméntasikeun kaamanan (SIF) sareng sistem anu diinstruméntasikeun kaamanan (SIS) na kedah ngajelaskeun atanapi ngarujuk kana léngkah-léngkah sacara runtuyan ti persiapan tés sareng prosedur tés dugi ka béwara sareng dokuméntasi.

Uji bukti mangrupikeun tindakan pangropéa anu direncanakeun anu kedah dilakukeun ku personil anu kompeten anu dilatih dina uji SIS, prosedur bukti, sareng puteran SIS anu bakal diuji. Kedah aya tinjauan prosedur sateuacan ngalaksanakeun uji bukti awal, sareng eupan balik ka Otoritas Téknis SIS situs saatosna pikeun perbaikan atanapi koreksi.

Aya dua modeu kagagalan utama (aman atanapi bahaya), anu dibagi deui kana opat modeu—bahaya teu kadeteksi, bahaya kadeteksi (ku diagnostik), aman teu kadeteksi sareng aman kadeteksi. Istilah kagagalan bahaya sareng bahaya teu kadeteksi dianggo silih genti dina tulisan ieu.

Dina uji bukti SIF, urang utamina resep kana modeu kagagalan anu bahaya sareng teu kadeteksi, tapi upami aya diagnostik pangguna anu ngadeteksi kagagalan anu bahaya, diagnostik ieu kedah diuji buktina. Catet yén teu sapertos diagnostik pangguna, diagnostik internal alat biasana teu tiasa divalidasi salaku fungsional ku pangguna, sareng ieu tiasa mangaruhan filosofi uji buktina. Nalika kiridit pikeun diagnostik dicandak dina itungan SIL, alarm diagnostik (contona alarm di luar jangkauan) kedah diuji salaku bagian tina uji buktina.

Modeu kagagalan tiasa dibagi deui kana anu diuji nalika uji bukti, anu henteu diuji, sareng kagagalan anu mimiti atanapi kagagalan anu gumantung kana waktos. Sababaraha modeu kagagalan anu bahaya tiasa henteu diuji langsung pikeun sababaraha alesan (contona kasusah, kaputusan rékayasa atanapi operasional, kabodoan, inkompetensi, kalalaian atanapi komisi kasalahan sistematis, probabilitas kajadian anu handap, jsb.). Upami aya modeu kagagalan anu dipikanyaho anu moal diuji, kompensasi kedah dilakukeun dina desain alat, prosedur uji, panggantian atanapi ngawangun deui alat périodik, sareng/atanapi uji inferensial kedah dilakukeun pikeun ngaminimalkeun pangaruh kana integritas SIF tina henteu nguji.

Kagagalan anu mimiti nyaéta kaayaan anu parah sahingga kagagalan anu kritis sareng bahaya tiasa dipiharep kajadian upami tindakan korektif henteu dilaksanakeun dina waktos anu pas. Biasana dideteksi ku ngabandingkeun kinerja sareng tés bukti patokan anyar atanapi awal (contona tanda tangan klep atanapi waktos réspon klep) atanapi ku pamariksaan (contona port prosés anu dipasang). Kagagalan anu mimiti biasana gumantung kana waktos — beuki lami alat atanapi rakitan dianggo, beuki parah éta; kaayaan anu ngagampangkeun kagagalan acak janten langkung kamungkinan, port prosés dipasang atanapi paningkatan sénsor kana waktos, umur mangpaat parantos béak, jsb. Ku alatan éta, beuki panjang interval tés bukti, beuki kamungkinan kagagalan anu mimiti atanapi gumantung kana waktos. Sagala panyalindungan ngalawan kagagalan anu mimiti ogé kedah diuji buktina (ngabersihkeun port, ngalacak panas, jsb.).

Prosedur kedah ditulis pikeun nguji bukti pikeun kagagalan anu bahaya (anu teu kadeteksi). Téhnik analisis modeu sareng pangaruh kagagalan (FMEA) atanapi analisis modeu, pangaruh sareng diagnostik kagagalan (FMEDA) tiasa ngabantosan ngaidentipikasi kagagalan anu bahaya sareng teu kadeteksi, sareng dimana cakupan uji bukti kedah ditingkatkeun.

Seueur prosedur uji bukti anu ditulis dumasar kana pangalaman sareng témplat tina prosedur anu tos aya. Prosedur énggal sareng SIF anu langkung rumit meryogikeun pendekatan anu langkung direkayasa nganggo FMEA/FMEDA pikeun nganalisis kagagalan anu bahaya, nangtukeun kumaha prosedur uji bakal atanapi henteu nguji kagagalan éta, sareng cakupan uji éta. Diagram blok analisis modeu kagagalan tingkat makro pikeun sénsor dipidangkeun dina Gambar 2. FMEA biasana ngan ukur kedah dilakukeun sakali pikeun jinis alat khusus sareng dianggo deui pikeun alat anu sami kalayan mertimbangkeun kamampuan layanan prosés, pamasangan sareng uji coba situsna.

Analisis kagagalan tingkat makro Gambar 2: Diagram blok analisis modeu kagagalan tingkat makro ieu pikeun sensor sareng pemancar tekanan (PT) nunjukkeun fungsi utama anu biasana bakal dibagi kana sababaraha analisis kagagalan mikro pikeun ngajelaskeun sacara lengkep poténsi kagagalan anu kedah diatasi dina tés fungsi.

Gambar 2: Diagram blok analisis modeu kagagalan tingkat makro ieu pikeun sensor sareng pemancar tekanan (PT) nunjukkeun fungsi utama anu biasana bakal dibagi kana sababaraha analisis kagagalan mikro pikeun ngajelaskeun sacara lengkep poténsi kagagalan anu kedah diatasi dina tés fungsi.

Persentase kagagalan anu dipikanyaho, bahaya, sareng teu kadeteksi anu diuji buktina disebut cakupan uji bukti (PTC). PTC umumna dianggo dina itungan SIL pikeun "ngimbangan" kagagalan pikeun nguji SIF sacara langkung lengkep. Jalma-jalma gaduh kapercayaan anu salah yén kusabab aranjeunna parantos mertimbangkeun kurangna cakupan tés dina itungan SIL na, aranjeunna parantos ngarancang SIF anu tiasa dipercaya. Kanyataanana nyaéta, upami cakupan tés anjeun 75%, sareng upami anjeun ngitung angka éta kana itungan SIL anjeun sareng nguji hal-hal anu anjeun parantos uji langkung sering, 25% tina kagagalan bahaya masih tiasa kajantenan sacara statistik. Abdi pasti henteu hoyong aya dina 25% éta.

Laporan persetujuan FMEDA sareng manual kaamanan pikeun alat biasana nyayogikeun prosedur uji bukti minimum sareng cakupan uji bukti. Ieu ngan ukur nyayogikeun pituduh, sanés sadaya léngkah uji anu diperyogikeun pikeun prosedur uji bukti anu komprehensif. Jenis analisis kagagalan anu sanés, sapertos analisis tangkal kasalahan sareng pangropéa anu berpusat kana reliabilitas, ogé dianggo pikeun nganalisis kagagalan anu bahaya.

Tés buktina tiasa dibagi kana tés fungsional pinuh (tungtung-ka-tungtung) atanapi uji fungsional parsial (Gambar 3). Tés fungsional parsial umumna dilakukeun nalika komponén SIF gaduh interval tés anu béda dina itungan SIL anu henteu saluyu sareng rencana shutdown atanapi turnaround. Penting yén prosedur tés bukti fungsional parsial tumpang tindih supados babarengan nguji sadaya fungsi kaamanan SIF. Kalayan tés fungsional parsial, tetep disarankeun yén SIF gaduh tés bukti awal tungtung-ka-tungtung, sareng anu salajengna salami turnaround.

Tés bukti parsial kedahna jumlahna Gambar 3: Tés bukti parsial gabungan (handap) kedah ngawengku sadaya fungsi tina tés bukti fungsional lengkep (luhur).

Gambar 3: Uji bukti parsial gabungan (handap) kedah ngawengku sadaya fungsi uji bukti fungsional lengkep (luhur).

Uji bukti parsial ngan ukur nguji perséntase tina modeu kagagalan alat. Conto umum nyaéta uji klep stroke parsial, dimana klep dipindahkeun sakedik (10-20%) pikeun mastikeun yén éta henteu macét. Ieu ngagaduhan cakupan uji bukti anu langkung handap tibatan uji bukti dina interval uji primér.

Prosedur uji bukti tiasa bénten-bénten dina kompleksitasna numutkeun kompleksitas SIF sareng filosofi prosedur uji perusahaan. Sababaraha perusahaan nyerat prosedur uji léngkah-léngkah anu lengkep, sedengkeun anu sanésna gaduh prosedur anu cukup pondok. Rujukan kana prosedur sanés, sapertos kalibrasi standar, kadang dianggo pikeun ngirangan ukuran prosedur uji bukti sareng pikeun ngabantosan mastikeun konsistensi dina uji. Prosedur uji bukti anu saé kedah nyayogikeun detil anu cekap pikeun mastikeun yén sadaya uji parantos réngsé sareng didokumentasikeun kalayan leres, tapi sanés seueur detil anu nyababkeun teknisi hoyong ngalangkungan léngkah-léngkah. Ngagaduhan teknisi, anu tanggung jawab pikeun ngalaksanakeun léngkah uji, ngamimitian léngkah uji anu réngsé tiasa ngabantosan mastikeun yén uji bakal dilakukeun kalayan leres. Penandatanganan uji bukti anu réngsé ku Pengawas Instrumen sareng wawakil Operasi ogé bakal nekenkeun pentingna sareng mastikeun uji bukti anu réngsé kalayan leres.

Eupan balik ti téknisi kedah teras dipénta pikeun ngabantosan ningkatkeun prosedur. Kasuksésan prosedur uji bukti seueur pisan aya dina panangan téknisi, janten usaha kolaboratif disarankeun pisan.

Kaseueuran uji bukti biasana dilakukeun sacara offline nalika shutdown atanapi turnaround. Dina sababaraha kasus, uji bukti tiasa diperyogikeun dilakukeun sacara online nalika dijalankeun pikeun nyumponan itungan SIL atanapi sarat sanésna. Uji online meryogikeun perencanaan sareng koordinasi sareng Operasi pikeun ngamungkinkeun uji bukti dilakukeun sacara aman, tanpa gangguan prosés, sareng tanpa nyababkeun spurious trip. Ngan ukur peryogi hiji spurious trip pikeun ngagunakeun sadaya attaboy anjeun. Salila jinis uji ieu, nalika SIF henteu sayogi sapinuhna pikeun ngalaksanakeun tugas kaamananana, 61511-1, Klausul 11.8.5, nyatakeun yén "Ukuran kompensasi anu mastikeun operasi anu aman terus-terusan kedah disayogikeun saluyu sareng 11.3 nalika SIS aya dina bypass (perbaikan atanapi uji)." Prosedur manajemen kaayaan anu teu normal kedah dibarengan ku prosedur uji bukti pikeun ngabantosan mastikeun ieu dilakukeun kalayan leres.

SIF biasana dibagi jadi tilu bagian utama: sénsor, pangleyur logika, sareng élémen ahir. Aya ogé alat bantu anu biasana tiasa dihubungkeun dina unggal tilu bagian ieu (contona panghalang IS, amp trip, relay interposing, solenoid, jsb.) anu ogé kedah diuji. Aspék kritis tina uji bukti unggal téknologi ieu tiasa dipendakan dina sidebar, "Nguji sénsor, pangleyur logika, sareng élémen ahir" (di handap).

Aya sababaraha hal anu langkung gampil diuji tibatan anu sanésna. Seueur téknologi aliran sareng tingkat modéren sareng sababaraha anu langkung lami aya dina kategori anu langkung sesah. Ieu kalebet flowmeter Coriolis, vortex meter, mag meter, radar through-the-air, level ultrasonik, sareng saklar prosés in-situ, kanggo nyebatkeun sababaraha. Untungna, seueur di antarana ayeuna gaduh diagnostik anu ditingkatkeun anu ngamungkinkeun uji anu langkung saé.

Kasusah dina nguji alat sapertos kitu di lapangan kedah dipertimbangkeun dina desain SIF. Gampang pikeun rékayasa milih alat SIF tanpa mertimbangkeun sacara serius naon anu diperyogikeun pikeun nguji alat éta, sabab éta sanés jalma anu nguji éta. Ieu ogé leres pikeun uji coba partial-stroke, anu mangrupikeun cara umum pikeun ningkatkeun probabilitas rata-rata SIF tina kagagalan nalika paménta (PFDavg), tapi engkéna Operasi pabrik henteu hoyong ngalakukeun éta, sareng seringna henteu. Salawasna nyayogikeun pangawasan pabrik kana rékayasa SIF dina hal uji coba bukti.

Tés buktina kedah ngawengku pamariksaan pamasangan sareng perbaikan SIF sakumaha anu diperyogikeun pikeun nyumponan 61511-1, Klausul 16.3.2. Kedah aya pamariksaan akhir pikeun mastikeun sadayana parantos dipasang, sareng mariksa deui yén SIF parantos disimpen deui kalayan leres kana layanan prosés.

Nulis sareng ngalaksanakeun prosedur tés anu saé mangrupikeun léngkah penting pikeun mastikeun integritas SIF salami umurna. Prosedur tés kedah nyayogikeun detil anu cekap pikeun mastikeun yén tés anu diperyogikeun dilaksanakeun sacara konsisten sareng aman sareng didokumentasikeun. Kagagalan bahaya anu henteu diuji ku tés bukti kedah dikompensasi pikeun mastikeun yén integritas kaamanan SIF dijaga kalayan cekap salami umurna.

Nulis prosedur uji bukti anu saé meryogikeun pendekatan anu logis pikeun analisis rékayasa tina poténsi kagagalan anu bahaya, milih sarana, sareng nyerat léngkah-léngkah uji bukti anu aya dina kamampuan uji pabrik. Sapanjang jalan, kéngingkeun dukungan pabrik di sadaya tingkatan pikeun uji coba, sareng latih teknisi pikeun ngalaksanakeun sareng ngadokumentasikeun uji bukti ogé ngartos pentingna uji coba. Tulis pitunjuk sapertos anjeun teknisi instrumen anu kedah ngalakukeun padamelan éta, sareng yén kahirupan gumantung kana kéngingkeun uji coba anu leres, sabab leres.

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 biasana dibagi jadi tilu bagian utama, nyaéta sénsor, pangleyur logika, jeung unsur ahir. Biasana ogé aya alat bantu anu bisa disambungkeun dina unggal tilu bagian ieu (misalna panghalang IS, amp trip, relay interposing, solenoid, jsb.) anu ogé kudu diuji.

Tés bukti sénsor: Tés bukti sénsor kedah mastikeun yén sénsor tiasa ngaraos variabel prosés dina rentang pinuhna sareng ngirimkeun sinyal anu pas ka solver logika SIS pikeun évaluasi. Sanaos henteu kalebet, sababaraha hal anu kedah dipertimbangkeun dina nyiptakeun bagian sénsor tina prosedur tés bukti dibéré dina Tabel 1.

Tés bukti pamecah logika: Nalika tés bukti fungsi lengkep dilakukeun, bagian pamecah logika dina ngalaksanakeun tindakan kaamanan SIF sareng tindakan anu aya hubunganana (contona alarm, reset, bypass, diagnostik pangguna, redundansi, HMI, jsb.) diuji. Tés bukti fungsi parsial atanapi sapotong-sapotong kedah ngalaksanakeun sadaya tés ieu salaku bagian tina tés bukti tumpang tindih individu. Pabrikan pamecah logika kedah gaduh prosedur tés bukti anu disarankeun dina manual kaamanan alat. Upami henteu sareng sahenteuna, kakuatan pamecah logika kedah didaur ulang, sareng register diagnostik pamecah logika, lampu status, voltase catu daya, tautan komunikasi sareng redundansi kedah dipariksa. Pamariksaan ieu kedah dilakukeun sateuacan tés bukti fungsi lengkep.

Tong nganggap yén parangkat lunak éta téh salawasna saé sareng logikana teu kedah diuji saatos uji bukti awal sabab parobihan parangkat lunak sareng perangkat keras anu teu didokumentasikeun, teu diidinan sareng teu diuji sareng apdet parangkat lunak tiasa nyusup kana sistem kana waktosna sareng kedah dipertimbangkeun kana filosofi uji bukti anjeun sacara umum. Manajemén log parobihan, pangropéa, sareng révisi kedah ditinjau pikeun mastikeun yén éta mutahir sareng dijaga kalayan leres, sareng upami tiasa, program aplikasi kedah dibandingkeun sareng cadangan pangénggalna.

Ogé kedah ati-ati pikeun nguji sadaya fungsi bantu sareng diagnostik pemecah logika pangguna (contona anjing pengawas, tautan komunikasi, alat kaamanan siber, jsb.).

Uji bukti élémen ahir: Kaseueuran élémen ahir nyaéta klep, nanging, starter motor alat anu muter, drive kecepatan variabel sareng komponén listrik sanés sapertos kontaktor sareng pemutus sirkuit ogé dianggo salaku élémen ahir sareng modeu kagagalanna kedah dianalisis sareng diuji buktina.

Modeu kagagalan utama pikeun klep nyaéta macét, waktos réspon laun teuing atanapi gancang teuing, sareng bocor, anu sadayana kapangaruhan ku antarmuka prosés operasi klep nalika waktos trip. Sanaos nguji klep dina kaayaan operasi mangrupikeun kasus anu paling dipikahoyong, Operasi umumna bakal ngalawan trip SIF nalika pabrik beroperasi. Kaseueuran klep SIS biasana diuji nalika pabrik turun dina tekanan diferensial nol, anu mangrupikeun kaayaan operasi anu paling teu nungtut. Pangguna kedah waspada kana tekanan diferensial operasional anu paling parah sareng épék degradasi klep sareng prosés, anu kedah dipertimbangkeun kana desain sareng ukuran klep sareng aktuator.

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).

Suhu lingkungan ogé tiasa mangaruhan beban gesekan klep, janten klep uji dina cuaca haneut umumna bakal janten beban gesekan anu paling saeutik upami dibandingkeun sareng operasi cuaca tiis. Hasilna, uji bukti klep dina suhu anu konsisten kedah dipertimbangkeun pikeun nyayogikeun data anu konsisten pikeun uji inferensial pikeun nangtukeun degradasi kinerja klep.

Katup kalayan posisi pinter atanapi pangontrol klep digital umumna gaduh kamampuan pikeun nyiptakeun tanda tangan klep anu tiasa dianggo pikeun ngawas degradasi dina kinerja klep. Tanda tangan klep dasar tiasa dipénta salaku bagian tina pesenan pameseran anjeun atanapi anjeun tiasa nyiptakeunana nalika tés bukti awal pikeun janten garis dasar. Tanda tangan klep kedah dilakukeun pikeun muka sareng nutup klep. Diagnostik klep canggih ogé kedah dianggo upami sayogi. Ieu tiasa ngabantosan anjeun terang upami kinerja klep anjeun mudun ku ngabandingkeun tanda tangan klep tés bukti salajengna sareng diagnostik anjeun. Tés jinis ieu tiasa ngabantosan ngimbangan henteu nguji klep dina tekanan operasi anu paling parah.

Tanda tangan klep nalika uji bukti ogé tiasa ngarékam waktos réspon nganggo cap waktos, ngaleungitkeun kabutuhan stopwatch. Ningkatna waktos réspon mangrupikeun tanda karusakan klep sareng ningkatna beban gesekan pikeun mindahkeun klep. Sanaos teu aya standar ngeunaan parobahan dina waktos réspon klep, pola parobahan négatip tina uji bukti ka uji bukti nunjukkeun poténsi leungitna margin kaamanan sareng kinerja klep. Uji bukti klep SIS modéren kedah ngalebetkeun tanda tangan klep salaku prakték rékayasa anu saé.

Tekanan suplai hawa instrumen klep kedah diukur nalika uji bukti. Sanaos pegas klep pikeun klep pamulangan pegas anu nutup klep, gaya atanapi torsi anu kalibet ditangtukeun ku sabaraha pegas klep dikomprés ku tekanan suplai klep (per Hukum Hooke, F = kX). Upami tekanan suplai anjeun rendah, pegas moal seueur dikomprés, ku kituna gaya anu sayogi pikeun mindahkeun klep nalika diperyogikeun. Sanaos henteu kalebet, sababaraha hal anu kedah dipertimbangkeun dina nyiptakeun bagian klep tina prosedur uji bukti dipasihkeun dina Tabel 2.