設備檢查概論

1. 設備檢查概論 許世希 980922

2. 目錄 • 前言 • 設備檢查規劃作業準則 • 非破壞性檢測應用 • Fitness for service • 結語

3. 前言 • 設備檢查為設備完整性的一環 • 工場內設備應包括固定設備、轉動設備、控制儀表、土木結構、電力設施及軟体資訊等 • 設備檢查知識應函蓋製程方法、設備設計、檢查技術、腐蝕防制、應力分析及材料科學等 • 設備檢查為有計劃性的實施故風險檢測基準, 腐蝕環路分析，檢測技術等皆有利於檢查的可靠度

4. 火災-爆炸 警報系統 製程控制 製程系統 設備完整性 設備完整性的意義在 確保工廠主要保護層 機能的健全．即製程 設備本身和安全儀控 系統的健全 安全儀控系統 製程設備包含： 壓力容器、儲槽、 管線、泵浦、壓 縮機、洩壓裝置等 安全儀控系統即統 稱之安全連鎖系統

5. 常用Api code • APIAPI 510Pressure Vessel Inspection Code: In-Service Inspection, Rating, Repair, and Alteration Ninth Edition) • APIAPI 570Piping Inspection Code Inspection, Repair, Alteration, and Rerating of In-Service Piping Systems Second Edition • APIRP 571Damage Mechanisms Affecting Fixed Equipment in the Refining Industry First Edition • APIRP 572Inspection of Pressure Vessels (Towers, Drums, Reactors, Heat Exchangers, and Condensers) Second Edition • APIRP 573Inspection of Fired Boilers and Heaters Second Edition • APIRP 574Inspection Practices for Piping System Components Second Edition ( • APIRP 575Guidelines and Methods for Inspection of Existing Atmospheric and Low-Pressure Storage Tanks Second Edition • APIRP 576Inspection of Pressure-Relieving Devices Second Edition • APIRP 577Welding Inspection and Metallurgy First Edition • APIRP 578Material Verification Program for New and Existing Alloy Piping Systems First Edition • APIRP 580Risk-Based Inspection First Edition • APIRP 941Steels for Hydrogen Service at Elevated Temperatures and Pressures in Petroleum Refineries and Petrochemical Plants Seventh Edition • APIRP 945Avoiding Environmental Cracking in Amine Units Third Edition • 598Valve Inspection and Testing Eighth Edition • APISTD 620Design and Construction of Large, Welded, Low-pressure Storage Tanks Eleventh Edition;

6. 大修檢查規劃方法 • 工場大修設備檢查是應用各種檢測和評估技術，對潛在高風險的設備，來決定設備的適用性，以進行必要的銲補、更換維修措施或限制操作條件等措施，以期確保設備安全，降低操作意外風險 • 大修規劃目的在使大修檢查工作掌握重點，使更具效益和效率，基本涵蓋(1)檢測計畫、(2)檢測人員訓練和能力認定（含承攬商）、(3)熟悉判定標準或規範、(4)熟悉檢測資料的應用和(5)檢測資料的保存和更新。

7. 規劃人員及方法 • 大修規畫應會同現場操作、方法工程、檢測、材料、工安和維修等相關人員共同參與討論 • 可採用風險基準檢查理念作為規劃的依據，規劃主要依據法規、失效可能性、設備劣化模式、損壞歷史、操作歷史、破損危害、損失和設計製造等要項，再視實際設備和管線失效風險和損失(火災、爆炸、毒性物質、停爐損失等等)以及大修之人力、時間和經費來訂定設備的優先性和檢查涵蓋範圍。

8. 資料收集 1）由P&ID、P&FD圖、目前操作條件和設計/建造依據之規範，整理各項設備和管線基本資料，其中涵蓋材質、尺寸、壁厚、最小需求厚度、操作溫度、壓力、內容物和熱處理條件等。 2）過去檢查和修護記錄以及追蹤項目彙整 3）操作異常和變化記錄彙整 4）代檢設備彙整 5）延長開放設備彙整

9. 設備和管線系統分類 • 法規/規範/公司規定 • 操作/損壞歷史 • 檢查/維修記錄 • 損傷預測 • 危害分析

10. 設備選定 • 依據資料之彙整和分析結果列出大修檢查的設備和管線。 • 依據實際設備和管線失效風險和損失(火災、爆炸、毒性物質、停爐損失、是否可線上克漏，by-pass操作等等)以及大修之人力、時間和經費來訂定設備的優先性和檢查涵蓋範圍並據此擬定大修檢查重點規劃。

11. 檢查位置和方法 • 設備選定後，應至現場勘查，且清楚圖示檢測位置、範圍和檢查方法。 • 設備檢測位置選定原則為高溫（爐管）、高應力（法蘭溝槽、nozzle）、高腐蝕區、高沖蝕區（彎頭、大小頭、閥體）、滯留區和銲接處、兩相流體液體側、分配管最靠兩側之管線、設備插管和支架保溫等不周全處、低溫設備結冰處和線上監測異常區等等。 • 檢查方法和程序應依循本公司「非破壞檢測作業準則」，必要時應評估採用較先進之檢測設備。 • 擬定檢查作業時程表，明列各檢測點檢測所需配合事項（搭架、拆保溫、除漆、除銹），並送相關配合單位。 • 執行檢查、檢查報告和檢查資料存檔應依循本公司「固定設備檢查作業準則」，檢測規劃書亦應建檔管理

12. 大修檢查計畫之作業 • 由轄區部門主管擔任召集人，原則上於大修停爐前三個月成立「設備檢查規劃小組」 • 召集檢查、修護、技術、煉研所等部門，以風險基準檢查（RBI）理念，並參酌國內外經驗、歷年維修、檢查、操作等紀錄綜合考量下，研訂製程中較可能發生腐蝕損傷之設備部位及管線 • 由檢查部門彙整成「大修檢查計畫」作為大修檢查依據。「大修檢查計畫」規劃明細內容應至少包含設備及管線編號、劣化型態說明、檢查位置、檢查方法、配合事項（如搭架、拆保溫、除銹）、檢查優先順序等項。

13. 檢查位置 設備至少應進行目視及測厚檢查，並應標示檢測位置及示意圖。 製程管線應予以分類，以運用較多之檢查資源於較高潛在損害嚴重性的管線。 對嚴重等級較高之管路應實施更頻繁、更廣泛之檢查，以保障其完整性，使其 能持續安全地操作。 管線分類應考慮洩漏後可能引起安全上與環境上之危害。 原則上，可分成以下二大類： 第一類：一旦洩漏最有可能引起安全或環境等因素上立即的狀況者。 (A) 內容物為可燃性且會自動結凍（auto-refrigerate）導致脆裂者。例如液態氧等。 (B) 壓力狀態下之內容物，而一旦洩漏或釋放後，會迅速氣化、產生蒸氣雲、形成爆炸性混合物者，例如C2、C3、C4之油料及液氨，操作溫度在-4℃至120℃者；會迅速氣化之流體係指常壓下其沸點低於10℃。 (C) 氣相中H2S濃度超過3wt%者。 (D) 氫氣(純度低於80%者)。 第二類：大部分的工場區製程管線與部份區域外管線。 (A) 工場區之一般油料管線，漏出時會逐漸蒸發者，例如操作溫度在閃火點以 上之油料管線。 (B) 含氫氣純度達80%以上者、燃料氣、天然氣、高壓蒸汽之管線。

14. 厚度檢測點位置之決定 檢查或管轄部門應對各管路系統可能存在之下列特殊環境與腐蝕型 態特別注意，並列為厚度檢測與其他檢查之重點。 (A) 注入處。 (B) 滯流區(Deadlegs)。 (C) 保溫層下之腐蝕(CUI)。 (D) 土壤介面處。 (E) 蒸汽凝結處、銨鹽冷凝處、高溫硫化物環境下不同等級的碳 鋼接合處、多相流體混合交會處、沈積物（如污泥、結晶、 結焦等）下。 (F) 沖蝕及沖蝕與腐蝕之加成作用處。 a). 控制閥下游，特別是流體會氣化者。 b). 流孔板下游。 c). 泵浦出口。 d). 流體流向改變處，如彎頭之內緣及外緣。 e). 干擾流體流動導致產生擾流處（如銲道、溫度計插入 點、法蘭等）之下游。

15. 存有以下條件，宜輔以其他非破壞檢測 (A) 應力腐蝕裂紋產生區。 a). 沃斯田鐵系不銹鋼，在保溫層或沈積物下、或墊圈及其他之間隙等部位， 因濕氣及氯化物造成之氯化物應力腐蝕。 b). 敏化之沃斯田鐵系合金鋼材，遭受硫化物、凝結濕氣或氧氣導致之聚硫酸(Polythionic acid)應力腐蝕。 c). 苛性鹼脆化應力腐蝕。 d). 未經應力釋除熱處理管線之胺液(Amine)應力腐蝕。 e). 碳酸鹽應力腐蝕。 f). 含H2S酸水系統管線之應力腐蝕。 g). 氫起泡及氫誘發破裂（HIC）。 (B) 內襯或沈積物下之腐蝕。 (C) 疲勞裂紋常發生在應力集中之處，例如歧管或材料熱膨脹係數不同材料之之接合焊銲道。 (D) 潛變為材料因時間、溫度及應力三者之影響而劣化之現象。在溫度過高之情形下，材料會發生機械性質與顯微組織之變化導致材料強度降低。1.25Cr低合金鋼在482℃(900℉)以上有發生潛變裂紋。 (E) 低合金鋼（特別是2.25Cr-1Mo合金鋼材料）及肥粒鐵系不銹鋼材料因有回火脆化之現象，應留意其低溫脆裂之問題。 (F) 超冷之溫度下輸送水或水溶液，易因結冰使流體體積膨脹，造成管線破裂

16. 檢查報告 • 大修期間之各項檢查工作完成後，應立即針對檢查結果予以初步判定 • 大修結束後將檢查結果編成報告建檔追蹤，內容應包含初步檢查通知單編號、檢查項目、處理情形

17. 非破壞檢測運用 • 定義：利用物理或機械力方法或技術，在不破壞材料情況下，檢測材料的缺陷、物理或機械性質的技術如材料厚度、鍍膜厚度、導電率、彈性係數、材質等。 • 常用代號：NDT、NDE、NDI。 • 常用非破壞檢測方法：液滲檢測(PT)、磁粒檢測(MT)、射線檢測(RT)、超音波檢測(UT)、渦電流檢測(ET)、目視檢測(VT)、音洩檢測(AE)等。

18. PROFILE RT • 係以一直徑1"之小鋼珠垂直平放於管壁上，利用設線檢測原理使小鋼珠與管壁同時成像於底片上，以判定管壁是否減薄；檢測時需注意底片、射源之擺設，對小鋼珠及管壁而言，角度不得傾斜，否則成像時將導致小鋼珠變形或影像重疊而影響判定；至於射源至底片距離以小鋼珠不得放大為原則。

19. Pipeline Inspection NDT is used to inspect pipelines to prevent leaks that could damage the environment. Visual inspection, radiography and electromagnetic testing are some of the NDT methods used. Remote visual inspection using a robotic crawler. Magnetic flux leakage inspection. This device, known as a pig, is placed in the pipeline and collects data on the condition of the pipe as it is pushed along by whatever is being transported. Radiography of weld joints.

20. 洩漏檢測 LT (1)氣泡測漏 (2)壓力變化測漏 (3)超音波測漏 (4)化學滲透劑測漏 (5)鹵素測漏 (6)質譜儀測漏

21. 不同測漏法靈敏度的比較

22. 材質辨識(PMI) • 材質初步分析(適用於合金鋼、不銹鋼)以移動式分光儀為之。唯受限於不能檢驗曲度過大之工件，且受檢面積需50mm*50mm以上，方能便於用槍，又因其一經移動則需重新校正，加上裝備笨重不利高空作業。 • 目前已有多種pmi儀器，使用同位素法輕巧方便。

23. 真空試漏 • 位置：底板焊道及母材部分或頂板焊道。 • 時機：考慮各項鋼板之腐蝕有洩漏時。 • 實施方式：在可疑位置塗上肥皂液或專用溶液，利用真空試漏箱緊壓此區域，真空開口邊緣與儲槽板之間放置一層軟的墊圈，經真空泵抽真空至少表壓負4psig以上真空度，如有洩漏時，可由真空箱頂的玻璃看出有明顯的泡泡產生

24. Rapid Tube Inspectionusing Eddy Current (ET) or Remote Field (RFT) methods • Characteristics of the ET technique • High speed method. Inspects 500-800, 10m tubes per day. • 100% inspection of the tube. • Little surface preparation (cleaning). • Color coded reporting for convenient results overview.

25. Pipe with damage Probe Signals produced by various amounts of corrosion thinning. Heat exchanger Inspection Periodically, refinery plants are shutdown for inspection. Inspectors feed eddy current probes into heat exchanger tubes to check for corrosion damage.

26. Manual Ultrasonic (UT) Weld Inspection • Quick and direct results. • No protection against radiation required, neither interruption of other peoples work. • In-service inspection. • Inspection of complex geometry welds with profile analysis of the weld using a PC. • Inspections performed according to international standards ASME, EN etc. • Final technical report that contains position, depth and type information of discontinuity. • Storage of the discontinuities signals and inspection parameters. • Sensitivity in critical discontinuities detection (e.g. cracking).

27. Automated Ultrasonic (UT) Tube Corrosion Mapping • Inspection speed up to 100mm per second, depending on the desirable resolution. • The probe for data recording is inserted completely automated with a 300mm per second speed depending on the required measurement precision. • Complete 2 or 3 axes recording (C-Scan and B-Scan) with capability to export the data on Excel worksheet for further analysis. • Inspects tubes with diameters from 12mm up to 76mm. • Thickness and corrosion mapping and/or inspection for other types of imperfections.

28. Ultrasonic Thickness Measurements • Quick measurements with direct results. • High precision measurements. • The inspected object can be in-service. • No particular surface preparation required. • Measurements can be made without removal of the paint. • Measurements on high temperature surfaces possible

29. Guided Ultrasonic Waves Pipe Inspection • A ring with the transducers is placed around the pipeNo couplant is required • Usually no surface preparation required • Instrumentation is fully portable • Guided waves are sent in each direction • Data are collected and stored in the portable instrument • Reflections are analysed and results reported immediately after the test • Long sections of pipe can be examined from one location, e.g. 30m on either side of the ring • Capabilities • Each test is completed within minutes including results • Can be performed at elevated temperatures without taking the pipe out of service up to 125℃. • 100% of the pipe is inspected (within the diagnostic length of a test) • Pulse echo type operation provides information on feature position and approximate size • Sophisticated analysis aids interpretation of results • Minimum insulation removal for testing (1m) • Difficult-to-inspect areas (such as roadways) can be screened for defects

30. Testing Cryogenic Tank Walls with AE • Global Monitoring - Sensors detect AE signals from considerable distances, making this method ideal for global monitoring of large vessels and systems. Identified problem areas can then be inspected using other NDT methods. • Minor Disturbance of Insulation - Only small holes in insulation are required for sensor mounting. • On-Line Testing. Opening a tank introduces oxygen into the tank. When the tank is put back into service the corrosion process starts all over again. • Cost Reduction. In ammonia applications, it can cost up to $1,000,000 just for a nitrogen purge.. The use of AE can reduce plant maintenance costs considerably, while increasing the information available about plant integrity. Plant downtime for inspection is also minimized. • Rapid Inspection - The actual AE test takes a matter of hours, and in some cases, considerably less. No comparable method can provide 100% volumetric inspection in the same amount of time. • Permanent Record of Test - Data is digitized and stored on disk, providing a permanent record of

31. Leak Detection using Acoustic Emission

32. On-Line Tank Floor Inspection with TANKPAC • No Need to Empty or Clean the Tank • 100% Floor Inspection • Verified Reliability • Inspection and Evaluation of Annular Ring • Immediate Results • Rapid testing: 50 meter tank in one day • Identify tanks that need inspection and repair • Leave good tanks on-line and save the shut-down and cleaning costs

33. Fitness-For-ServiceAPI 579-1/ASME FFS-1 • Fitness-For-Service (FFS) assessments are quantitative engineering evaluations that are performed to demonstrate the structural integrity of an in-service component that may contain a flaw or damage. • This Standard provides guidance for conducting FFS assessments using methodologies specifically prepared for pressurized equipment. The guidelines provided in this Standard can be used to make run-repair-replace decisions to help determine if pressurized equipment containing flaws that have been identified by inspection can continue to operate safely for some period of time. • These FFS assessments are currently recognized and referenced by the API Codes and Standards (510, 570, & 653), and by NB-23 as suitable means for evaluating the structural integrity of pressure vessels, piping systems and storage tanks where inspection has revealed degradation and flaws in the equipment.

34. The Fitness-For-Service assessment procedures in this Standard cover both the present integrity of the component given a current state of damage and the projected remaining life. • Assessment techniques are included to evaluate flaws including: general and localized corrosion, widespread and localized pitting, blisters and hydrogen damage, weld misalignment and shell distortions, crack-like flaws including environmental cracking, laminations, dents and gouges, and remaining life assessment procedures for components operating in the creep range. • In addition, evaluation techniques are provided for condition assessment of equipment including resistance to brittle fracture, long-term creep damage, and fire damage.

36. Fitness-For-Service assessment procedure • STEP 1 – Flaw and Damage Mechanism Identification: • STEP 2 – Applicability and Limitations of the FFS Assessment Procedures: • STEP 3 – Data Requirements: • STEP 4 – Assessment Techniques and Acceptance Criteria: • STEP 5 – Remaining Life Evaluation: • STEP 6 – Remediation: • STEP 7 – In-Service Monitoring: • STEP 8 – Documentation

37. Applicability and Limitations of the FFS Assessment Procedures • The FFS assessment procedures in this Standard were developed to evaluate the pressure boundaries of pressure vessels, boiler components, piping, and shell courses of storage tanks with a flaw resulting from single or multiple damage mechanisms. • The concepts presented in this Standard may also be used for the assessment of non-pressure-boundary components such as supports. • Fitness-For-Service procedures for fixed and floating roof structures, and bottom plates of tanks are covered in Part 2 of API 653.

38. Assessment Techniques and Acceptance Criteria • Level 1 Assessment: may be performed either by plant inspection or engineering personnel • Level 2 Assessment: would typically be conducted by plant engineers,or engineering specialists experienced and knowledgeable in performing FFS assessments. • Level 3 Assessment: primarily intended for use by engineering specialists experienced and knowledgeable in performing FFS assessments.

39. 結語 • 設備檢查能降低工場意外停爐的事件，但設備檢查非萬能丹，平常巡檢最重要 • 設備檢查的可靠度影響到檢查的品質，所以專業檢查人員必須Qualify • 發覺設備缺失，可利用FFS方法評估、改善、並監控