• Title/Summary/Keyword: Qualitative inspection

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Development of Program for Qualitative Risk Based Inspection (RBI) using API-581 (API-581에 의한 정성적 위험기반검사(RBI) 프로그램 개발)

  • 이헌창;유준;김환주;김태옥
    • Journal of the Korea Safety Management & Science
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    • v.6 no.1
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    • pp.49-60
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    • 2004
  • Industrial facilities are becoming more complex and various with rapidly developing technologies. A number of installations and equipments are increased to improve productivity, and they are operated under the condition of high temperature and pressure. They are continuously repaired, replaced or abolished because of the deterioration with time, but their repair and replacement are not easy for economical and environmental concerns. If possible, the deteriorating equipments should be inspected and repaired effectively considering the state of maintenance and preservation, economic efficiency, and safety. That's where RBI(Risk Based Inspection) fits in. Even if RBI technology has been known among specialists, there were no tools readily available and it was hard to practice and apply RBI in industrial inspection and safety management. In the development of the qualitative RBI, the overall algorithm adopted API-581 BRD. The qualitative RBI program was developed to search the appling process.

Qualitative RBI Analysis in Considered with Uncertain Variables by Probabilistic Distribution (확률분포에 따른 불확실한 변수를 고려한 위험도기반의 정성적 평가)

  • Heo, Ho-Jin;Jeong, Jae-Uk;Kim, Joo-Dong;Choi, Jae-Boong;Choi, Song-Chun;Hwang, In-Ju
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.25 no.2
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    • pp.70-78
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    • 2013
  • Plants which are having conditions of high temperature and pressure always are exposed to danger. In order to prevent unexpected accidents, safety management that can effectively and appropriately examine facilities is required in plant operation. RBI(Risk-Based Inspection) technology in API 581 is one of standard management technique for evaluating risk on petroleum plants. There are qualitative and quantitative assessments in RBI methodology. Quantitative evaluation step is complex and required much information, so high-risk facilities in plant are selected firstly by qualitative method. Qualitative RBI is performed by choosing the answer in prepared questionnaire. However, it is difficult to believe thoroughly results from survey including ambiguous information. In this study, the procedure of qualitative RBI analysis with considering probability distribution concept were proposed by using Monte Carlo simulation method in order to increase reliability in spite of uncertain factors. In addition, qualitative risk of cooling system for LNG plant was evaluated using proposed procedure. Although 20 items of total 39 assessment items are applied to uncertain factors, risk section of high probability(89%) were verified. The detailed results were described in manuscript.

Analysis of Sound Characteristics from Window Motors for Vehicle (차량용 창문 모터의 소음 특성 분석)

  • Kim, Jae-Won;Seo, Jin-Won;Lee, Kwang-Hee
    • 한국전산유체공학회:학술대회논문집
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    • 2008.03b
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    • pp.17-20
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    • 2008
  • An Electric motor is used for user-friendly equipment in vehicles. In this paper, an electric motor for windows is considered for the tunning of engineering inspection concerned with noise level from it. Noise from the electric window motor is a kind of structure-borne noise and becomes a reference parameter for its engineering performance. Estimation of noise from the motors shows the quantitative values such as overall noise. Noise level at each frequency and the qualitative figures for the transient characteristics of sound are also revealed. The loudness level, one of the qualitative parameters, distinguishes the performances of every components by the comparison of its magnitude. In summary, it is found that the qualitative comparisons become useful means for the inspection of electric motors.

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Development of Vehicle Sealing Inspection System Using Geometry Matching Method (형상 매칭법을 이용한 비이클 실링 검사 시스템 개발)

  • Lee, Jung-Ho;Park, Chan-Hee;Seo, Young-Soo;Lee, Hyung-Soo;Kim, Han-Joo
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.22 no.1
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    • pp.150-155
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    • 2013
  • This work present a new method of sealing inspection system for vehicle in which foam rubber materials are used for sealing the vehicle parts. This system is composed from a devices comprising non-contact and real-time scanning on visual inspection in machine parts. We have been investigated qualitative factors that influenced on sealing system of vehicle structure which flexibly attenuated vibration and plenty of foam rubber materials having elastic property. However, there are different factors which still depended on outdated technique (personnel subjective judgment) in the performance inspection of rubber parts, specially for cross section inspection. Through a newly developed inspection system which recently applied for the production line, we successfully achieved more effective results of matching rate by about 80 % in the sealing performance inspection with 0.7% to 1.4% in the repeated errors. These are resulted from non-contacted response by CCD camera and vision program using geometry matching method. We expect that this system may be widely applied in the strict inspection parts of more diverse cross-section in future.

A Study on the Safety Enhancement of Chemical Plants Using Risk Based Inspection Method (Risk Based Inspection 기법을 이용한 화학공장의 안전성 향상에 관한 연구)

  • 노용해;유진환;서재민;임차순;고재욱
    • Journal of the Korean Society of Safety
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    • v.17 no.3
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    • pp.73-80
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    • 2002
  • The RBI technique proposed by API is composed of three steps. The qualitative RBI method can be used for the purpose of screening the components with high risk. And the quantitative RBI method employs complex risk evaluation model for predicting component risk in a quantitative manner. The inspection program can be optimized based on the results obtained by these RBI technique. The forementioned RBI technique has been applied to a common hydrodesulfurizer unit and the technique is critically evaluated for studying its benefits and limitations, which is the main issue of this thesis. It's conducted that the RBI method can provide a method for defining and measuring the component risk, and also provide a powerful tool for managing many of the important elements of a process plant.

The Design & Manufacture of Multi-coil Eddy Current Sensor and Characteristic Analysis (다중코일 와전류 센서 설계제작 및 특성분석)

  • Ahn, Y.S.;Gil, D.S.;Park, S.G.
    • Journal of Power System Engineering
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    • v.15 no.3
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    • pp.65-69
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    • 2011
  • This paper introduces the multi-coil eddy current sensor and its characteristic in magnetic material gas turbine rotor. In the past, magnetic particle inspection method was used for qualitative defect evaluation in magnetic material gas turbine rotor. And the ultrasonic inspection method was used for quantitative defect evaluation. Nowadays, eddy current method is used in magnetic gas turbine rotor inspection due to advanced sensor design technology. We developed multi-coil eddy current sensor for the rotor dovetail inspection. At first, rotor stress is analyzed for the determination of sensor position and number. The sensor coils are designed to cover the stress concentration area of rotor dovetail. We select optimum frequency according to material standard penetration data and experiment results. The rotor mock-up and artificial defects were made for the signal detection and resolution analysis of multi-coil eddy current sensor. The results show that signal detection and resolution capabilities are enhanced in comparison to the commercialized sensor enough for the gas turbine rotor inspection. So, this developed multi-coil eddy current sensor substituted for commercialized one and it applied in real gas turbine rotor inspection.

Usefulness estimating of Time of flight(TOF) during Carotid angio inspection including Aortic arch (Aortic arch를 포함한 Carotid angio 검사 시 Time of flight(TOF)의 유용성 평가)

  • Yoo, Yeong-Jun
    • Korean Journal of Digital Imaging in Medicine
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    • v.15 no.1
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    • pp.1-7
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    • 2013
  • Purpose : The Carotid Angio inspection including Aortic arch applied to wide area is conducted as the Contrast Enhance MR Angiography(CEA) which is using a contrast medium. However it is a burden not only for someone such as infants, pregnant women and patients suffering from kidney failure but continuous use of contrast medium also can be a burden for patients who has been taken follow up inspection since diagnose lesion already. The purpose of this study is to estimate a usefulness of the Time of Flight (TOF) by comparing with CEA. Materials and methods : 10 patients with an average age of 58 (from 45 to 75) who had MRA inspection in our hospital were studied using 3.0 Tesla Aachieva (Philips, Netherland) MRI system and Sense Neuro-Vascular 16 Channels Coil. The same patient was inspected both TOF and CEA simultaneously. The TOF inspection included from Aortic arch to Willis Circle by connecting 3 TOF stacks and so did CEA inspection. The quantitative analysis was conducted through signal to noise ratio(SNR) and contrast to noise ratio(CNR) with soft tissue by setting up an area of interest on CCA bifurcatoin, ICA, ECA, MCA and VA concerning obtained image. In case of qualitative analysis, 3 radiological technologists and 1 radiologist evaluated 4 items (1: Visibility of the blood vessel, 2: Image distortion measure, 3: Overlapping measure with vein, 4: Peripheral blood vessel description measure) into five points scale (1: Very bad, 2: Bad, 3: Normal 4: Good, 5: Very good). Results : Results for the quantitative analysis was obtained by calculating the average of 5 ROIs in case of SNR and CNR separately. Results of SNR, TOF were generally measured higher than CEA (In case of TOF were 166.1, 205.2, 154.39, 172.23, 161.95, and CEA were 92.05, 95.43, 84.76, 73.69, 88.3). But according to the result of CNR, both TOF and CEA were measured similarly as 67.62, 106.71, 55.9, 73.74, 63.46 for TOF and 67.82, 71.19, 60.52, 49.45, 64.07 for CEA. Throughout every results of each ROI, SNR showed statistically meaningful consequence (0.050.05). In case of qualitative analysis the average of each evaluated item was 4.2points and 4.28points in the item1, 2.93points and 4.55points in the item2, 4.6points and 3.13points in the item3, 2.88points and 4.6points in the item4. According to the results TOF was measured higher in the item3 while in the item2 and item4 CEA was higher and in case of the item1, both CEA and TOF were similar. To sum up statistically meaningful results (p<0.05) were shown in the item2, item3 and item4 but not in the item1 (p>0.05). Conclusions : Both TOF and CEA are complementary because each inspection has pros and cons, but when inspect wide area including Aortic arch normally CEA is conducted. But TOF inspection also can be considered as alternative in terms of patients who has difficulty in the contrast medium such as infants, pregnant women and patients suffering from kidney failure and patients during follow up.

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Development of a machine vision system for automotive part car seat frame inspection (자동차 부품 카시트 프레임 검사를 위한 머신비전 개발)

  • Andres, Nelson S.;Jang, Bong-Choon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.4
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    • pp.1559-1564
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    • 2011
  • This study presents the development of a machine vision inspection system(MVIS) purposely for car seat frames as an alternative for human inspection. The proposed MVIS is designed to meet the demands, features and specifications of car seat frame manufacturing companies in striving for increased throughput of better quality. This computer-based MVIS is designed to perform quality measures by detecting holes, nuts and welding spots on every car seat frame in real time. In this study, the NI Vision Builder software for Automatic Inspection was used as a solution in configuring the aimed quality measurements. The techniques for visual inspection are optimized through qualitative analysis and simulation of human tolerance on inspecting car seat frames. Furthermore, this study exemplifies the incorporation of the optimized vision inspection environment to the pre-inspection and post-inspection subsystems. The system built on this proposed MVIS for car seat frames has successfully found the possible detections.

Development of a RBI Procedure and Implementation of a Software Based on API Code (I) - Qualitative Approach (API기준에 근거한 RBI 절차 개발 및 소프트웨어의 구현 (I) 정성적 접근법)

  • 심상훈;송정수;김지윤;윤기봉
    • Journal of the Korean Society of Safety
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    • v.17 no.3
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    • pp.66-72
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    • 2002
  • During the last ten years, effort has been made for reducing maintenance cost for aged equipments and ensuring safety, efficiency and profitability of petrochemical and refinery plants. Hence, it was required to develop advanced methods which meet this need. RBI(Risk Based Inspection) methodology is one of the most promising technology satisfying the requirements in the field of integrity management. In this study, a qualitative assessment algorithm for RBI based on the API 581 code was reconstructed for developing an RBI software. The user-friendly realRBI software is developed with a module for evaluating qualitative risk category using the potential consequence factor and the likelihood factor.

An Experimental Analysis on Dark-field Laser Scattering for the Surface Inspection of Infrared Cut-off Filters (적외선차단필터의 표면 검사를 위한 암시야 레이저산란에 대한 실험적 분석)

  • Kim, Gyung-Bum;Han, Jae-Chul
    • Journal of the Korean Society for Precision Engineering
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    • v.24 no.11
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    • pp.76-83
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    • 2007
  • The dark-field laser scattering system has been developed to inspect surface defects in infrared cut-off filters and then laser scattering characteristics against the defects are investigated. The qualitative analysis for the reliable and accurate detection performance is described through the correlation between incident angles of a laser and viewing ones of a camera. In this paper, reliable and important information with laser scattering is given for the surface defect inspection of IR filters. Its performance has been verified through various experiments.