No Cover Image

E-Thesis 284 views 120 downloads

An Examination of the Effectiveness of Proof Testing Regimes for Emergency Shutdown Valves / STEVEN KRIESCHER

Swansea University Author: STEVEN KRIESCHER

  • 2025_Kriescher_S.final.69880.pdf

    PDF | E-Thesis – open access

    Copyright: The author, Steven Ashwell Kriescher, 2025 Distributed under the terms of a Creative Commons Attribution 4.0 License (CC BY 4.0)

    Download (52.31MB)

DOI (Published version): 10.23889/SUThesis.69880

Abstract

The emergency shutdown valve is a critical element of a typical safety instrumented function. Consequently, both effective proof testing and an appropriate test interval are imperative to ensure the desired functionality, and hence a reliably safe operation of a high-hazard process facility.This rese...

Full description

Published: Swansea University, Wales, UK 2025
Institution: Swansea University
Degree level: Doctoral
Degree name: Ph.D
Supervisor: Thomas, R. A., and Phillips, C. O.
URI: https://cronfa.swan.ac.uk/Record/cronfa69880
first_indexed 2025-07-03T12:06:49Z
last_indexed 2025-07-04T06:42:54Z
id cronfa69880
recordtype RisThesis
fullrecord <?xml version="1.0"?><rfc1807><datestamp>2025-07-03T13:26:49.5349477</datestamp><bib-version>v2</bib-version><id>69880</id><entry>2025-07-03</entry><title>An Examination of the Effectiveness of Proof Testing Regimes for Emergency Shutdown Valves</title><swanseaauthors><author><sid>efc9e68ff200735e140c15f5622ce6d7</sid><firstname>STEVEN</firstname><surname>KRIESCHER</surname><name>STEVEN KRIESCHER</name><active>true</active><ethesisStudent>false</ethesisStudent></author></swanseaauthors><date>2025-07-03</date><abstract>The emergency shutdown valve is a critical element of a typical safety instrumented function. Consequently, both e&#xFB00;ective proof testing and an appropriate test interval are imperative to ensure the desired functionality, and hence a reliably safe operation of a high-hazard process facility.This research investigates the application of a Fuzzy Inference System (FIS) to model data uncertainty in Failure Modes, E&#xFB00;ects, and Diagnostic Analysis (FMEDA) for safety-critical systems. The research aims to address the limitations of traditional FMEDA methods in managing subjective expert data. A novel FIS-based framework was developed that employs trapezoidal membership functions to encode expert knowledge and analyse proof test coverage. Validation was performed using both real and synthetic datasets, achieving strong regression and low error metrics, with an overall R2 value of 0.96 and RMSE of 7, thus con&#xFB01;rming the accuracy of the model.The variation in proof test coverage predictions between the FMEDA and FIS methods was observed to be up to 3% for a full stroke test and up to 22% for a partial stroke test. A comparison of the FMEDA and FIS proof test coverage results suggests that the FIS approach supports further optimisation of emergency shutdown valve maintenance by integrating full and partial proof tests, extending proof test intervals, and enhancing plant uptime without compromising safety. The FIS results indicate a 100%improvement in both test intervals, which could extend the typical partial stroke test interval from six months to one year and the usual full stroke test interval from one year to two years.This work demonstrates that fuzzy inference systems can be employed to overcome issues relating to FMEDA data subjectivity allowing emergency shutdown valve proof test coverage estimates to be determined for both full and partial stroke tests. This re-search contributes to the integration of expert judgement in safety-related assessments, laying the foundation for future studies to validate and re&#xFB01;ne the model further.</abstract><type>E-Thesis</type><journal/><volume/><journalNumber/><paginationStart/><paginationEnd/><publisher/><placeOfPublication>Swansea University, Wales, UK</placeOfPublication><isbnPrint/><isbnElectronic/><issnPrint/><issnElectronic/><keywords>Functional safety, SIS, Emergency shutdown valves, proof test coverage, FMEDA, fuzzy inference systems</keywords><publishedDay>24</publishedDay><publishedMonth>4</publishedMonth><publishedYear>2025</publishedYear><publishedDate>2025-04-24</publishedDate><doi>10.23889/SUThesis.69880</doi><url/><notes>A selection of content is redacted or is partially redacted from this thesis to protect sensitive and personal information.</notes><college>COLLEGE NANME</college><CollegeCode>COLLEGE CODE</CollegeCode><institution>Swansea University</institution><supervisor>Thomas, R. A., and Phillips, C. O.</supervisor><degreelevel>Doctoral</degreelevel><degreename>Ph.D</degreename><apcterm/><funders/><projectreference/><lastEdited>2025-07-03T13:26:49.5349477</lastEdited><Created>2025-07-03T12:51:55.1597495</Created><path><level id="1">Faculty of Science and Engineering</level><level id="2">School of Engineering and Applied Sciences - Chemical Engineering</level></path><authors><author><firstname>STEVEN</firstname><surname>KRIESCHER</surname><order>1</order></author></authors><documents><document><filename>69880__34659__8d1e7d81e6ab4104bbd4350ca5d8e443.pdf</filename><originalFilename>2025_Kriescher_S.final.69880.pdf</originalFilename><uploaded>2025-07-03T13:05:05.1283951</uploaded><type>Output</type><contentLength>54846722</contentLength><contentType>application/pdf</contentType><version>E-Thesis &#x2013; open access</version><cronfaStatus>true</cronfaStatus><documentNotes>Copyright: The author, Steven Ashwell Kriescher, 2025 Distributed under the terms of a Creative Commons Attribution 4.0 License (CC BY 4.0)</documentNotes><copyrightCorrect>true</copyrightCorrect><language>eng</language><licence>https://creativecommons.org/licenses/by/4.0/</licence></document></documents><OutputDurs/></rfc1807>
spelling 2025-07-03T13:26:49.5349477 v2 69880 2025-07-03 An Examination of the Effectiveness of Proof Testing Regimes for Emergency Shutdown Valves efc9e68ff200735e140c15f5622ce6d7 STEVEN KRIESCHER STEVEN KRIESCHER true false 2025-07-03 The emergency shutdown valve is a critical element of a typical safety instrumented function. Consequently, both effective proof testing and an appropriate test interval are imperative to ensure the desired functionality, and hence a reliably safe operation of a high-hazard process facility.This research investigates the application of a Fuzzy Inference System (FIS) to model data uncertainty in Failure Modes, Effects, and Diagnostic Analysis (FMEDA) for safety-critical systems. The research aims to address the limitations of traditional FMEDA methods in managing subjective expert data. A novel FIS-based framework was developed that employs trapezoidal membership functions to encode expert knowledge and analyse proof test coverage. Validation was performed using both real and synthetic datasets, achieving strong regression and low error metrics, with an overall R2 value of 0.96 and RMSE of 7, thus confirming the accuracy of the model.The variation in proof test coverage predictions between the FMEDA and FIS methods was observed to be up to 3% for a full stroke test and up to 22% for a partial stroke test. A comparison of the FMEDA and FIS proof test coverage results suggests that the FIS approach supports further optimisation of emergency shutdown valve maintenance by integrating full and partial proof tests, extending proof test intervals, and enhancing plant uptime without compromising safety. The FIS results indicate a 100%improvement in both test intervals, which could extend the typical partial stroke test interval from six months to one year and the usual full stroke test interval from one year to two years.This work demonstrates that fuzzy inference systems can be employed to overcome issues relating to FMEDA data subjectivity allowing emergency shutdown valve proof test coverage estimates to be determined for both full and partial stroke tests. This re-search contributes to the integration of expert judgement in safety-related assessments, laying the foundation for future studies to validate and refine the model further. E-Thesis Swansea University, Wales, UK Functional safety, SIS, Emergency shutdown valves, proof test coverage, FMEDA, fuzzy inference systems 24 4 2025 2025-04-24 10.23889/SUThesis.69880 A selection of content is redacted or is partially redacted from this thesis to protect sensitive and personal information. COLLEGE NANME COLLEGE CODE Swansea University Thomas, R. A., and Phillips, C. O. Doctoral Ph.D 2025-07-03T13:26:49.5349477 2025-07-03T12:51:55.1597495 Faculty of Science and Engineering School of Engineering and Applied Sciences - Chemical Engineering STEVEN KRIESCHER 1 69880__34659__8d1e7d81e6ab4104bbd4350ca5d8e443.pdf 2025_Kriescher_S.final.69880.pdf 2025-07-03T13:05:05.1283951 Output 54846722 application/pdf E-Thesis – open access true Copyright: The author, Steven Ashwell Kriescher, 2025 Distributed under the terms of a Creative Commons Attribution 4.0 License (CC BY 4.0) true eng https://creativecommons.org/licenses/by/4.0/
title An Examination of the Effectiveness of Proof Testing Regimes for Emergency Shutdown Valves
spellingShingle An Examination of the Effectiveness of Proof Testing Regimes for Emergency Shutdown Valves
STEVEN KRIESCHER
title_short An Examination of the Effectiveness of Proof Testing Regimes for Emergency Shutdown Valves
title_full An Examination of the Effectiveness of Proof Testing Regimes for Emergency Shutdown Valves
title_fullStr An Examination of the Effectiveness of Proof Testing Regimes for Emergency Shutdown Valves
title_full_unstemmed An Examination of the Effectiveness of Proof Testing Regimes for Emergency Shutdown Valves
title_sort An Examination of the Effectiveness of Proof Testing Regimes for Emergency Shutdown Valves
author_id_str_mv efc9e68ff200735e140c15f5622ce6d7
author_id_fullname_str_mv efc9e68ff200735e140c15f5622ce6d7_***_STEVEN KRIESCHER
author STEVEN KRIESCHER
author2 STEVEN KRIESCHER
format E-Thesis
publishDate 2025
institution Swansea University
doi_str_mv 10.23889/SUThesis.69880
college_str Faculty of Science and Engineering
hierarchytype
hierarchy_top_id facultyofscienceandengineering
hierarchy_top_title Faculty of Science and Engineering
hierarchy_parent_id facultyofscienceandengineering
hierarchy_parent_title Faculty of Science and Engineering
department_str School of Engineering and Applied Sciences - Chemical Engineering{{{_:::_}}}Faculty of Science and Engineering{{{_:::_}}}School of Engineering and Applied Sciences - Chemical Engineering
document_store_str 1
active_str 0
description The emergency shutdown valve is a critical element of a typical safety instrumented function. Consequently, both effective proof testing and an appropriate test interval are imperative to ensure the desired functionality, and hence a reliably safe operation of a high-hazard process facility.This research investigates the application of a Fuzzy Inference System (FIS) to model data uncertainty in Failure Modes, Effects, and Diagnostic Analysis (FMEDA) for safety-critical systems. The research aims to address the limitations of traditional FMEDA methods in managing subjective expert data. A novel FIS-based framework was developed that employs trapezoidal membership functions to encode expert knowledge and analyse proof test coverage. Validation was performed using both real and synthetic datasets, achieving strong regression and low error metrics, with an overall R2 value of 0.96 and RMSE of 7, thus confirming the accuracy of the model.The variation in proof test coverage predictions between the FMEDA and FIS methods was observed to be up to 3% for a full stroke test and up to 22% for a partial stroke test. A comparison of the FMEDA and FIS proof test coverage results suggests that the FIS approach supports further optimisation of emergency shutdown valve maintenance by integrating full and partial proof tests, extending proof test intervals, and enhancing plant uptime without compromising safety. The FIS results indicate a 100%improvement in both test intervals, which could extend the typical partial stroke test interval from six months to one year and the usual full stroke test interval from one year to two years.This work demonstrates that fuzzy inference systems can be employed to overcome issues relating to FMEDA data subjectivity allowing emergency shutdown valve proof test coverage estimates to be determined for both full and partial stroke tests. This re-search contributes to the integration of expert judgement in safety-related assessments, laying the foundation for future studies to validate and refine the model further.
published_date 2025-04-24T06:48:08Z
_version_ 1851284089682788352
score 11.089469

Similar Items