An Update to the Recommended UKOPA External Interference Frequency Prediction Model and Pipeline Damage Distributions

2018 ◽  
Author(s):  
Graham Goodfellow ◽  
Chris Lyons ◽  
Susannah Turner ◽  
Fraser Gray ◽  
Simon Joyce
Keyword(s):  
Failure Rate ◽  
Structural Reliability ◽  
Operating Experience ◽  
External Interference ◽  
Failure Frequency ◽  
Depth Analysis ◽  
Product Loss ◽  
Distribution Parameters ◽  
The Uk ◽  
Incident Rates

The United Kingdom Onshore Pipeline Operators Association (UKOPA) was formed by UK pipeline operators to provide a common forum for representing operators interests in the safe management of pipelines. This includes providing historical failure statistics for use in pipeline quantitative risk assessment and UKOPA maintain a database to record this data. The UKOPA database holds data on product loss failures of UK major accident hazard pipelines from 1962 onwards and currently has a total length of 21,845 km of pipelines reporting. Overall exposure from 1952 to 2016 is 927,351 km years of operating experience with a total of 197 product loss incidents since 1962. The low number of failures means that the historical failure rate for pipelines of some specific diameters, wall thicknesses and material grades is zero or statistically insignificant. It is unreasonable to assume that the failure rate for these pipelines is actually zero. In addition to product loss incidents, the UKOPA database contains extensive data on measured part wall damage that did not cause product loss, unlike the European Gas Incident data Group (EGIG) database, which also includes the UK gas transmission pipeline product loss data. The data on damage to pipelines caused by external interference can be assessed to derive statistical distribution parameters describing the expected gouge and dent dimensions resulting from an incident. Overall external interference incident rates for different class locations can also be determined. These distributions and incident rates can be used in structural reliability based techniques to predict the failure frequency due to external interference for a given set of pipeline parameters. The current distributions of external interference damage were derived from data up to 2009 and presented as Weibull distributions for gouge depth, gouge length and dent depth. Analysis undertaken for the COOLTRANS CO2 pipeline project, undertaken by National Grid in the UK, has identified several improvements to the recommended UKOPA approach to external interference failure frequency prediction. This paper summarises those improvements and presents updated damage distribution parameters from data up to 2016.

An Update to the UKOPA Pipeline Damage Distributions

2012 ◽  
Author(s):  
Graham Goodfellow ◽  
Susannah Turner ◽  
Jane Haswell ◽  
Richard Espiner
Keyword(s):  
Failure Rate ◽  
Structural Reliability ◽  
Operating Experience ◽  
Quantitative Risk Assessment ◽  
External Interference ◽  
Failure Frequency ◽  
Product Loss ◽  
Distribution Parameters ◽  
Transmission Pipeline ◽  
Incident Rates

The United Kingdom Onshore Pipeline Operators Association (UKOPA) was formed by UK pipeline operators to provide a common forum for representing operators interests in the safe management of pipelines. This includes providing historical failure statistics for use in pipeline quantitative risk assessment and UKOPA maintain a database to record this data. The UKOPA database holds data on product loss failures of UK major accident hazard pipelines from 1962 onwards and currently has a total length of 22,370 km of pipelines reporting. Overall exposure from 1952 to 2010 is of over 785,000 km years of operating experience with a total of 184 product loss incidents during this period. The low number of failures means that the historical failure rate for pipelines of some specific diameters, wall thicknesses and material grades is zero or statistically insignificant. It is unreasonable to assume that the failure rate for these pipelines is actually zero. However, unlike the European Gas Incident data Group (EGIG) database, which also includes the UK gas transmission pipeline data, the UKOPA database contains extensive data on measured part wall damage that did not cause product loss. The data on damage to pipelines caused by external interference can be assessed to derive statistical distribution parameters describing the expected gouge length, gouge depth and dent depth resulting from an incident. Overall 3rd party interference incident rates for different class locations can also be determined. These distributions and incident rates can be used in structural reliability based techniques to predict the failure frequency due to 3rd party damage for a given set of pipeline parameters. The UKOPA recommended methodology for the assessment of pipeline failure frequency due to 3rd party damage is implemented in the FFREQ software. The distributions of 3rd party damage currently used in FFREQ date from the mid-1990s. This paper describes the work involved in updating the analysis of the damage database and presents the updated distribution parameters. A comparison of predictions using the old and new distributions is also presented.

A Methodology for the Prediction of Pipeline Failure Frequency Due to External Interference

2008 ◽  
Author(s):  
C. Lyons ◽  
J. V. Haswell ◽  
P. Hopkins ◽  
R. Ellis ◽  
N. Jackson
Keyword(s):  
Damage Mechanism ◽  
External Interference ◽  
Gas Industry ◽  
Failure Frequency ◽  
Failure Data ◽  
Mechanics Model ◽  
The United Kingdom ◽  
Pipeline Failure ◽  
The Uk ◽  
Operational Failure

The United Kingdom Onshore Pipeline Operators Association (UKOPA) is developing supplements to the UK pipeline codes BSI PD 8010 and IGE/TD/1. These supplements will provide a standardized approach for the application of quantified risk assessment to pipelines. UKOPA has evaluated and recommended a methodology: this paper covers the background to, and justification of, this methodology. The most relevant damage mechanism which results in pipeline failure is external interference. Interference produces a gouge, dent or a dent-gouge. This paper describes the fracture mechanics model used to predict the probability failure of pipelines containing dent and gouge damage and contains predictions of failure frequency obtained using the gas industry failure frequency prediction methodologies FFREQ and operational failure data from the UKOPA fault database. The failure model and prediction methodology are explained and typical results are presented and discussed.

Reduction Factors for Estimating the Probability of Failure of Mechanical Damage Due to External Interference

2008 ◽  
Author(s):  
Andrew Cosham ◽  
Jane Haswell ◽  
Neil Jackson
Keyword(s):  
Structural Reliability ◽  
Historical Data ◽  
Mechanical Damage ◽  
Probability Of Failure ◽  
Risk Assessments ◽  
External Interference ◽  
Failure Data ◽  
Major Accident ◽  
The Uk ◽  
Reduction Factors

Quantified risk assessments (QRAs) are widely used in the UK to assess the significance of the risk posed by major accident hazard pipelines on the population and infrastructure in the vicinity of the pipeline. A QRA requires the calculation of the frequency of failures and the consequences of failures. One of the main causes of failures in onshore pipelines is mechanical damage due to external interference, such as a dent, a gouge, or a dent and gouge. In the published literature, two methods have been used to calculate the probability of failure due to external interference: • historical failure data and • limit state functions combined with historical data (i.e. structural reliability-based methods). Structural reliability-based methods are mathematically complicated, compared to using historical failure data, but have several advantages, e.g. extrapolation beyond the limited historical data, and the identification of trends that may not be apparent in the historical data. In view of this complexity, proposed supplements to the UK pipeline design codes IGE/TD/1 (natural gas) and PD 8010 (all substances) — on the application of QRAs to proposed developments in the vicinity of major accident hazard pipelines — include simple ‘reduction factors’ for use in ‘screening’ risk assessments. These ‘reduction factors’ are based on a comprehensive parametric study using a structural reliability-based model to calculate the probability of failure due to mechanical damage, defined as: gouges, and dents and gouges. The two ‘reduction factors’ are expressed in terms of the design factor and wall thickness of the pipeline. It is shown that, through appropriate normalisation, the effects of diameter, grade and toughness are secondary. Reasonably accurate, but conservative, estimates of the probability of failure can be obtained using these ‘reduction factors’. The proposed methodology is considerably simpler than a structural reliability-based analysis. The development and verification of these ‘reduction factors’ is described in this paper.

Revision to the UK Pipeline Quantitative Risk Assessment Guidelines IGEM/TD/2 and PD 8010-3

2014 ◽  
Author(s):  
Graham D. Goodfellow ◽  
Jane V. Haswell ◽  
Neil W. Jackson ◽  
Roger Ellis
Keyword(s):  
Risk Assessment ◽  
Land Use ◽  
Land Use Planning ◽  
Best Practice ◽  
Research Work ◽  
Quantitative Risk Assessment ◽  
External Interference ◽  
Common View ◽  
Failure Frequency ◽  
The Uk

The United Kingdom Onshore Pipeline Operators Association (UKOPA) was formed by UK pipeline operators to provide a common forum for representing pipeline operators interests in the safe management of pipelines. This includes ensuring that UK pipeline codes include best practice, and that there is a common view in terms of compliance with these codes. Quantitative risk assessment (QRA) is used by operators in the UK to determine if individual and societal risk levels at new developments adjacent to existing pipelines are as low as reasonably practicable (ALARP). In 2008 the UKOPA Risk Assessment Working Group developed codified advice on the use of QRA applied to land use planning assessments, which was published by the Institution of Gas Engineers & Managers (IGEM) and the British Standards Institute (BSI). This advice was designed to ensure a standard and consistent approach, and reduce the potential for disagreement between stakeholders on the acceptability of proposed developments. Since publication of IGEM/TD/2 and PD8010-3 in 2008, feedback from users of the guidance together with new research work and additional discussions with the UK safety regulator, the Health & Safety Executive (HSE), have been undertaken and the codified advice has been revised and reissued in June 2013. This paper describes the revisions to the guidance given in these codes in relation to: • Clarification on application • Update of physical risk mitigation measures (slabbing and depth of cover) • Update of HSE approach to Land Use Planning • Update of failure frequency data: ○ Weibull damage distributions for external interference ○ Generic failure frequency curve for external interference ○ Prediction of failure frequency due to landsliding The revised codes, and their content, are considered to represent the current UK best practice in pipeline QRA.

Development of the UKOPA Strategy for the Management of Ageing Pipelines

2016 ◽  
Author(s):  
Graham Goodfellow ◽  
Jane Haswell ◽  
Graeme Pailor ◽  
Peter Davis ◽  
Rod McConnell
Keyword(s):  
Good Practice ◽  
Ground Movement ◽  
External Interference ◽  
Frequency Model ◽  
Common View ◽  
Damage Data ◽  
Product Loss ◽  
Failure Models ◽  
The Uk ◽  
The Impact

The United Kingdom Onshore Pipeline Operators Association (UKOPA) was formed by UK pipeline operators in 1996 to provide a common forum for representing pipeline operators’ interests in the safe management of pipelines. This includes ensuring that UK pipeline codes include good practice, and that there is a common view in terms of compliance with these codes. To achieve this UKOPA has carried out a number of technical initiatives and studies to establish good practice requirements for UK operators which aim to ensure pipeline integrity is managed such that the risks posed by pipelines are as low as reasonably practicable (ALARP) in accordance with UK goal-setting safety legislation. UKOPA has developed Quantitative Risk Assessment (QRA) methodology which is published in UK standards and detailed guidance on the derivation of pipeline specific external interference failure frequencies, which have previously been published at IPC. The external interference frequency model is based on an analysis of data recorded in the UKOPA fault database which records product loss and damage data for UK major accident hazard pipelines from 1962 onwards. The database currently has a total length of 22,158 km of pipelines with over 877,598 km years of operating experience. The failure data is sparse, with only 192 product loss incidents, so where possible damage data and engineering failure models are used to develop reliable pipeline failure rates. To date this work has concentrated on the random failure causes of external interference and ground movement, which generate the major residual risk posed by pipelines in the UK. The majority of the UK pipeline population is now older than the original 40 years target design life. Consequently, the current UKOPA strategy is focused on the issues which affect the integrity and risk management of ageing pipelines. This requires the investigation of potential damage mechanisms which may affect older pipelines, including the impact of degradation of components which are no longer allowed by current standards, such as pipeline sleeves (casings), the degradation of damage which occurred during original construction and the assessment of the impact of material and weld quality standards typical of older pipelines. The work currently being undertaken by UKOPA involves first the assessment of the impact on integrity, then the development of engineering failure models, and finally the application of the models to the UK pipeline population to predict failure frequencies which are then compared with recorded data. This paper describes the assessment of the UKOPA damage data to identify indications of age related damage and deterioration trends, the development of practical integrity models for the assessment of pipeline sleeves and construction dents and the application of these models to the UK pipeline population. It also discusses an approach developed for UKOPA ethylene pipeline operators to assess population developments adjacent to existing pipelines.

Efficacy and safety data for the Ab interno XEN45 gel stent implant at 3 Years: A retrospective analysis

2021 ◽  
pp. 112067212110143
Author(s):  
Itay E Gabbay ◽  
Mordechai Goldberg ◽  
Felicity Allen ◽  
Zhiheng Lin ◽  
Christine Morley ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Failure Rate ◽  
Open Angle Glaucoma ◽  
Safety Data ◽  
Angle Closure ◽  
Efficacy And Safety ◽  
Antihypertensive Medications ◽  
Uk National Health Service ◽  
The Uk ◽  
Comparative Audit

Purpose: To report efficacy and safety measures of the XEN45 gel stent at 36 months in the UK National Health Service setting. Methods: Retrospective non-comparative audit of the records of patients who underwent XEN45 implantation between June 2015 and May 2017 was performed. Main outcome measures were intraocular pressure and number of antihypertensive medications used. Failure was defined as need for further surgery or stent removal. Success was defined as a 20% decrease in intraocular pressure without the need for additional glaucoma medications or a reduction in antihypertensive medications without an increase in baseline intraocular pressure. Needling rates and preoperative factors effect were assessed. Results: The cohort included 205 patients (205 eyes) with primary open angle glaucoma (84.4%), angle closure glaucoma (7.8%), or refractory glaucoma (7.8%), 62.9% had a stand-alone procedure and 37.1%, a combined phaco-XEN45 procedure. Mean intraocular pressure was 22.6 ± 7.0 mmHg at baseline compared to 14.7 ± 3.8 mmHg at 24 months and 14.0 ± 2.9 mmHg at 36 months ( p < 0.001 for both). Mean number of medications used was 2.6 ± 1.1 at baseline compared to 0.5 ± 0.9 and 0.6 ± 1.0, at 24- and 36-months, respectively ( p < 0.001 for both). The failure rate at 36 months was 25%. Needling was required in 36.6%. Evaluation of background factors yielded an increased failure rate in non-Caucasians compared to Caucasians (74% vs 21%, p < 0.001). Conclusion: XEN45 implantation is effective and safe at 36 months’ follow-up. Patients should be advised regarding the risk of failure and possible need for bleb revisions. Careful patient selection may be required.

scholarly journals Resituating the political in cultural intermediary work: Charity sector public relations and communication

2021 ◽  
pp. 136754942199423
Author(s):  
Anne M Cronin ◽  
Lee Edwards
Keyword(s):  
Public Relations ◽  
Power Relations ◽  
Party Politics ◽  
The Political ◽  
Depth Analysis ◽  
Cultural Intermediary ◽  
Cultural Intermediaries ◽  
The Uk ◽  
The Relationship

Drawing on a case study of public relations in the UK charity sector, this article argues that cultural intermediary research urgently requires a more sustained focus on politics and the political understood as power relations, party politics and political projects such as marketization and neoliberalism. While wide-ranging research has analysed how cultural intermediaries mediate the relationship between culture and economy, this has been at the expense of an in-depth analysis of the political. Using our case study as a prompt, we highlight the diversity of ways that the political impacts cultural intermediary work and that cultural intermediary work may impact the political. We reveal the tensions that underpin practice as a result of the interactions between culture, the economy and politics, and show that the tighter the engagement of cultural intermediation with the political sphere, the more tensions must be negotiated and the more compromised practitioners may feel.

scholarly journals Ectopic pregnancy: exploration of its global research architecture using density-equalising mapping and socioeconomic benchmarks

BMJ Open ◽  
2017 ◽  
Vol 7 (10) ◽  
pp. e018394 ◽  
Author(s):  
Dörthe Brüggmann ◽  
Jana Kollascheck ◽  
David Quarcoo ◽  
Michael H Bendels ◽  
Doris Klingelhöfer ◽  
...  
Keyword(s):  
Ectopic Pregnancy ◽  
Gdp Per Capita ◽  
Related Research ◽  
Depth Analysis ◽  
The Usa ◽  
Per Capita ◽  
The Uk ◽  
Research Architecture ◽  
Country Specific ◽  
Global Research

ObjectiveAbout 2% of all pregnancies are complicated by the implantation of the zygote outside the uterine cavity and termed ectopic pregnancy. Whereas a multitude of guidelines exists and related research is constantly growing, no thorough assessment of the global research architecture has been performed yet. Hence, we aim to assess the associated scientific activities in relation to geographical and chronological developments, existing research networks and socioeconomic parameters.DesignRetrospective, descriptive study.SettingOn the basis of the NewQIS platform, scientometric methods were combined with novel visualising techniques such as density-equalising mapping to assess the scientific output on ectopic pregnancy. Using the Web of Science, we identified all related entries from 1900 to 2012.Results8040 publications were analysed. The USA and the UK were dominating the field in regard to overall research activity (2612 and 723 publications), overall citation numbers and country-specific H-Indices (US: 80, UK: 42). Comparison to economic power of the most productive countries demonstrated that Israel invested more resources in ectopic pregnancy-related research than other nations (853.41 ectopic pregnancy-specific publications per 1000 billlion US$ gross domestic product (GDP)), followed by the UK (269.97). Relation to the GDP per capita index revealed 49.3 ectopic pregnancy-specific publications per US$1000 GDP per capita for the USA in contrast to 17.31 for the UK. Semiqualitative indices such as country-specific citation rates ranked Switzerland first (24.7 citations per ectopic pregnancy-specific publication), followed by the Scandinavian countries Finland and Sweden. Low-income countries did not exhibit significant research activities.ConclusionsThis is the first in-depth analysis of global ectopic pregnancy research since 1900. It offers unique insights into the global scientific landscape. Besides the USA and the UK, Scandinavian countries and Switzerland can also be regarded as leading nations with regard to their relative socioeconomic input.

scholarly journals Neglect Of Parameter Estimation Uncertainty Can Significantly Overestimate Structural Reliability

2015 ◽  
Vol 15 (2) ◽  
Author(s):  
Árpád Rózsás ◽  
Miroslav Sýkora
Keyword(s):  
Parameter Estimation ◽  
Bayesian Statistics ◽  
Failure Probability ◽  
Structural Reliability ◽  
Probabilistic Models ◽  
Estimation Uncertainty ◽  
Point Estimates ◽  
Distribution Parameters ◽  
Order Of Magnitude ◽  
Parameter Estimation Uncertainty

Abstract Parameter estimation uncertainty is often neglected in reliability studies, i.e. point estimates of distribution parameters are used for representative fractiles, and in probabilistic models. A numerical example examines the effect of this uncertainty on structural reliability using Bayesian statistics. The study reveals that the neglect of parameter estimation uncertainty might lead to an order of magnitude underestimation of failure probability.

Diabetes mellitus and the kidney

2010 ◽  
pp. 4021-4032
Author(s):  
Rudolf Bilous
Keyword(s):  
Renal Disease ◽  
United States Of America ◽  
The United States ◽  
Endstage Renal Disease ◽  
The United Kingdom ◽  
The Uk ◽  
Developed World ◽  
Incident Rates

Diabetic nephropathy is the commonest cause of endstage renal disease in the developed world, causing 44% of prevalent cases requiring renal replacement therapy in the United States of America in 2012 and 25% in the United Kingdom in 2013. Incident rates have increased slightly in the UK at 25% of all new patients accepted onto RRT in 2013. Most patients have type 2 diabetes, and in most countries the proportion with endstage renal disease who have type 1 diabetes is falling....

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