Projects
Projects: Projects for Investigator |
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| Reference Number | NIA_SGN0140 | |
| Title | Derivation of a Risk Based Approach to High Pressure Filter & Pig Trap Closure Inspection Frequencies | |
| Status | Completed | |
| Energy Categories | Other Cross-Cutting Technologies or Research 50%; Fossil Fuels: Oil Gas and Coal(Oil and Gas, Refining, transport and storage of oil and gas) 50%; |
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| Research Types | Applied Research and Development 100% | |
| Science and Technology Fields | ENGINEERING AND TECHNOLOGY (Mechanical, Aeronautical and Manufacturing Engineering) 100% | |
| UKERC Cross Cutting Characterisation | Not Cross-cutting 100% | |
| Principal Investigator |
Project Contact No email address given SGN |
|
| Award Type | Network Innovation Allowance | |
| Funding Source | Ofgem | |
| Start Date | 01 January 2019 | |
| End Date | 01 March 2021 | |
| Duration | ENA months | |
| Total Grant Value | £781,397 | |
| Industrial Sectors | Energy | |
| Region | South East | |
| Programme | Network Innovation Allowance | |
| Investigators | Principal Investigator | Project Contact , SGN (99.996%) |
| Other Investigator | Project Contact , Wales and West Utilities (0.001%) Project Contact , National Grid Gas Transmission (0.001%) Project Contact , Northern Gas Networks (0.001%) Project Contact , Cadent Gas (0.001%) Project Contact , SGN (99.996%) |
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| Industrial Collaborator | Project Contact , SGN (0.000%) |
|
| Web Site | https://smarter.energynetworks.org/projects/NIA_SGN0140 |
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| Objectives | Development of a new tool, effectively a live examination specification which will allow Users to update their WSoEs to reflect the revised Examination Dates which would consider past and future anticipated operational duty. Development of a risk based inspection regime for cast steel filter bodies and cast steel pig trap closures. The main risk contributor being considered will be fatigue crack growth. Development of less conservative allowable defect sizes. Development of less conservative grind repair limits The work proposed below will be undertaken in 5 stages.1) Data collection, interpretation & industry search Networks & NG. 2) Analytical (Defect Limits).3)Validation Testing (Fatigue testing, Burst Testing, Metallography).4) Development of tool to allow updating of WSoEs.5)Detailed final report The objective of the scope of work are; Development of a risk based inspection regime for cast steel filter bodies and cast steel pig trap closures. The main risk contributor being considered will be fatigue crack growth. Development of less conservative allowable defect sizes. Development of less conservative grind repair limits Development of a new tool, effectively a live examination specification which will allow Users to update their WSoEs to reflect the revised Examination Dates which would consider past and future anticipated operational duty. | |
| Abstract | Since the inception and introduction of the pressure systems safety regulations in 1999 the UK gas networks have inspected their filter population and pig trap population on fixed time periods of 6 and 12 yearly intervals for visual and MPI respectively in accordance with the current Written Scheme of Examination (WSoE). During this period the Networks are not aware of a single instance of a loss of containment caused through corrosion or fatigue crack growth on either asset type.The majority of the filter population are manufactured from cast steel. The pig traps closures which are considered to be a critical component of the pig trap vessels are, historically, also manufactured from cast steel. It is worth noting though that in recent years there has been a move to the band-lock closure which is manufactured from forged material.When inspections are undertaken defects are frequently identified in the cast steel materials. Defects found then must be assessed to determine if they are within each operators allowable defect size limits. If they are not within safe operating limits a number of options are available to the Networks, typically: Increased monitoring Grinding repair Weld repair Replacement Hydrotest revalidation These options can be very expensive to implement in terms of cost, time and HSE implications. Due to the nature of the pressure vessels, particularly those manufactured from cast steel, there is increasing suspicion that many of the defects found during inspection are original manufacturing defects. Unfortunately, without the initial inspection records, it is impossible to substantiate this suspicion, but the project will look to prove that the defects are stable i.e. not propagating or growing at an extremely slow rate. In addition, it is also believed that the allowable defect size limits and the allowable grinding limits are unnecessarily conservative. The implications of this are: Unnecessary inspections are being undertaken Unnecessary assessments are being undertaken Unnecessary remediation and replacements are being undertaken as a result of the above, significant additional costs are being incurred along with an additional unnecessary increase in HSE risk from additional driving and on-site activities. | |
| Publications | (none) |
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| Final Report | (none) |
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| Added to Database | 14/12/22 | |
