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Projects: Projects for Investigator
Reference Number	NIA_NGGT0033
Title	Hot Tap Buried Sample Probe
Status	Completed
Energy Categories	Fossil Fuels: Oil Gas and Coal(Oil and Gas, Refining, transport and storage of oil and gas) 100%;
Research Types	Applied Research and Development 100%
Science and Technology Fields	PHYSICAL SCIENCES AND MATHEMATICS (Metallurgy and Materials) 20%; ENGINEERING AND TECHNOLOGY (Civil Engineering) 40%; ENGINEERING AND TECHNOLOGY (Mechanical, Aeronautical and Manufacturing Engineering) 40%;
UKERC Cross Cutting Characterisation	Not Cross-cutting 100%
Principal Investigator	Project Contact No email address given National Grid Gas Transmission
Award Type	Network Innovation Allowance
Funding Source	Ofgem
Start Date	01 July 2013
End Date	01 January 2016
Duration	30 months
Total Grant Value	£610,000
Industrial Sectors	Technical Consultancy
Region	London
Programme	Network Innovation Allowance
Investigators	Principal Investigator	Project Contact , National Grid Gas Transmission (100.000%)
Web Site	http://www.smarternetworks.org/project/NIA_NGGT0033
Objectives	The project aims to deliver successfully a field demonstration of a combination of three new probe designs and construction techniques. The installation of new low volume sample probes incorporating the improved design solution at the trial site.
Abstract	New gas analysers are being installed across the National Transmission System (NTS) to replace obsolete analysers and improve the accuracy of the calorific value (CV) sample value calculation. These analysers require more efficient sample systems that require smaller vented gas volumes, and significantly improved analyser response times. In order to meet this requirement new low volume gas sample probes are being installed. However, traditionally the existing gas sample points within the NTS are installed with plug valves or small isolation points but these are unable to accommodate the new low volume probes, because they require a 2" full bore Ball valve clearance with Double Block and Bleed isolation. This necessitates installations with above ground platforms and below ground access to meet maintenance and replacement requirements. This project looks to trial an alternative design to eliminate the need for working at heights and within confined spaces and which will therefore reduce maintenance costs and reduce human factor risk. Feasibility Stage Site investigation to include trial holes, scrapings and definition of hot tap location. Liaison with manufacturers and suppliers to further develop the concept. Development and detailing of the concept of the calorific value sample points (CVSPs) arrangement installation in a report format, to include outline arrangement drawings, Process Flow Diagrams (PFDs) and 3D isometric views. Conceptual Stage Develop and include a Best Available Technology (BAT) assessment. Design of CVSP’s installation to: Develop and include reliability assessments. Include a generic HAZOP study to address process safety requirements fully in accordance with T/SP/HAZ/7. Challenge and Review meeting with appropriate stakeholders. Design package and appraisal in accordance with T/SP/G/35. Delivery Phase To include material procurement and non-routine operation compilation. Mechanical & Civil works delivery to include mobilisation site works - Necessary restrictions obligated by National Grid System Operations on carrying out Hot Work during the winter period resulted in significant delays. Approval has now been given to commence the Hot Work within a working environment, from April 2014. VE technology probe installation to include lifting works and commissioning. Details of Change to Project Delivery: As described above the project was in three phases, Feasibility, Conceptual design and Implementation phases. There have been issues requiring additional work in all three phases as detailed below;-Feasibility The feasibility study phase included excavating pilot holes and taking material samples (scrapings) to identify suitable sections of the below ground pipe-work for the installation of the Hot Tap connections. The team had begun the main works phase when it discovered that in certain locations the pipe geometry was non-standard: the pipe weld seam was at 12:00 o’clock position for extended distance. When the trial holes were dug, the team were concentrating on pipe depth so valve stems could be ordered and did the scrapings to enable welding procedures to be produced. The location of the seam weld was not initially identified. Unfortunately, this meant the civil team was geared up to do the main job not just the trial hole and hence the larger contractor costs incurred. They were able to complete 3 of the 4 hot taps but 1 couldn’t be done. It is not possible to hot tap onto a weld, initially this led to the requirement for larger excavations and extended site time and re-visits for main civil works contractor. However it was established that on the trial site this nonstandard pipe geometry extended outside the site boundary triggering a requirement for a modified design. These factors have resulted in a cost increase and extension to the allowed time for this phase. Conceptual As a result of the issues identified (pipe geometry) in the feasibility section, a revised design was approved which involved a welded split Tee with an offset vertical connection. This resulted in a cost increase and extension to the allowed time for this phase. Delivery The implementation at Churchover Tee F2 Hot Tap connection will now have to include exploration of design options with manufacturers, designers and PMC, a further G35 approved design, additional components (Split Tee and Offset mounted valve/Probe) and will require are mobilization to site of the Hot Tap and civils teams with a projected completion of this work by 30th June 2015.Note : Project Documents may be available via the ENA Smarter Networks Portal using the Website link above
Publications	(none)
Final Report	(none)
Added to Database	20/08/18