Projects

Projects: Projects for Investigator

Objectives:

The objectives of this feasibility study are to provide possible solutions to the scope, broken into the following sections:

• Access Fitting
• Access System
• In-pipe robotic platform
• Sealant Application System
• In-pipe CCTV
• External Support Systems

In addition, the study will assess whether there are feasible development solutions available globally that can meet the elements of the complete performance specification.

Expected Benefits: The success of this project will be determined against the quality and content of the technical feasibility study, as well as the project duration. The expected outcomes, representing successful project delivery, will be:

• A detailed report on the required developments of current technology available to be able to meet the scope listed above
• Assessment of the associated cost of developing the current technology available to meet the specification provided
• A cost comparison against current repair techniques
• An identified method of progressing the technology.

From the 1850’s up until the 1950’s cast iron mains were used extensively across the United Kingdom (UK) gas distribution network. Now the gas industry has moved away from this source of material and is using steel and polyethylene. However a significant portion of larger diameter cast iron is still in use today. At present across SGN there are approximately 843 kilometres of metallic mains >12" diameter that are ageing, requiring inspection, repair or replacement. When installed, these sections of mains were connected at the joint by a bell and spigot. To seal the joints, jute - a plant fibre used in making burlap and twine - was packed into the back of the joint, and molten lead was poured into the front of the jute packing creating a gas-tight seal. Over time, however due to ground movement, winter freeze-thaw cycles and the fact that jute is drying out causing it to shrink and/or crack, we are experiencing leaking joints. There is evidence that all Tier 3 mains (18-48" diameter) are less likely to fail through cracks and fractures, and more likely to fail due to leaks within the existing joints.

In the past Network Licensees would either fully replace these ageing assets or aim to maintain them. However, the availability of maintenance options has been fairly limited. Repair techniques have included mechanical joint clamps and encapsulants and since the 1980’s anaerobic sealant has been injected into the jute packing. While cheaper than full replacement, these repair techniques do have a number of disadvantages including high costs due to significant excavations and potential shut downs, causing customer dissatisfaction and road closures, and the associated restoration following the works. In 2009, Synthotech Limited, a innovative engineering company with a proven history of design, development, manufacture and supply services started work on a robotic platform; originally developed to provide an inspection system for 18" to 48" diameter gas mains and a laser scanning system for 355mm to 630mm polyethylene gas mains operating at pressures up to 2bar. This technical project explores the feasibility of expanding the capability of this robotic platform, "SynthoTrax", so that it can operate on a live network and seal leaking joints on larger diameter gas pipes internally, reducing the need for excavations to repair joints.

The purpose of the feasibility study is to investigate the potential to extend the capability of the prototype SynthoTrax architecture to enable remote internal joint sealing of gas pipes that: Are between 18" and 48" diameter metallic mainsCan operate at low pressure (; 75mbar) and medium pressure (>75mbar, Can remediate up to 400m of main from one excavationPotentially drill if requiredThe feasibility will also look into the individual system components, including a review of all other globallyavailable technology: Access FittingAccess SystemIn-pipe robotic platformSealant ApplicationSystemIn-pipe CCTVExternal Support SystemsTo ensure that this project meets the success criteria, regular meetings have been set up between the nominated project contact for SGN and the supplier. In these meetings project progress will be discussed and feedback in relation to the feasibility study will be frequently provided.

Note : Project Documents may be available via the ENA Smarter Networks Portal using the Website link above