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Gas networks

Polyethylene has been adopted by the gas industry for the past 50 years as the plastic of choice for replacing old steel assets. As with all assets, plastic pipes will deteriorate over time but must remain safe even under the most arduous environmental conditions. At the same time, the polymer properties must remain functional to enable repair and maintenance. For the foreseeable future, the networks face a trilemma of reducing costs, maintaining safety and modernising. It is highly likely that in the future renewable hydrogen will form part of the gas mixture. The challenge will be the response and integrity of the pipe and joint assets as they age and are exposed to hydrogen. As polymer innovation experts we are already working on solutions.

On-site polymer analysis

After being buried in the ground for a time all yellow gas pipes can look the same, even to an experienced maintenance engineer. It is critical that before work starts, the identity of the pipe is known. Not knowing this information can lead to hazardous situations and overruns in cost. Gnosys have developed a portable system that will instantaneously determine the pipe polymer type, age and its physical properties and condition.

Electrofusion jointing

Commonly, plastic (PE) pipes have electrofusion jointing processes carried out on them over their lifetime for reasons of maintenance, repair or network extension. This technique has proven highly reliable if carried out using the correct procedure and compatible components. Gnosys have developed a method where the technician can ‘see’ and record whether the electrofusion joint is successful. This provides an evidential trail to ensure the jointing process is safe and successful.

Hydrogen in plastic pipes

Renewable hydrogen will likely be introduced in limited concentrations (<20% by volume) into the gas networks. To understand the affect this will have on existing assets, several key questions need to be managed scientifically. For instance, the long-term (>50 years) effect of hydrogen on the plastic pipe assets over their lifetime remains a point of conjecture. Gnosys are uniquely placed as advanced materials experts to answer these.

In-situ rehabilitation

The first plastic water and gas pipes were installed in the late 1960s. Some of these pipes are now beyond their design life and therefore due for scheduled replacement. Plastics when buried in the ground gradually lose their functional properties such as ductility. Gnosys, as polymer experts, believe there are some cost effective and practical ways to improve the properties of these pipes in-situ. This will extend the pipe life, save future replacement costs and all UK customers will benefit.

Self-healing pipes

Gas pipes statistically are likely to sustain (minor) damage such as abrasions in their lifetime.  This may occur in manufacture, installation, or due to operational and environmental factors. These types of damage create stress points which over time can produce cracks which propagate, especially as the pipe condition deteriorates to cause leaks. Gnosys have been working on new technologies to produce a polymer that self-heals, relieving the stress and restoring pipe integrity.

Forensic plastic pipes analysis

Gnosys have the in-house capability for forensically analysing plastic pipes and fittings as part of our service offering to the gas distribution community. This capability is based on our knowledge of the materials and construction methods used and modes of failure. For our clients, we can analyse failed or suspect pipes and joints from a consideration of macro and micro failure mechanisms. We report back the polymer properties, condition and likely mode of failure.  Our knowledge and developed techniques for this type of analysis is leading edge and world class.

Pit flooding protection

Many industries use below ground pits to house key assets. Examples of these include gas regulation or electrical transmission equipment. Since these pits are below ground, they are prone to flooding. The most common locations for water inflow are failed seals surrounding pipe or conduit wall penetrations, damaged sections of pit wall, and rainfall through poorly sealed pit lids.

Gnosys have developed a water blocking system that reduces the amount of water entering the pit and reduces maintenance costs for the operator. Firstly, penetration seals are reinforced using a special polymer arrangement. Secondly, the walls are sealed with a proprietary waterproof polymer coating that becomes waterproof. Uniquely this coating can be applied to damp and friable surfaces. Gnosys are seeking to partner with companies where this water protection service can be offered.