When a major foodstuff manufacturer in London needed to upgrade their vital gas supply, the Service Delivery team at National Grid Metering stepped up to design, build and commission a solution, while keeping the site operational.
The site provided several obstacles the team had to overcome, but it was key that the factory needed to stay operational 24/7. The initial proposal put forward to the customer was rejected as it would have required a five day gas outage, so an engineering solution was developed by the project team, headed up by Senior Integrity Engineer, Mark Tarran, that would allow the work to be complete with no interruption to the gas supply. Mark reached an agreement with Cadent Gas, the incumbent Gas Distributor, to use a ‘new’ Emergency Control Valve (ECV) for the site that was previously installed by the network as a valve for use during pipeline inspections.
This project, designed by National Grid Metering and supported in the delivery by service partner AllGas1, facilitated a constant gas supply during the works through the original ECV and one regulated stream that fed the gas meter and customer outlet. Meanwhile the second stream was removed, and the use of the ‘new’ valve allowed the new module to be installed along with a new outlet pipe to be connected between the new module and the removed stream outlet valve to ensure no downtime for the client. The new installation was then commissioned and took over control of the gas supply, before the rest of the existing asset was decommissioned and removed.
Part of the scope was to reduce the risk of the asset by removing a 25m high x 36” diameter creep relief vent stack that was adjacent to the main loading entrance for the factory, HS2 railway line and London City Airport. By re-designing the creep relief of the new module the hazardous area zone was reduced from an 80m(h) x 44m(diameter) zone to a 2.5m(h) x 10m(diameter) zone, and in total the new module design created a 50% reduction in the footprint within the gas compound.
All remaining original pipework had pipe supports replaced, grit blasted and painted to T/SP/PA/10 (four coat system) to futureproof the installation.
Mark Tarran said of the project: “After identifying the problems with our client, we designed a solution that delivered what they wanted, within a timeframe acceptable to all. Despite the coronavirus lockdown occurring in the middle of the job which postponed activity at site for several weeks, we still managed to commission the new install in June.
"Through it all we maintained the gas supply to site allowing them to continue operating with minimal inconvenience, while National Grid Metering and our service partner Allgas1 delivered a complex project and overcame significant obstacles.”