GroupMetropolitan were asked by a long standing client, Citi Bank, to identify why they could not isolate a number of their valves across their condense water and chilled water systems.
After some investigation, Team Mechanical identified that the valves in question had developed issues with sealing and as such were letting water pass. These valves were critical for the planned isolations of various sections of the system to enable a large refit project to commence, so replacement was the only option.
We engaged with a key supply chain partner to develop a pipe freezing strategy that would allow isolation & replacement over 1 weekend for each valve. This would minimise system downtime and ensure services were back online for BAU on Monday morning.
The client had concerns around thermal shock to the pipework, considering the valves were between 500mm and 600mm. We developed a twin lined freezing jacket which ensured no liquid nitrogen came into direct contact with the surface of the pipework.
The building was over 33 floors which resulted in system pressures around 20Bar at basement level, so a lot of planning went into the methodology o ensure we worked safely and didn’t put any of our staff or the client premises at risk.
The isolation valves were successfully installed over a 12 week period, consuming 135,000ltrs of liquid nitrogen and over 2500 unsociable man hours worked between Team Mechanical, Team Electrical & Team BMS.
The client was very impressed with the way in which the project was developed, planned & delivered. This has resulted in further enquiries from other key blue chip clients for similar works.