400mm Line stop and 80mm PN25 UPT
The valve was on a bypass system connected to a 400mm ductile iron trunk main, with a running pressure between 18-20 bar. The valve was stuck in a half open position causing a restriction of flow on the network. The 3km pipeline could not be drained down. After careful consideration and close talks with the client the works were planned and carried out in the congested and restricted area containing other multiple services nearby.
Doocey Pipeline Resilience carefully exposed the high pressure main and South Staffs Water isolated the main 3km away. An under-pressure T and gate valve was installed allowing our specialists to perform an under-pressure drill. Once completed the ductile Iron trunk main was isolated by means of conventional ‘articulated head’ method of line stopping. Bespoke enhanced fittings were used to cope with the high pressure, and everything was tested carefully for 24 hours. Once the line stop had been installed to achieve isolation it was deemed safe to remove the inoperable 200mm valve and replace it with a new one. This specialist service prevented large volumes of water wastage.
A splendid Team effort on what has been a difficult and testing project. Yesterday’s effort combined with good weather contributed to the overall success of the scheme. Please pass on my thanks to the team for their professionalism and use of the specialist equipment supplied by your Company.
Paul Hipwood – Works Co-Ordinator, Area 2 South Staffs Water plc.