This paper has been prepared as a case study looking at the refurbishment of critical valves that had previously been declared to be beyond economical repair. It describes the inspection and repair of two 900mm diameter Larner Johnson valves installed some 80 years ago. There were considerable challenges in gaining safe access to enable the valves to be removed from the outlet tunnel and taken back to the factory for refurbishment. Once the valves had been removed the gears and plunger were refurbished, bronze liners were cast and fitted, all iron surfaces were coated with epoxy paint and all bolts were replaced with stainless steel ones. The valves were successfully reinstalled and commissioned.
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