Two feedwater heaters were initially custom built and required replacement. Field welding and measuring to fit take too much time during an outage. As-is condition models were requested and mapped in the field so that the end components designed and prefabricated would precisely fit and connect into the existing spool pieces and piping left in place after the old heater systems were removed.
The feedwater heaters were replaced during the nuclear outage. Heaters were leveled to fit on original supports and aligned so that five spool piece elbows on each heater fit concentric to heater nozzles, as well as to plant piping with bevels determined at their final positions even after field cuts were made and the effect of cold spring had settled. This all included required weld gap factored into cut lines marked by the metrology team.