Trim the impeller on the upstream pump to achieve the correct net discharge head. Both pumps do NOT have to be the same trim (think about an OH pump feeding a BB3). Install a bypass line with check valves. Then start the upstream pump first to allow it to pack the line before starting the...
On the original question, and for everyone else, with regards to a project, you must realize that a pump is not finished after it has been engineered and manufactured. It must still be installed and operated. At times, this is more critical to reliability and efficiency than the former...
On Dubmac's point the pump has definitely been refurbished since '66, although not necessarily by the original manufacturer. Typically, there will be an additional nameplate on the casing of the shop that performed the work. That being said, it could have been restored to OEM spec or updated to...
