Centrifugal pumps are common at many plants. Unfortunately, plants often suffer unnecessary pump downtime. Operating conditions not mentioned in the pump order document and not considered in pump design and manufacturing account for more than 75% of all unscheduled shutdowns. Alternative operating points and transient operating conditions are particular culprits. So, it's important to accurately indicate flow rates, required heads, liquid details and net positive suction head available for all possible operating scenarios for a pump.