Processes and systems for the production for pressure management of a polymerization product flowing from a loop polymerization reactor to a separation vessel in a slurry polymerization system are disclosed herein. For example, a process comprises withdrawing a polymerization product slurry from a loop polymerization reactor, conveying the polymerization product slurry through a first line comprising a continuous take-off valve to yield a mixture comprising a vapor phase, wherein the mixture exits the continuous take-off valve, and conveying the mixture through a second line comprising a flashline heater so that the mixture has a Froude number in a range from about 5 to about 100.