Abstract: A hydraulic pressure booster device suited for increasing in-line fluid pressures comprises the assembly of a vertically oriented, tubular, closed end, housing for a submersible fluid pump. The pump is secured to a cap flange which closes the top of the tubular housing, while the bottom of the tubular housing is closed with either an anchor plate or blind end cap. Compression seal fittings are used to seal the penetration of pump motor pump lead wires through the cap flange. Inlet flow received into the tubular housing is drawn through the submersible pump with a resultant increase in hydraulic pressure at the output. A housing pressure sensing switch interrupts pump operation to prevent pump damage during periods of low fluid level in the housing. Additional pump protection is provided via a pump outlet pressure monitoring switch which regulates the pump delivery pressure. Dimensional design features of the device enhance useability and maintainability.