The Eureka cargo pumps is a vertical or horizontal pump with fixed speed or variable speed drive. To change speed during operation either a hydraulic coupling or frequency converter is used. Normally the motor and the pump is located in two separate rooms and a gas tight transmission is required. The pumps can be fitted with a priming unit on the suction side of each pump.
To ensure robust operation and prevent hydrocarbon gas to the atmosphere the pump include an API 682 pressurized mechanical seal arrangement.
The cargo pumps are used to unload crude oil from the cargo tanks onboard the FPSO to an adjacent crude oil tanker connected through a fiscal metering package and flexible unloading hose reel system. The pumps NPSH available are decreasing as the tank level is lowered during unloading. The pump speed must thus be decreased in several steps at low tank levels to ensure that the pump NPSH required are lower than NPSH available from the system and eliminate pump cavitation.
The pumps are mainly arranged in 3 x 50% or in 4×33% configuration with parallel operation. Hence, two or three pumps will typically operate while one of the pumps will typically be in stand-by.