The pump-motor-module is built up from the approved SMPC pump cartridge and a pressure compensated electrical motor cartridge. The pump/motor cartridge is integrated into a “separator style” pressure casing.

Typically power transmission from electrical motor to the pumping elements  will be achieved by installing a mechanical coupling. Optionally a hydraulic torque or speed converter can be integrated.
The cartridges – motor, coupling, pump bearings, timing-gear and seals are filled with pressurised lube oil. The pressure of the lube oil is permanently controlled and adjusted to provide best operating conditions to the mechanical seals. Consequently the casing of the pump-motor-cartridges is pressure compensated against the pump casing pressure.
 
The pump-motor-module will be inserted into the pressure casing by avoiding all sensitive interfaces between pressure casing and pump/motor cartridge. The only mechanical interface between pump/motor cartridge and pressure casing is the anchor point at the pump casing cover plate. Deflections, deformations, mechanical stress, etc. from the casing will not be transmitted to the pump-motor cartridge.

Due to the fact, that the pressure casing unloads the pump/motor cartridge from sea-water-pressure, and the lube oil pressure unloads the cartridge from process pressure the new SMPC design is Double Pressure Compensated (DPC).

While the pump/motor cartridge design is mainly standardised, the casing is designed according to the actual project requirements. Different materials can be used, coating from inside can be done, composite material might be applied.

The pressure casing is a geometrical simple “separator style” pressure vessel. Therefore it provides good separation and liquid hold up capabilities – required for reliable multiphase and wet gas operation.

The DPC design also allows the vertical installation of the MPP. The diameter of the pump can be minimized – still providing sufficient separation and liquid hold up volume for reliable multiphase-service.