Abstract: A method of controlling fluid pressure in a closed system including using a pressure regulating unit connected to the system, the unit including a first conduit fluidly connecting the closed system to an external system. A first regulating valve is interposed between the external system and one end of the conduit and a second regulating valve interposed between the closed system and the other end of the conduit. The method further includes: a) opening one of the first or second regulating valves; b) closing said one regulating valve; c) opening the other regulating valve; d) closing the other regulating valve; and e) repeating steps a) to d) in turn until the desired fluid pressure is achieved in the system.

Abstract: A subsea pump is used in applications such as deep-water boosting of fluid produced from a wellbore. The process pressure variation is mostly related to the pump suction side in such applications. The barrier fluid system for the pump regulates its pressure according to the pump discharge pressure. A balance piston is positioned in a location close to the pump inlet such that both mechanical seals are exposed to the pump discharge pressure on the process side.

Abstract: A subsea pump is used in applications such as deep-water boosting of fluid produced from a wellbore. The process pressure variation is mostly related to the pump suction side in such applications. The barrier fluid system for the pump regulates its pressure according to the pump discharge pressure. A balance piston is positioned in a location close to the pump inlet such that both mechanical seals are exposed to the pump discharge pressure on the process side.

Abstract: The present invention relates to a dynamic sealing system device for a submerged pump comprising at least one feed line running in towards the dynamic sealing system, with a first valve device arranged in the feed line and a second valve device arranged such that in an open position it opens a first bypass line that runs from a point on the feed line between the first valve device and the pump and a low-pressure source at the pump to reduce the pressure in a barrier fluid in the sealing system. The invention also comprises a method for reducing the barrier fluid pressure for a submerged pump.

Abstract: A system to pressurize barrier fluid of a submersible installation to provide a differential pressure between the ambient pressure surrounding the submersible installation and the pressure of the barrier fluid internally in the submersible installation during submersion of the system, wherein the differential pressure fits within a predetermined differential pressure range. The system comprises a pre-charge arrangement and a pressure intensifier which is adapted to start working at a start-up pressure. The pre-charge arrangement is adapted, during submerging of the system, to provide a differential pressure within the predetermined differential pressure range until the ambient pressure equals the start up pressure of the pressure intensifier, while the pressure intensifier is adapted to provide a differential pressure within the predetermined differential pressure range when the ambient pressure equals the start-up pressure of the pressure intensifier during further submersion of the system.

Abstract: A method of controlling fluid pressure in a closed system including using a pressure regulating unit connected to the system, the unit including a first conduit fluidly connecting the closed system to an external system. A first regulating valve is interposed between the external system and one end of the conduit and a second regulating valve interposed between the closed system and the other end of the conduit. The method further includes: a) opening one of the first or second regulating valves; b) closing said one regulating valve; c) opening the other regulating valve; d) closing the other regulating valve; and e) repeating steps a) to d) in turn until the desired fluid pressure is achieved in the system.

Abstract: A system to pressurize barrier fluid of a submersible installation to provide a differential pressure between the ambient pressure surrounding the submersible installation and the pressure of the barrier fluid internally in the submersible installation during submersion of the system, wherein the differential pressure fits within a predetermined differential pressure range. The system comprises a pre-charge arrangement and a pressure intensifier which is adapted to start working at a start-up pressure. The pre-charge arrangement is adapted, during submerging of the system, to provide a differential pressure within the predetermined differential pressure range until the ambient pressure equals the start up pressure of the pressure intensifier, while the pressure intensifier is adapted to provide a differential pressure within the predetermined differential pressure range when the ambient pressure equals the start-up pressure of the pressure intensifier during further submersion of the system.

Abstract: The present invention relates to a dynamic sealing system device for a submerged pump comprising at least one feed line running in towards the dynamic sealing system, with a first valve device arranged in the feed line and a second valve device arranged such that in an open position it opens a first bypass line that runs from a point on the feed line between the first valve device and the pump and a low-pressure source at the pump to reduce the pressure in a barrier fluid in the sealing system. The invention also comprises a method for reducing the barrier fluid pressure for a submerged pump.