Sealing device for a propeller shaft of a marine vehicle propulsion unit including a plurality of sealing lips axially offset relative to each other, with a receiving space for a hydraulic fluid delimited by two adjacent sealing lips, at least one buffer space axially offset with respect to the receiving space and delimited by two adjacent sealing lips, whereby the sealing device includes suitable feeding means for supplying the buffer space with a buffer fluid. The device includes a sampling circuit able to sample fluid included in the buffer space and a monitoring device able to check parameters of the fluid sampled by the sampling circuit.

System and methods are configured to adjust fluid pressure within a barrier fluid system on a subsea fluid processing machine. More specifically, a barrier fluid pressure system is located at the subsea location and includes a barrier fluid pressure regulator module having one input communicating or being pressure matched with a process fluid flowline and a second input communicating with the barrier fluid pressure system. The pressure regulator module is configured to locally adjust the barrier fluid pressure depending upon the fluid process pressure.

Sealing device for a propeller shaft of a marine vehicle propulsion unit including a plurality of sealing lips axially offset relative to each other, with a receiving space for a hydraulic fluid delimited by two adjacent sealing lips, at least one buffer space axially offset with respect to the receiving space and delimited by two adjacent sealing lips, whereby the sealing device includes suitable feeding means for supplying the buffer space with a buffer fluid. The device includes a sampling circuit able to sample fluid included in the buffer space and a monitoring device able to check parameters of the fluid sampled by the sampling circuit.

System and methods are configured to adjust fluid pressure within a barrier fluid system on a subsea fluid processing machine. More specifically, a barrier fluid pressure system is located at the subsea location and includes a barrier fluid pressure regulator module having one input communicating or being pressure matched with a process fluid flowline and a second input communicating with the barrier fluid pressure system. The pressure regulator module is configured to locally adjust the barrier fluid pressure depending upon the fluid process pressure.