PRESSURE COMPENSATOR AND ASSEMBLY COMPRISING A SUBSEA INSTALLATION AND SUCH A PRESSURE COMPENSATOR

The invention proposes a double barrier pressure compensator for performing a pressure compensation between seawater surrounding a subsea installation and a medium filling a volume of the subsea installation. Said pressure compensator comprises: -a housing (20) having a first opening (202b) and a second opening (30); -a first bellows (4) and a second bellows (5) arranged one above the other within the housing (20) and each sealingly fixed to the housing (20) at their distal ends (43, 53); -a moving separation element (6) adapted to move inside the housing (20) and sealingly fixed to each of the proximal ends (44, 54) of the first and second bellows (4, 5) so as to separate a first compartment (21) from a second compartment (22) of the housing (20) sealed with respect to each other. Said pressure compensator (2) further comprising a third compartment (23) formed by a space between the housing (20) and the first and second bellows (4, 5), the first compartment (21) being arranged to be fluidly connected to the subsea installation (1) through the second opening (30), the second compartment (22) being arranged to be in communication with sea water through the first opening (202b), and said third compartment (23) being filled with a barrier medium.