Subsea pressure compensation system

1. A system for pressure compensation in a subsea environment, comprising:

a fluid filled enclosure surrounding a cavity in which electrical or mechanical equipment is housed,

a first pressure compensator having a first chamber and a second chamber, the first chamber being in fluid communication with the cavity, and

a second pressure compensator having a third chamber and a fourth chamber,

wherein the third chamber of the second pressure compensator is in fluid communication with the second chamber of the first pressure compensator,

wherein a first liquid is provided inside the cavity of the fluid filled enclosure and the first chamber of the first pressure compensator,

wherein a second liquid is provided inside the third chamber of the second pressure compensator and the second chamber of the first pressure compensator,

wherein the first chamber of the first pressure compensator is separated from the second chamber of the first pressure compensator by a first bellow, wherein the first bellow automatically adjusts itself in volume and stroke based on a first pressure difference between the first and second chambers of the first pressure compensator, and

wherein the third chamber of the second pressure compensator is separated from the fourth chamber of the second pressure compensator by a second bellow, wherein the second bellow automatically adjusts itself in volume and stroke based on a second pressure difference between the third and fourth chambers of the second pressure compensator.

2. The system of claim 1 , wherein each of the first and second bellows includes an element with a weight, the element arranged with respect to the respective bellow such that the weight of the element provides a force to reduce the stroke of the respective bellow.

3. The system of claim 1 , further comprising at least one of:

a first manifold connecting the fluid filled enclosure with the first chamber to allow a flow of a first fluid;

a second manifold connecting the third chamber with the second chamber to allow a flow of a second fluid; and

an inlet opening to the fourth chamber to allow a flow of sea water from a surrounding area of the system.

4. The system of claim 1 , wherein the fluid filled enclosure is enclosed by a further fluid filled enclosure surrounding a further cavity.

5. The system of claim 4 , wherein the first pressure compensator and the second pressure compensator are both enclosed by the further fluid filled enclosure and both surrounded by the same fluid.

6. The system of claim 4 , wherein the second chamber of the first pressure compensator has a first opening to the further cavity of the further fluid filled enclosure, and the third chamber of the second pressure compensator has a second opening to the further cavity, such as the third chamber of the second pressure compensator is in fluid communication with the further cavity and the second chamber of the first pressure compensator is in fluid communication with the further cavity.

7. The system of claim 4 , further comprising a manifold connecting the third chamber with the second chamber to allow a flow of the second fluid, wherein the manifold includes a connection to allow a flow of the second fluid to the further cavity of the further fluid filled enclosure.

8. The system of claim 4 , wherein both the first pressure compensator and the second pressure compensator are located outside the further fluid filled enclosure.

9. A system for pressure compensation in a subsea environment, comprising:

a fluid filled enclosure surrounding a cavity in which electrical or mechanical equipment is housed,

a first pressure compensator having a first chamber and a second chamber separated by a first bellow, wherein the first chamber is in fluid communication with the cavity, and

a second pressure compensator having a third chamber and a fourth chamber separated by a second bellow,

wherein the third chamber of the second pressure compensator is in fluid communication with the second chamber of the first pressure compensator,

wherein a first liquid is provided inside the cavity of the fluid filled enclosure and the first chamber of the first pressure compensator,

wherein a second liquid is provided inside the third chamber of the second pressure compensator and the second chamber of the first pressure compensator,

wherein the first chamber of the first pressure compensator is separated from the second chamber of the first pressure compensator by a first bellow, wherein the first bellow automatically adjusts itself in volume and stroke based on a first pressure difference between the first and second chambers of the first pressure compensator, and

wherein the third chamber of the second pressure compensator is separated from the fourth chamber of the second pressure compensator by a second bellow, wherein the second bellow automatically adjusts itself in volume and stroke based on a second pressure difference between the third and fourth chambers of the second pressure compensator.

10. The system of claim 9 , wherein each of the first and second bellows includes an element with a weight, the element arranged with respect to the respective bellow such that the weight of the element provides a force to reduce the stroke of the respective bellow.

11. The system of claim 9 , further comprising at least one of:

a first manifold connecting the fluid filled enclosure with the first chamber to allow a flow of a first fluid;

a second manifold connecting the third chamber with the second chamber to allow a flow of a second fluid; and

an inlet opening to the fourth chamber to allow a flow of sea water from a surrounding area of the system.

12. The system of claim 9 , wherein the fluid filled enclosure is enclosed by a further fluid filled enclosure surrounding a further cavity.

13. The system of claim 12 , wherein the first pressure compensator and the second pressure compensator are both enclosed by the further fluid filled enclosure and both surrounded by the same fluid.

14. The system of claim 12 , wherein the second chamber of the first pressure compensator has a first opening to the further cavity of the further fluid filled enclosure, and the third chamber of the second pressure compensator has a second opening to the further cavity, such as the third chamber of the second pressure compensator is in fluid communication with the further cavity and the second chamber of the first pressure compensator is in fluid communication with the further cavity.

15. The system of claim 12 , further comprising a manifold connecting the third chamber with the second chamber to allow a flow of the second fluid, wherein the manifold includes a connection to allow a flow of the second fluid to the further cavity of the further fluid filled enclosure.

16. The system of claim 12 , wherein both the first pressure compensator and the second pressure compensator are located outside the further fluid filled enclosure.