Patent ID: 9570224
Date: 2017-02-14
CPC Classifications: E21B,F15B,H01F,H05K,Y10T

Claim:
1. A pressure compensation system for compensating volume variations of a liquid in a chamber of a subsea device, the pressure compensation system comprising: a subsea enclosure of the subsea device enclosing the chamber; a first pressure compensator comprising a first compensation volume and configured to provide a first pressure balancing between ambient medium surrounding the subsea device and the first compensation volume, wherein a flow connection is provided between the first compensation volume and the chamber; a first biasing device configured to bias the first pressure compensator such that a pressure in the first compensation volume is higher than a pressure in the ambient medium surrounding the subsea device; a second pressure compensator comprising a second compensation volume and configured to provide a second pressure balancing between ambient medium surrounding the subsea device and the second compensation volume, wherein a flow connection is provided between the second compensation volume and the chamber; a second biasing device configured to bias the second pressure compensator such that a pressure in the second compensation volume is higher than a pressure in the ambient medium surrounding the subsea device; a controllable first valve arranged in the flow connection between the first compensation volume and the chamber, the first valve configured to stop fluid flow between the first compensation volume and the chamber; a controllable second valve arranged in the flow connection between the second compensation volume and the chamber, the second valve configured to stop fluid flow between the second compensation volume and the chamber; and a control unit connected to the first valve and the second valve, wherein the control unit is configured to have a mode of operation in which the first valve is open and the second valve is closed so as to provide pressure compensation of the chamber by the first pressure compensator and to maintain the second pressure compensator in standby, and wherein the control unit is configured to automatically shut the first valve and automatically open the second valve upon detecting a failure of the first pressure compensator.