Annular barrier and downhole system for low pressure zone

An annular barrier for being expanded in an annulus between a well tubular structure and a wall of a borehole downhole for isolating a first zone from a second zone in the annulus between the well tubular structure and the wall of the borehole, the annulus having an annulus pressure, the annular barrier comprising:

• a tubular part for being mounted as part of the well tubular structure, the tubular part comprising an opening and an inside having an inside pressure,
• an expandable metal sleeve surrounding the tubular part and having an inner face facing the tubular part and an outer face facing the wall of the borehole,
• each end of the expandable metal sleeve being connected with the tubular part,
• an annular space between the inner face of the expandable metal sleeve and the tubular part, the annular space having a space pressure, and
• a valve system comprising a first valve and a second valve, the second valve allowing pressurised fluid into the annular space to expand the expandable metal sleeve and preventing fluid from flowing from the annular space to the inside of the tubular part,
• wherein the first valve has a first position allowing fluid communication between the inside of the tubular part and the second valve in order to expand the expandable metal sleeve to achieve an expanded position when increasing the inside pressure, and a second position providing fluid communication between the annular space and the annulus, wherein the first valve is configured to shift from the first position to the second position due to differential pressure when the space pressure is higher than the inside pressure, wherein the expandable metal sleeve is in the expanded position when the first valve is in the second position.