Expansion joint

An expansion joint for joining two adjacent parts of a pipe, the expansion joint comprising:

• an expansion bellows,
• an expanded wall and
• an inner sleeve assembly,
• wherein
• the expanded wall comprises a first wall part and a second wall part, wherein the first wall part and the second wall part are spaced apart from each other axially by an axial gap,
• the expansion bellows is connected to the first wall part and to the second wall part such that the axial gap between the first wall part and the second wall part is closed and such that the first wall part and the second wall part are connected flexibly,
• the expanded wall and the inner sleeve assembly limit at least one sealed chamber between each other, and
• the at least one sealed chamber is filled by a first gas, and wherein
• the inner sleeve assembly comprises a first metal part and a second metal part, wherein
• the first metal part is connected to the first wall part such that the first metal part and the first wall part limit a first sealed chamber between each other,
• the second metal part is connected to the second wall part such that the second metal part and the second wall part limit a second sealed chamber between each other, and
• the first sealed chamber and the second sealed chamber are adapted to be filled and pressurised by the first gas, and wherein
• the inner sleeve assembly, the expanded wall and the expansion bellows limit a third chamber between each other,
• the third chamber is in fluid connection with a flow channel, wherein the flow channel is limited by the inner sleeve assembly, and
• the third chamber is adapted to be filled and pressurized with a second gas, such that an over pressure within the third chamber is higher than a process pressure of the second gas within the flow channel within the expansion joint.