Patent ID: 8123226

Claim:
A seal assembly comprising: an inner pipe and an outer pipe in a double-walled subsea pipeline, wherein the inner pipe has a normal operating condition wherein it is connected and operable for transmitting a hydrocarbon through the inner pipe; an annular space formed between the inner pipe and the outer pipe wherein the annular space has a normal operating condition wherein it is connected and operable for permitting gas to pass through the annular space; and a seal in the annular space and operable for sealing the annular space, wherein the seal under the normal operating conditions of the inner pipe and the annular space is in a non-sealing position which allows passage of a gas through the seal assembly; and wherein under the normal operating conditions of the inner pipe and the annular space, the seal is actuatable from the non-sealing position to a sealing position in response to entry of liquid into the annular space.