Freeze isolation seal

The device of claim 9 wherein said baffle means comprises a perforated sheet.

A device for freezing liquid in a conduit by the use of a cryogenic fluid comprising a clamp assembly which comprises a plurality of pairs of generally semicylindrical segments which when assembled about a conduit extend around substantially the entire perimeter of the conduit, said clamp assembly fitting closely about the conduit to support the conduit while preventing direct contact between the conduit and the cryogenic fluid, and a housing adapted to surround the clamp assembly and to define a space between the clamp assembly and the housing for flow of the cryogenic fluid, the housing having an inlet and an outlet for cryogenic fluid.

A method of freezing liquid in a conduit comprising enclosing a section of the conduit within a tightly fitting clamping means for supporting the pipe wall against deformation under internal pressure and shielding the conduit, surrounding the clamping means with a housing spaced from the clamping means, and introducing a cryogenic fluid between said housing and said clamping means, and allowing cryogenic fluid to leave the housing.

A method for freezing liquid in a pipe comprising assembling a pipe clamp by joining together a plurality of clamp segments about a section of pipe to fit tightly around the pipe wherein liquid is to be frozen and supporting the pipe against deformation under internal pressure by means of said clamp, assembling a substantially leak proof housing surrounding said pipe clamp, introducing a controllable flow of cold gas into said housing for removing heat from said clamp and hence indirectly removing heat from said liquid, allowing heated gas to exit from said housing, sensing the temperature of heated gas near a point of exit from the housing, and controlling the rate of flow of gas into the housing in response to the temperature of the heated gas sensed.

Apparatus for freezing liquid in a conduit by the use of a cryogenic fluid comprising a clamp assembly for fitting tightly about a conduit wherein liquid is to be frozen to support the conduit against deformation under internal pressure while preventing direct contact between the conduit and the cryogenic fluid, a housing adapted to surround the clamp assembly and to define a space between the clamp assembly and the housing for flow of the cryogenic medium, the housing having an inlet adapted for connection to a supply of cryogenic fluid, an outlet for the exhaust of cryogenic fluid, and means for sensing the temperature of exhaust cryogenic fluid near said outlet.