US Patent 7703511 Pressure barrier apparatus

A pressure barrier apparatus 2 for providing a removable pressure barrier in a borehole is described. The apparatus comprises a housing 6, 8 defining a central bore 10 having a first part 20 and a second part 22 separated by an erodeable pressure barrier member 18. The housing also defines a second fluid flow passage 12 for connecting the first part to the second part, and a plurality of conduits 24 for directing fluid onto the barrier member. A sleeve 30 has a first condition in which fluid communication between the first part 20 and the second fluid flow passage 12 is prevented, and a second condition in which fluid is permitted to flow from the first part to the second fluid flow passage to cause erosion of the barrier member.