Patent ID: 6293344
Filing Date: 2001-09-25
Classification: E21B

Abstract:
An apparatus for retaining fluid in a pipe, comprising:an elongated body adapted to be positioned within a subsea wellhead assembly, the elongated body having an end adapted for connection to the pipe, a flow passage for fluid communication with the pipe, and an outer surface for engagement with a sealing member in the subsea wellhead assembly;a first chamber defined within the elongated body and connected to receive pressure from one side of the sealing member in the subsea wellhead assembly; anda second chamber defined within the elongated body and connected to receive pressure from another side of the sealing member in the subsea wellhead assembly; anda valve supported in the elongated body adapted to be moved by pressure differential between the first and second chambers, the valve being movable between an open position to permit fluid flow through the flow passage and a closed position to prevent fluid flow through the flow passage.