US Patent 7571743 Gravity flow isolation device

A device for isolating at least a portion of a pipe from fluid flowing therethrough. The device having a body (1) that is at least partially insertable into the pipe. An external surface of the body is adapted to abut with an inner surface of the pipe to substantially prevent fluid flowing therethrough. At least one valve element (10) is arranged within the body (1) and is selectively openable and closable to permit fluid to flow through the body to facilitate removal of the body from the pipe.