| 摘要 |
A valve assembly (2) which is configured to be coupled to a tubing string comprises a housing (8) defining a housing flow path (9) for communicating with the tubing string, and a barrier member (14) located in the housing (8) and configurable between a normally-closed position in which the barrier member (14) restricts access through the housing flow path (9), and an open position in which access is permitted through the housing flow path (9). The valve assembly (2) also comprises a bypass arrangement reconfigurable between an open state in which the bypass arrangement defines a bypass flow path that communicates with the housing flow path (9) on opposite sides of the barrier member (14) to permit fluid to bypass the barrier member and thereby fill the tubing string, and a closed state in which fluid is prevented from bypassing the barrier member to thereby permit press urization of the tubing string. |
