| 摘要 |
A valve assembly includes a valve body having a fluid access passage extending from a process fluid port to an access port, a block valve disposed in the fluid access passage and movable between open and closed conditions, an access blocking device disposed in the fluid access passage between the access port and the block valve, and a valve interlock arrangement. The access blocking device is movable from an access blocking condition in which access to the block valve through the access port is blocked, to an access permitting condition in which access to the block valve through the access port is permitted. The valve interlock arrangement is configured such that the block valve is prevented from being moved to the closed condition when the access blocking device is in the access permitting condition. |
