The T3 flagship valve is the PVS-T1EX parallel expanding gate valve. It protects al sealing surfaces in the open and closed position and prevents debris buildup in the body cavity. The operating clearances allow easy and smooth operation without danger of gate sticking. A through-conduit and full opening design reduces turbulence and pressure drop and allows for the smooth passing of pipeline pigs. The valve provides complete double block and bleed capability and isolates the body cavity to allow seat verification.