US Patent 11280332 Valve and seat with seal

A valve and seat set has a seal coupled to the valve body, the seal surface comprising irregularities to allow pressure to propagate in-between the mating surfaces when pressure from the inside of the valve is equal to, or greater than, pressure from the outside of the valve. This allows the seal to lift in response to minimal differential pressure in the intended flow direction (from inside the valve), while effectively sealing pressure in the reverse direction (from outside the valve).