Nope no valve. It is for comfort only. N95 is the only thing that matters. The mask is as much to prevent you from inadvertently touching your nose and mouth as it is to filter out the virus in water droplets. The virus itself is small enough to pass through but it is transported in droplets that will not pass.
The mask is as much to prevent you from inadvertently touching your nose and mouth.
How many times does the average person touch their mouth/face/eyes with their hands in an hour?