A pressure regulator valve has a housing that defines a fluid passage and a flat seat disposed around an opening of the fluid passage and exit ports. A pin with a raised conforming elastomeric embossment that contacts the seat when the valve is closed is axially disposed in the housing. The pin is biased to maintain the elastomeric embossment in contact with the seat to maintain the valve closed and control an opening pressure of the valve. Flow of fluid through and out of the pressure regulator valve housing is controlled through adjustment of a level of this biasing. The fluid flows across the flat seat and between the flat seat and the embossment when the valve is open in such a manner that the flow is generally laminar and such that the valve minimizes pressure gain at the onset of flow.