What are ‘m’ and ‘y’ values and how do they relate to flange design?

The “y” value is the minimum stress needed to seat the gasket and create an initial seal. The “m” value is the multiplier that ensures the joint stays sealed under pressure. Together, they help determine the bolt load and flange strength required for reliable sealing. In short, your flange must compress the gasket enough to fill surface imperfections and resist internal pressure.