There are two major factors to be considered with regard to gasket seating. The first is the gasket material itself. The ASME Unfired Pressure Vessel Code Section VIII, Division 1 defines minimum design seating stresses for variety of gasket materials.
A seal is affected by compressing the gasket material and causing it to flow into the imperfections on the gasket seating surfaces so that intimate contact is made between the gasket and the gasket seating surfaces preventing the escape of the confined fluid. Basically there are four different methods that may be used either singly or in combination to achieve this unbroken barrier.
