Pressure relief valve for a packaging container

A pressure relief valve for a packaging container (3), the pressure relief valve comprising:

• a main body (4) with a central through opening (9), a sealing surface (14) and a peripheral region (18), wherein the peripheral region (18) can be sealingly connected to an inner side (3a) of the packaging container (3) and wherein the sealing surface (14) has an inwardly tapering form, and
• a diaphragm (6), which rests on the sealing surface (14) to permit sealing, a fluid (5) being arranged between the sealing surface (14) and the diaphragm (6),
• wherein the diaphragm (6) is flexible and wherein a recess (30) is formed in the main body (4),
• wherein the central through opening (9) opens into the recess (30), wherein at the central through opening (9), an annular bead (12) is disposed that projects in the direction of the diaphragm (6) and projects into the recess (30),
• wherein the diaphragm (6) has a deformable surface (6a) oriented toward the sealing surface (14), and
• wherein the recess (30) includes a base recess (31) and a stepped region (32), an outer contour of the base recess (31) corresponding substantially to an outer contour of an eight.