Pressure relief valve for a packaging container

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

a main body ( 4 ) with a single 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 ( 3 a ) 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 ), and

wherein the single central opening ( 9 ) is symmetrically disposed with respect to an entire perimeter of the main body ( 4 ).

2. The pressure relief valve as claimed in claim 1 , wherein the central through opening ( 9 ) tapers.

3. The pressure relief valve as claimed in claim 2 , wherein the central through opening ( 9 ) tapers in the direction of a side ( 7 ) facing an interior space ( 2 ) of the container.

4. The pressure relief valve as claimed in claim 1 , wherein a level of the annular bead ( 12 ) perpendicular to a center line (X-X) relative to the inner side ( 3 a ) of the packaging container is below a level of an inner edge ( 16 ) of the sealing surface ( 14 ) perpendicular to the center line (X-X).

5. The pressure relief valve as claimed in claim 1 , wherein the diaphragm ( 6 ) has a deformable surface ( 6 a ) oriented toward the sealing surface ( 14 ).

6. The pressure relief valve as claimed in claim 1 , further comprising an annular retaining device ( 22 ) formed integrally with the main body ( 4 ).

7. The pressure relief valve as claimed in claim 1 , wherein the recess ( 30 ) is formed in two stages with 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.

8. The pressure relief valve as claimed in claim 5 , wherein the diaphragm ( 6 ) has a surface made of EPDM or NBR or silicone rubber.

9. The pressure relief valve as claimed in claim 1 , wherein the central through opening ( 9 ) comprises a bottom region with a perforation therein.

10. The pressure relief valve as claimed in claim 1 , wherein the peripheral region ( 18 ) of the main body ( 4 ) has an inner ring ( 21 ), an outer ring ( 20 ) and a central ring ( 19 ) before a sealing operation on the packaging container ( 3 ), the central ring ( 19 ) projecting further outward from a base surface ( 25 ) than the inner ring ( 21 ) and the outer ring ( 20 ).

11. The pressure relief valve as claimed in claim 1 , wherein the central through opening ( 9 ) is of conically tapering design.

12. The pressure relief valve as claimed in claim 5 , wherein the diaphragm ( 6 ) is produced entirely from EPDM or NBR or silicone rubber.

13. The pressure relief valve as claimed in claim 1 , wherein the central through opening ( 9 ) is covered by means of a filter element ( 8 ).

14. The pressure relief valve as claimed in claim 7 , wherein the stepped region ( 32 ) is radially outside of the base recess ( 31 ).

15. The pressure relief valve as claimed in claim 7 , wherein a level of the stepped region ( 32 ) is above a level of the base recess ( 31 ).

16. The pressure relief valve as claimed in claim 7 , wherein a level of the annular bead ( 12 ) is above a level of the stepped region ( 32 ).

17. 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 ( 3 a ) 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 ( 6 a ) 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.

18. The pressure relief valve as claimed in claim 17 , wherein the central through opening ( 9 ) tapers.

19. The pressure relief valve as claimed in claim 18 , wherein the central through opening ( 9 ) tapers in the direction of a side ( 7 ) facing an interior space ( 2 ) of the container.

20. The pressure relief valve as claimed in claim 17 , wherein a level of the annular bead ( 12 ) perpendicular to a center line (X-X) relative to the inner side ( 3 a ) of the packaging container is below a level of an inner edge ( 16 ) of the sealing surface ( 14 ) perpendicular to the center line (X-X).