Removable thief hatch plug

1. An apparatus configured to substantially preclude the release of gases through a hatch in a tank, said tank having a thief hatch opening, said apparatus comprising:

a first rigid plate having a first diameter and a first center hole;

a second rigid plate said second rigid plate having a second diameter;

a flexible disk said flexible disk having a third diameter, said flexible disk positioned between said first rigid plate and said second rigid plate;

a shaft passing through said first center hole, a second center hold and a third center hole, a first end of said shaft protrudes beyond said first rigid plate and said first end of said shaft carries threads, a second end of said shaft protrudes beyond said second rigid plate and carries a handle;

a first nut positioned on said first end of said shaft; and,

a second nut positioned on said shaft adjacent to said second rigid plate, said first nut and said second nut retain said first rigid plate, said second rigid plate and said flexible disk on said shaft.

2. The apparatus of claim 1 , wherein said third diameter is from about 8.25 inches to about 9 inches.

3. The apparatus of claim 1 , wherein said first diameter is about 12% smaller than the third diameter.

4. The apparatus of claim 1 , wherein said first diameter is a diameter proximate to the diameter of said thief hatch opening.

5. The apparatus of claim 1 , wherein said first diameter is from about 6.5 inches to 7.95 inches.

6. The apparatus of claim 1 , wherein said second diameter is about 35% to about 45% less than the third diameter.

7. The apparatus of claim 1 , wherein said second diameter is about 4.5 inches to about 5.5 inches.

8. The apparatus of claim 1 , wherein said laterally extending arms are carried by said second end of said shaft and each of said laterally extending arms extends outward from said shaft a distance of about four inches to about six inches.

9. The apparatus of claim 1 , wherein each of said laterally extending arms terminates in a downward projecting hook.

10. An apparatus configured to substantially preclude the release of gases through a hatch in a tank, said tank having a thief hatch opening, said apparatus comprising:

a first rigid plate having a first diameter and a first center hole;

a second rigid plate said second rigid plate having a second diameter where said second diameter is less than said first diameter and having a second center hole;

a flexible disk said flexible disk having a third diameter where said third diameter is greater than said first diameter and having a third center hole, said flexible disk positioned between said first rigid plate and said second rigid plate;

a shaft passing through said first center hole, said second center hole and said third center hole, a first end of said shaft protrudes beyond said first rigid plate and said first end of said shaft carries threads, a second end of said shaft protrudes beyond said second rigid plate and carries a handle;

first and second laterally extending arms carried by either said second end of said shaft or said handle;

a first nut positioned on said first end of said shaft; and,

a second nut positioned on said shaft adjacent to said second rigid plate, said first nut and said second nut bias said first rigid plate and said second rigid plate against said flexible disk.

11. The apparatus of claim 10 , wherein said third diameter is from about 8.25 inches to about 9 inches.

12. The apparatus of claim 10 , wherein said first diameter is about 12% smaller than the third diameter.

13. The apparatus of claim 10 , wherein said first diameter is a diameter proximate to the diameter of said thief hatch opening.

14. The apparatus of claim 10 , wherein said first diameter is from about 6.5 inches to 7.95 inches.

15. The apparatus of claim 10 , wherein said second diameter is about 35% to about 45% less than the third diameter.

16. The apparatus of claim 10 , wherein said second diameter is about 4.5 inches to about 5.5 inches.

17. The apparatus of claim 10 , wherein said laterally extending arms are carried by said second end of said shaft and each of said laterally extending arms extends outward from said shaft a distance of about four inches to about six inches.

18. The apparatus of claim 10 , wherein each of said laterally extending arms terminates in a downward projecting hook.