Manhole inserts and manhole insert gasket fabrication methods

1. A method of fabricating a manhole insert gasket on a manhole insert flange of a manhole insert suitable for deployment in a manhole opening of a manhole structure, comprising:

inverting the manhole insert having the manhole insert flange;

forming the manhole insert gasket by dispensing a liquid gasket material onto the manhole insert flange along at least one circular dispensing path, the liquid gasket material including a synthetic silicone elastomer; and

solidifying and hardening the gasket material by curing the gasket material to form the manhole insert gasket with the cured gasket material, whereby the manhole insert gasket with the cured gasket material remains exposed on the manhole insert flange prior to deployment of the manhole insert in the manhole opening.

2. The method of claim 1 wherein forming the manhole insert gasket comprises forming the manhole insert gasket having Shore Hardness of about 25 and an Adhesion to Stainless steel of about 580 psi.

3. The method of claim 1 wherein forming the manhole insert gasket comprises forming the manhole insert gasket having at least one annular gasket cord.

4. The method of claim 3 wherein forming the manhole insert gasket having the at least one annular gasket cord comprises forming the manhole insert gasket having the at least one annular gasket cord with a semicircular cross-section.

5. The method of claim 3 wherein forming the manhole insert gasket having the at least one annular gasket cord comprises forming the manhole insert gasket having the at least one annular gasket cord with a gasket thickness of about 1.59 mm.

6. The method of claim 3 wherein forming the manhole insert gasket having the at least one annular gasket cord comprises forming the manhole insert gasket including the synthetic silicone elastomer having a tensile strength of about 335 psi and an elongation of from about 400% to about 600%.

7. The method of claim 3 wherein forming the manhole insert gasket having the at least one annular gasket cord comprises forming the manhole insert gasket having an annular inner gasket cord and an annular outer gasket cord by dispensing the gasket material onto the manhole insert flange along a first circular dispensing path and a second circular dispensing path, respectively.

8. The method of claim 7 wherein forming the manhole insert gasket having the an inner gasket cord and the outer gasket cord by dispensing the gasket material onto the manhole insert flange along the first circular dispensing path and the second circular dispensing path, respectively, comprises forming the manhole insert gasket having a middle gasket space defined by and between the inner gasket cord and the outer gasket cord, the middle gasket space having a middle gasket space width of about 7 mm.

9. A method of fabricating a manhole insert gasket on a manhole insert flange of a manhole insert suitable for deployment in a manhole opening of a manhole structure, comprising:

inverting the manhole insert having a manhole insert bottom, a manhole insert sidewall extending from the manhole insert bottom, a manhole insert interior formed by and between the manhole insert bottom and the manhole insert sidewall and the manhole insert flange extending from the manhole insert sidewall, the manhole insert bottom, the manhole insert sidewall and the manhole insert fluidly sealing the manhole insert interior;

forming the manhole insert gasket having an annular inner gasket cord and an annular outer gasket cord by dispensing a liquid gasket material onto the manhole insert flange along a first circular dispensing path and a second circular dispensing path, respectively, the liquid gasket material including a synthetic silicone elastomer; and

solidifying and hardening the gasket material by curing the gasket material to form the manhole insert gasket with the cured gasket material, whereby the manhole insert gasket with the cured gasket material remains exposed on the manhole insert flange prior to deployment of the manhole insert in the manhole opening.

10. The method of claim 9 wherein forming the manhole insert gasket having the annular inner gasket cord and the annular outer gasket cord comprises forming the manhole insert gasket having the annular inner gasket cord and the annular outer gasket cord each with a semicircular cross-section.

11. The method of claim 9 wherein forming the manhole insert gasket having the annular inner gasket cord and the annular outer gasket cord comprises forming the manhole insert gasket having the annular inner gasket cord and the annular outer asket cord each with a gasket thickness of about 1.59 mm.

12. The method of claim 9 wherein forming the manhole insert gasket having the annular inner gasket cord and the annular outer gasket cord comprises forming the manhole insert gasket including the synthetic silicone elastomer having a tensile strength of about 335 psi and an elongation of from about 400% to about 600%.

13. The method of claim 9 wherein forming the manhole insert gasket comprises forming the manhole insert gasket having Shore Hardness of about 25 and an Adhesion to Stainless steel of about 580 psi.

14. The method of claim 9 wherein forming the manhole insert gasket having the annular inner gasket cord and the annular outer gasket cord comprises forming the manhole insert gasket having the annular inner gasket cord and the annular outer gasket cord by dispensing the gasket material onto the manhole insert flange along a first circular dispensing path and a second circular dispensing path, respectively.

15. The method of claim 14 wherein forming the manhole insert gasket having the annular inner gasket cord and the annular outer gasket cord by dispensing the gasket material onto the manhole insert flange along the first circular dispensing path and the second circular dispensing path, respectively, comprises forming the manhole insert gasket having a middle gasket space defined by and between the annular inner gasket cord and the annular outer gasket cord, the middle gasket space having a middle gasket space width of about 7 mm.

16. A method of fabricating a manhole insert gasket on a manhole insert flange of a manhole insert suitable for deployment in a manhole opening of a manhole structure, comprising:

inverting the manhole insert having a manhole insert bottom, a manhole insert sidewall extending from the manhole insert bottom, a manhole insert interior formed by and between the manhole insert bottom and the manhole insert sidewall and the manhole insert flange extending from the manhole insert sidewall, the manhole insert bottom, the manhole insert sidewall and the manhole insert flange fluidly sealing the manhole insert interior;

forming the manhole insert gasket having a discrete annular inner gasket cord and a discrete annular outer gasket cord structurally distinct from the inner gasket cord by dispensing a liquid gasket material onto the manhole insert flange along a first circular dispensing path and a second circular dispensing path, respectively, the liquid gasket material including a synthetic silicone elastomer having a tensile strength of about 335 psi and an elongation of from about 400% to about 600%; and

solidifying and hardening the gasket material by curing the gasket material to form the manhole insert gasket with the cured gasket material whereby the manhole insert gasket with the cured gasket material remains exposed on the manhole insert flange prior to deployment of the manhole insert in the manhole opening.

17. The method of claim 16 wherein forming the manhole insert gasket having the annular inner gasket cord and the annular outer gasket cord comprises forming the manhole insert gasket having the annular inner gasket cord and the annular outer gasket cord each with a gasket thickness of about 1.59 mm.

18. The method of claim 16 wherein forming the manhole insert gasket having the annular inner gasket cord and the annular outer gasket cord by dispensing the gasket material onto the manhole insert flange along the first circular dispensing path and the second circular dispensing path, respectively, comprises forming the manhole insert gasket having a middle gasket space defined by and between the annular inner gasket cord and the annular outer gasket cord, the middle gasket space having a middle gasket space width of about 7 mm.

19. The method of claim 1 wherein forming the manhole insert gasket comprises forming the manhole insert gasket having Shore Hardness of about 25 and an Adhesion to Stainless steel of about 580 psi.