Manhole inserts and manhole insert gasket fabrication methods

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.

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.