Manhole Extension Rings are for use on resurfacing projects to raise the elevation of the existing manhole assembly without having to remove the manhole frame from its embedded position.

Extension rings can be installed quickly and are cost effective as compared to digging out and resetting the existing manhole frame.

Extension rings are available for almost any rise specified. To utilize the existing cover the amount of rise (Dimension R) must be 1/2" greater in dimension than the thickness of the cover (Dimension X). New covers can be supplied when the rise is less than the 1/2" requirement.

Options

• Square
• Rectangular
• DOT

To Order, Specify
1. Pattern number of existing cover if available
2. Height of extension or rise or new overlay – Dimension R
3. Diameter of existing cover – Dimension C
4. Thickness of existing cover at bearing seat – Dimension X
5. Clear opening of existing frame D

R C X D                                                 R = Height of extension or rise or new overlay C = Diameter of existing cover X = Thickness of existing cover at bearing seat D = Clear opening frame