Trelleborg FlexRib Chimney Seal

Trelleborg FlexRib Manhole Chimney Seal

The grade adjustment area of the manhole is the first to suffer deterioration caused by freeze /thaw cycles, traffic loading, thermal expansion and contraction of the surrounding pavement and other external forces


Needed to order DrainFlexRib Frame-Chimney Seal

Manhole Seal

A = Inside diameter of manhole frame

B = Inside diameter of grade adjustment area

C = Inside diameter of cone

D = Height of grade adjustment area (bottom of frame to top of cone)

E = Vertical surface on inside of manhole cone

T = Degree of taper on inside of frame

Available Widths

Trelleborg FlexRib Manhole Chimney Seals are made from a premium quality rubber compound and stainless steel bands which are designed to withstand the corrosive environment present in a sanitary sewer manhole

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One end of the FlexRib Extension is designed to fit under the FlexRib Seal, allowing them to span up to an additional 8 inches of adjustment. Multiple FlexRib Seal Extensions may be used to span taller grade adjustments.

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When the adjustment area of the manhole exceeds the range of the available FlexRib Seals, a FlexRib extension may be added to provide an additional 203 mm / 8” coverage.

Patented Tools

Manhole Seal

Manual Installation Tool

  • Works with a 1” socket or open ended wrench. 
  • Compress seal to 28 ft. lbs.
  • P/N 92003
Manhole Seal

Hydraulic Installation Tool

  • Force balanced heavy-duty construction develops 1½ tons of force. 
  • Compress seal to 4500 - 5000 psi.
  • P/N 91893


Trelleborg FlexRib Manhole Chimney Seal

Product information  

Download (pdf)

Technical Specifications

Technical Data Sheet  

Download (pdf)

Measurement worksheet

Purchasing aid  

Download (pdf)

Installation instructions

Technical Data Sheet  

Download (pdf)

Installation guide


Download (pdf)


Technical Approvals, Patents, Quality Standards

ASTM Logo black

International Standards

In conformance with worldwide standards


European Standards

In confirmance with European standards

Chimney Seal patent 1

U.S. Patent 

No. 92003 
Chimney seal patent 2

U.S. Patent

No. 91893


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