Buna-N Gasket for 20" Single-Bolt Flush Manhole (Model #SB540-ORNG20)

Buna-N Gasket for 20" Single-Bolt Flush Manhole (Model #SB540-ORNG20)

The Model #SB540-ORNG20 is a heavy-duty, seamless replacement perimeter gasket engineered specifically for traditional 20" single-bolt flush manholes and tank tops. Fabricated from high-density Buna-N Nitrile rubber, this molded seal fits directly into the cover plate's seating channel to form an airtight, watertight seal. It is formulated to withstand the intense, localized center compression force typical of single-bolt clamping mechanisms, resisting long-term compression set and flattening over extended service lifecycles.

Key Features

  • High Compression Set Resistance: Engineered to maintain thickness and elastic memory under heavy, concentrated center structural clamping forces without stretching out of alignment.
  • Petroleum & Chemical Resilience: Excellent defense against degradation, swelling, or rotting when in constant contact with marine diesel, bilge water, hydraulic oil, or fuel sludge.
  • Seamless Loop Integrity: Factory-vulcanized as a solid continuous circle to prevent split-point or seam joint blowouts under static hydrostatic tank pressures.