The Groth Model 8200 Roof Manhole Cover is used when quick and easy access is desired. It is generally placed on digester covers or roofs. It is required in most cases by insurance underwriters to be non-sparking and gas tight. The seal is provided by a Buna-N diaphragm and the surface bearing is distributed evenly all around by the design. The model 8200 incorporates a positive cover lockdown which assures a premium type seal on digester tanks with internal pressures up to 1 psig.
Size: 18" (DN 450), 20" (DN 500), 24" (DN600), 30" (DN750), and 36" (DN900) **type 356, 18" - 24" only
Material: Available in aluminum*, carbon steel, stainless steel, fiberglass and other materials