Both the Internal and External
Seals are made of rubber which conforms to
the physical requirements of ASTM C-923, as modified,
with a minimum 3/16 inch thickness for durability and resistance to puncturing and tearing.
The standard 8 inch Internal Seal (pictured above) is double pleated and the 10 inch WIDE
Internal Seal is triple pleated, the EXTRA-WIDE internal seal has four pleats to provide for a
minimum 2 inch vertical and/or 1/2 inch horizontal movement before stretching the material.
Flexibility of this material allows one size to fit a frame/chimney diameter range of more
than 20 percent.
The one piece channeled expansion bands are 1-3/4 inches wide and
are fabricated from high quality, corrosion resistant, 16 gauge stainless steel conforming
to the requirements of ASTM A-240 Type 304. The multiple transverse tab slots in the
bands provide for 2-1/2 inches of diameter range. An easy to use Installation Tool quickly expands the band to compress the rubber sleeve against the manhole frame and chimney.
Once expanded, the band is locked in place by the engagement of the locking tabs in the
proper slots, providing a flexible watertight seal.
The Internal 7 and 10 inch wide rubber extensions are made from the same material and have the same thickness as our internal sleeves. The top portion of the extension fits into the lower band recess of our internal chimney seal, under the lower band of the seal.
Tensile Strength: 1500 psi
Elongation at break: 350% min.
Hardness(Durometer): 48 +- 5
Accelerated oven-aging: max 15% decrease of tensile, 20% of elongation
Chemical resistance: no weight loss in 1N of sulfuric or hydrochloric acid
Compression set: 18% max. decrease
Water absorption: max. 10% increase by weight
Ozone resistance: rating 0
Low temperature brittle point: No fracture at -40 degrees C
Tear resistance: 200 lb. f/in.
Splice strength: 180 degree bend with no visible separation.
Prevents excess Inflow/Infiltration from entering your sanitary sewer system.
Cretex Company