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Cork‑elastomer gaskets

Nebar is our range of rubber‑bonded cork gasket materials designed for sealing flat flanges against fluid leakage.

High grade, general purpose
General purpose, high quality cork-elastomer jointing. Below 3 mm thickness it comprises predominantly nitrile bonded cork; at 3 mm and above the cork is bonded with a polychloroprene / nitrile blend.

Recommended maximum system pressure is 0.5 MPa/5 bar. Consult us for use with higher pressures.

Prime features

  • Extensively used in the automotive, engineering and electrical industries
  • Suitable for a wide range of flanges
  • +110°C maximum operating temperature in liquids
  • Retains flexibility down to -20°C (<3 mm thickness) or -30°C (≥3 mm thickness)
  • Easy to cut handle and install

Specifications

  • Complies with ASEA 1169 5012E-204; and ASTM F104 line call out - <3 mm, F224000M2; ≥3 mm, F225000M2

Fluid compatibilities

  • Suitable for use with air, water, alcohols, fuel and diesel oils, mineral lubricating oils, mineral hydraulic fluids, water/glycol, ASTM Oil No 1, IRM903 oil, ASTM Fuel A, BS 148 Transformer Oil.

Physical properties

  • (Tested to ASTM F104 procedures)

<3mm thickness

  • Hardness, IRHD: 65 to 80 (ASTM D1415)  
  • Tensile strength, MPa minimum: 1.75 (ASTM F152B)
  • Compressibility at 2.8 N/mm², %: 15 to 30 (ASTM F36B)
  • Recovery, minimum %: 75 (ASTM F36B)
  • Fluid resistance, % volume change in:
  • ASTM Oil No 1, 72h at 100°C: -3 to +10 (ASTM F146)
  • IRM903, 72h at 100°C: 0 to +25 (ASTM F146)
  • ASTM Fuel A, 22h at ambient: -5 to +10 (ASTM F146)
  • BS 148 Transformer Oil, 14 days at 90°C: +23 (ASTM F146)

≥3mm thickness

  • Hardness, IRHD: 65 to 85 (ASTM D1415)
  • Tensile strength, MPa minimum: 1.75 (ASTM F152B)
  • Compressibility at 2.8 N/mm², %: 20 to 30 (ASTM F36B)
  • Recovery, minimum %: 75 (ASTM F36B)
  • Fluid resistance, % volume change in:
  • ASTM Oil No 1, 72h at 100°C: 0 to +10 (ASTM F146)
  • IRM903, 72h @ 100°C: +5 to +30 (ASTM F146)
  • ASTM Fuel A, 22h at ambient: 0 to +15 (ASTM F146)
  • BS 148 Transformer Oil, 14 days at 90°C: +8 (ASTM F146)

How supplied

  • Precision cut gaskets to any shape, size and quantity.
    In sheets 1.2 m x 1.2 m for thicknesses 0.75 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 4 mm, 5 mm, 6 mm, 6.4 mm. Sheets 0.9 m x 0.9 m for thicknesses 0.75 mm, 1.5 mm, 2 mm, 3 mm, 5 mm.

Neoprene electrical grade
Economical, high quality cork-elastomer jointing based on a polychloroprene/nitrile/SBR blend.

Recommended maximum system pressure is 0.5 MPa/5 bar. Consult us for use with higher pressures.

Prime features

  • Recommended for switchgear and transformers
  • +110°C maximum operating temperature in liquids
  • Retains flexibility down to -30°C

Specifications

  • Complies with ASTM F104 line call out F225000M2

Fluid compatibilities

  • Suitable for use with air, water, alcohols, fuel and diesel oils, mineral lubricating oils, mineral hydraulic fluids, water/glycol, ASTM Oil No 1, IRM903 oil, ASTM Fuel A, BS 148 Transformer Oil.

Physical properties

  • (Tested to ASTM F104 procedures)
  • Hardness, IRHD: 60 to 70 (ASTM D1415)
  • Tensile strength, MPa minimum: 1.45 (ASTM F152B)
  • Compressibility at 2.8 N/mm², %: 20 to 35 (ASTM F36B)
  • Recovery, minimum %: 75 (ASTM F36B)
  • Fluid resistance, % volume change in:
  • ASTM Oil No 1, 72h at 100°C: -5 to +10 (ASTM F146)
  • IRM903, 72h at 100°C: 0 to +30 (ASTM F146)
  • ASTM Fuel A, 22h at ambient: 0 to +15 (ASTM F146)
  • BS 148 Transformer Oil, 14 days at 90°C: +5 to +15 (ASTM F146)

How supplied

  • Precision cut gaskets to any shape, size and quantity. In sheets 1.2 m x 1.2 m. Thicknesses 1.5 mm, 2 mm, 2.5 mm, 3 mm, 5 mm, 6 mm, 9.5 mm.

Premium neoprene electrical grade
Premium quality cork-elastomer jointing, based predominantly on polychloroprene. Well proven over many years in heavy electrical plant.

Recommended maximum system pressure is 0.5 MPa/5 bar. Consult us first for use with higher pressures.

Prime features

  • Top grade product for switchgear and transformers
  • Developed for prolonged contact with mineral oils
  • +105°C maximum operating temperature in liquids
  • Retains flexibility down to -30°C

Specifications

  • Complies with ASTM F104 line call out F225000M2

Fluid compatibilities

  • Suitable for use with air, water, alcohols, fuel and diesel oils, mineral lubricating oils, mineral hydraulic fluids, water/glycol, ASTM Oil No 1, IRM903 oil, ASTM fuel A, BS 148 Transformer Oil.

Physical properties

  • (Tested to ASTM F104 procedures)
  • Hardness, IRHD: 65 to 85 (ASTM D1415)
  • Tensile strength, MPa minimum: 1.75 (ASTM F152B)
  • Compressibility at 2.8 N/mm², %: 20 to 30 (ASTM F36B)
  • Recovery, minimum %: 80 (ASTM F36B)
  • Fluid resistance, % volume change in:
    ASTM Oil No 1, 72h at 100°C: -5 to +10 (ASTM F146)
  • IRM903, 72h at 100°C: +10 to +30 (ASTM F146)
  • ASTM Fuel A, 22h at ambient: 0 to +15 (ASTM F146)
  • BS 148 Transformer Oil, 14 days at 90°C: +10 (ASTM F146)

How supplied

  • Precision cut gaskets to any shape, size and quantity. Sheets 1.2 m x 1.2 m. Thicknesses 0.75 mm, 1.5 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 6.4 mm, 8 mm, 9.5 mm.

Nitrile electrical grade
High quality, medium-to-hard grade of cork-elastomer jointing based on nitrile elastomer.

This material is able to withstand a higher degree of compression than other grades, which enables it efficiently to seal transformer lids (and other equipment) where flanges suffer a degree of non-parallelism. Moreover, its ability to withstand vapour phase drying removes the need for test gaskets.

Recommended maximum system pressure is 0.5 MPa/5 bar. Consult us first for use with higher pressures.

Prime features

  • Robust grade for heavy electrical duties
  • More resistant to over-compression than normal cork-elastomer grades
  • Suitable for out-of-parallel flanges, typically on transformer lids
  • Resists all commonly used transformer fluids
  • Withstands vapour phase drying
  • +110°C maximum recommended operating temperature in liquids - tolerates intermittent excursions to +120°C
  • Retains flexibility down to -20°C

Specifications

  • Complies with ASTM F104 line call out F225000M2

Fluid compatibilities

  • Suitable for use with air, water, alcohols, fuel and diesel oils, mineral and synthetic lubricating oils, mineral hydraulic fluids, water/glycol, ASTM Oil No 1, IRM903 oil, ASTM Fuel A, BS 148 Transformer Oil.

Physical properties

  • (Tested to ASTM F104 procedures)
  • Hardness, IRHD: 60 to 80(ASTM D1415)
  • Tensile strength, MPa minimum: 1.75(ASTM F152B)
  • Compressibility at 2.8 N/mm², %: 15 to 25  (ASTM F36B)
  • Recovery, minimum %: 75 (ASTM F36B)
  • Fluid resistance, % volume change in:
  • ASTM Oil No 1, 72h at 100°C: -5 to +15 (ASTM F146)
  • IRM903, 72h at 100°C: +5 to +20(ASTM F146)
  • ASTM Fuel A, 22h at ambient: +5 to +15 (ASTM F146)
  • BS 148 Transformer Oil, 14 days at 90°C:+1 to +10(ASTM F146)

How supplied

  • Precision cut gaskets to any shape, size and quantity. In sheets 1.2 m x 0.9 m for thicknesses 1.5 mm, 3 mm, 4 mm, 5 mm, 6 mm, 6.4 mm. Sheets 1.27 m x 1.014 m for thicknesses 1.5 mm, 5 mm.

For higher pressure duties
A high quality blend of cork and polychloroprene that withstands higher pressures and gasket loading than other Nebar grades, particularly in the electrical industry.

Recommended maximum system pressure is 0.6 MPa/6 bar. Consult us first for use with higher pressures.

Prime features

  • Developed for higher-pressure applications in switchgear and transformers
  • High resistance to mineral oils
  • +110°C maximum operating temperature in liquids
  • Withstands higher gasket loading than other Nebar grades
  • Retains flexibility down to -30°C
  • Easy to cut, handle and install

Specifications

  • Complies with ASTM F104 line call out F224000M2

Fluid compatibilities

  • Suitable for use with air, water, alcohols, fuel and diesel oils, mineral lubricating oils, mineral hydraulic fluids, water/glycol; plus ASTM Oil 1, IRM903 oil, ASTM Fuel A, and BS 148 Transformer Oil.

Physical properties

  • (Tested to ASTM F104 procedures)
  • Hardness, IRHD: 70 to 85 (ASTM D1415)
  • Tensile strength, MPa minimum: 2.35 (ASTM F152B)
  • Compressibility at 2.8 N/mm², %: 10 to 30 (ASTM F36B)
  • Recovery, minimum %: 75 (ASTM F36B)
  • Fluid resistance, % volume change in:
  • ASTM Oil No 1, 72h at 100°C: -5 to +5 (ASTM F146)
  • IRM903, 72h at 100°C: +10 to +30 (ASTM F146)
  • ASTM Fuel A, 22h at ambient: 0 to +10 (ASTM F146)
  • BS 148 Transformer Oil, 14 days at 90°C: +10 (ASTM F146)

How supplied

  • Precision cut gaskets to any shape, size and quantity. Sheets 1.2 m x 1.0 m for 0.75 mm thickness; sheets 1.2 m x 1.2 m for thicknesses 1.5 mm, 2.5 mm, 3 mm, 6 mm, 6.4 mm, 9.5 mm, 22 mm.

Premium nitrile electrical grade
Premium quality, medium hardness cork-elastomer jointing, based on nitrile rubber, that meets ABB specification for transformers and switchgear.

Recommended maximum system pressure is 0. 5Mpa/5 bar. Consult us first for use with higher pressures.

Prime features

  • Suitable for a wide range of duties
  • Used extensively in automotive, engineering and electrical industries
  • +110°C maximum operating temperature in liquids
  • Retains flexibility down to -25°C

Specifications

  • Meets ABB specifications for transformers and switchgear
  • Complies with ASTM F104 line call out F225000M2

Fluid compatibilities

  • Suitable for use with air, water, alcohols, fuel and diesel oils, mineral and synthetic lubricating oils, mineral hydraulic fluids, water/glycol, ASTM Oil No 1, IRM903 oil, ASTM Fuel A, BS 148 Transformer Oil.

Physical properties

  • (Tested to ASTM F104 procedures)
  • Hardness, IRHD 70 to 75 (ASTM D1415)
  • Tensile strength, MPa minimum: 1.75 (ASTM F152B)
  • Compressibility at 2.8 N/mm², %: 20 to 30 (ASTM F36B)
  • Recovery, minimum %: 80 (ASTM F36B)
  • Fluid resistance, % volume change in:
  • ASTM Oil No 1, 72h at 100°C: -2 to +10 (ASTM F146)
  • IRM903, 72h at 100°C: -2 to +15 (ASTM F146)
  • ASTM Fuel A, 22h at ambient: -2 to +10 (ASTM F146)
  • BS 148 Transformer Oil, 14 days at 90°C: +2.4 (ASTM F146)
  • Dow Corning 561 Transformer Fluid: -5 (Non-ASTM test)

How supplied

  • Precision cut gaskets to any shape, size and quantity. In sheets 1.2 m x 0.9 m. Thicknesses 1.5 mm, 3 mm, 5 mm, 6 mm.

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