Gaskets and Sheet Jointings

Nebar® Purple

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

Upgraded replacement for Nebar® N67.

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 suiffer a degree of non-parallelism. Moreover, its ability to withstand vapour phase drying removes the need for test gaskets.

Recommended maximum system pressure is 0.5Mpa/5bar. May be used for higher pressures in consultation with James Walker Technical Support Team.

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.

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 @ 2.8N/mm², %:  15 to 25  (ASTM F36B)
Recovery, minimum %:  75  (ASTM F36B)
Fluid resistance, % volume change in:
ASTM Oil No 1, 72h @ 100°C:  -5 to +15 (ASTM F146)
IRM903, 72h @ 100°C: +5 to +20  (ASTM F146)
ASTM Fuel A, 22h @ ambient: +5 to +15 (ASTM F146)
BS 148 Transformer Oil, 14 days @ 90°C:  +1 to +10  (ASTM F146)

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

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