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Gaskets and Sheet Jointings

Nebar® Purple

Description
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.

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 @ 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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