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Sealing Materials Selection
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Material Identification
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Temperature Range
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Nitrile (NBR)
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(Std.)
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-40°F to +240°F
-40°C to +115°C
Resistant to high pressure, oil, hydraulic oil, water, air, gasoline, kerosene, anhydrous ammonia and also coolant. (Methanol excluded)
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Viton® (FKM)
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V
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-15°F to +400°F
-26°C to +204°C
Resistant to high pressure, oil, hydraulic oil, water, air, mineral oils, gasoline, kerosene and also coolant. (Methanol excluded)
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EPDM (EP)
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E
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-60°F to +300°F
-50°C to +150°C
Not Suitable for Oils.
Resistant to water, steam, inert gasses, coolant and also suitable for many fire resistant fluids.
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Neoprene (CR)
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Q
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-65°F to +285°F
-55°C to +140°C
Moderately resistant to petroleum oils and weathering (UV).
Used extensively for sealing refrigeration fluids.
Has good abrasion resistance.
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Temperature:
It is important to ensure that the sealing temperatures are maintained, as listed in the above chart. Be aware that extreme temperatures of hot or cold can affect the material properties. Extreme cold temperatures cause the sealing material to crack and subsequently reduce the ability to seal effectively. Extreme hot temperatures can cause the sealing material to breakdown and may affect spring tension.
Example: For every 7°F/4°C rise in temperature in the system, above the maximum specified seal temperature, it is estimated that seal life will reduce by half (for Nitrile).
