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Do you agree with new policy that reduces taxes for US producers of renewable chemicals?
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Biofuels International Conference 2013
11 September 2013 - 12 September 2013
Ramada Plaza, Antwerp, Belgium
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Biomass Asia Conference 2013
20 May 2013 - 22 May 2013
Kuala Lumpur, Malaysia |
World Biofuels 2013
23 May 2013 - 24 May 2013
Seville, Spain |
ILTA
3 June 2013 - 5 June 2013
Houston, Texas |
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Volume 4, Issue 3
Feature: Putting seals to the test |
An elastomer or rubber is a polymer with the property of elasticity. It is typically made up of carbon, hydrogen and sometimes fluorine, or in the case of silicone, oxygen and silicon atoms. Chemical or fluid absorption by an elastomer can lead to swelling of the seal. It is prone to attack by fluids exhibiting the same polarity, a phenomenon described as ‘like-dissolveslike’. For example, ethylenepropylene rubber (EPDM) is a non-polar elastomer, and as such, should not be used to seal non-polar solvents such as hexane. However, EPDM can be used to seal against polar fluids such as water. For many conventional petrol and diesel applications, NBR (nitrile butadiene rubbers) are widely used. There are a variety of grades available which, depending upon their acrylonitrile content, will have varying degrees of fuel and high temperature resistance. Increasingly, in hot under bonnet applications, FKM (fluorocarbon) rubbers are now being used due to their greater temperature resistance. However both these material types run a significant risk of swelling when exposed to biofuels and biofuel blends.
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