Aniline Point of Petroleum Products

Aniline point is the minimum equilibrium  solution temperature, generally given  in F although C is also used, for  equal  volumes  of  aniline  and  oil. Aromatic  compounds in oils  contribute to a low  aniline point  which  in  turn  indicates that  such  an  oil will  soften or  swell  both  natural  and  most  synthetic  rubbers. Therefore  to  insure  minimum  action  on rubber  gaskets, seals, etc., oils  with high  aniline  points  should  be  selected. Solvent refined oils  as a  rule  satisfy  such  requirements.