Specific heat


Refers to the amount of British thermal units (BTUs) required to raise one pound of fresh water (about one pint) one degree Fahrenheit, or the amount of calories needed to raise one gram (ml) of water one degree Centigrade.

A product with a low specific heat gets hot rapidly.

Oil has a low specific heat (about 0.5). Water has a specific heat of one (1), so oil will get twice as hot as water with the same amount of heat added to it. Oil also has a lower thermal conductivity than water.

This is the reason we do not recommend the use of oil as a buffer or barrier fluid between dual mechanical seals. Water would be the ideal fluid to use between dual seals except for two problems:

  • It’s corrosive.
  • It freezes.