For special applications, cylindrical vessels can be supplied with a jacket for heating or cooling. Jacket is sealed to the vessel with Viton 'O' Ring and other sealing compositions. The seal prevents impermissible high stressess between vessel abd jacket and allows the movement which comes due to thermal expansion. These are of two type namely:-

• GLASS JACKETS
  Glass jacket can be used in a maximum operating pressure of 0.5 bar and a maximum operation temperature of 150oC.
• METAL JACKETS
  These vessels can also be supplied with metal jackets. Metal Jacket can be used in a maximum operating pressure of 2.0 bar and a maximum operation temperature of 150oC.