For over 120 years, Parr Instrument Company has been designing, manufacturing, and selling high quality laboratory instruments and apparatus for conducting chemical reactions and tests under heat and pressure and for testing fuels. Parrs extensive product line includes stirred reactors, pressure vessels, and high pressure tubular reactors for the study of catalytic and non-catalytic reactions in batch, continuous-flow, and multiple/parallel operation for the chemical, polymer, biofuels, hydrometallurgical, pharmaceutical, petroleum, and petrochemical industries. Custom designed complex reactor systems, built to the customer's specifications and requirements are also provided. Parrs oxygen combustion calorimeters are used for the determination of the heat of combustion in solid, liquid, and refuse-derived fuels for the energy, educational, coal, and fuel testing industries. Parr also offers sample preparation vessels for extraction, digestion, and hydrothermal synthesis, as well as a line of vessels for cell disruption by nitrogen decompression.