Since 1990, THI has designed and constructed, or revamped, over two dozen vacuum charge heaters for refineries in several different countries. These units range from small single-cell horizontal cabins (5 to 25 MM BTU/hr (2 to 8 MW) absorbed duty) to large twin-cell cabin or box heaters with total duties up to 150 MM BTU/hr (44 MW). The high temperatures and heat fluxes, low outlet pressures and near-sonic velocities in the process coils make designing these special heaters an engineering challenge. Tulsa Heaters, Inc. has the tools and experience to do it right!