A multistage, centrifugal compressor used in high-pressure applications where the rotor is enclosed in a vertically split casing, resembling a barrel, and fitted with a suction and discharge nozzle. The compressor is designed to be dismantled without having to remove the barrel casing from the piping and foundation. Discharge pressures of up to 14,500 psi (1000 bar) are possible with a barrel casing design. Standards set by the industry (API, ASME) for this class of compressors result in large thick casings to maximize safety.
See also Casing Design.