High-pressure turbocompressors generally use closed-type three-dimensional impellers. Both the efficiency and the pressure coefficients are higher for three-dimensional impellers compared to conventional ones. Impellers are usually manufactured from low-alloy steels.
high-pressure turbocompressor applications are hydro-cracking, hydrogen-rich process gases (such as those in refineries), methanol plants, gas reinjection (or gas injection), high-pressure transportation pipelines, and some petrochemical processes such as polyethylene processes.