SG meaning in oil and gas

Steam Generator

Application with respect to Waste Heat Recovery (WHR), and falls within two categories: drum type (usually refered to as Boilers or SGs, or Heat Recovery Steam Generators (HRSG), and drumless, universal or once through type [usually referred to as Once Through Steam Generators (OTSG), or Once Through Heat recovery Steam Generators (OTHRSG)]. Generally, when superheated steam is required a drum type SG is used. Where supercritical steam is required, usually a unviersal or once through SG is used. When subcritical steam, or wet steam is required, either type of SG can be used. In the case where lower quality Boiler Feed Water (BFW) is used to produce wet steam, it is typical to use a once through design.