fuel-cooled oil cooler (FCOC)
A heat exchanger in the form of a radiator, in which the fuel passes through the cooler's core while oil passes around the core. In this process, the heat of the lubricating oil is passed on to the fuel. A bypass valve (normally, a thermostatic valve), which routes the oil through the cooler only after the oil is heated up to a certain temperature, is provided in the system. Also called a fuel-oil cooler.