Transmission gearwheels are frequently exposed to extreme loads. Generally, in order to counteract premature wear, gearwheels made from steel are surface-hardened. This is carried out primarily by gas carburizing and subsequent quenching (case hardening). These processes of gas carburizing increase the carbon content in the boundary area of the workpiece and change the boundary structure of the steel. In the foundation, Institut für Werkstofftechnik (IWT) (Institute for Materials Engineering) in Bremen, they are engaged intensively with the various processes of heat treatment for the hardening of steel. As an alternative to gas carburizing using endogas, the nitrogen-methanol process, in which liquid methanol is directly introduced into the furnace, plays an important role and is gaining in importance. At the IWT, Liquid Flow Controllers (LFC), from Bürkert Fluid Control Systems, provide regulated and completely documented processes.