The knowledge of the heat transfer behaviour along a trace heating system is essential for the economic- and technically flawless design of a trace heating system. In general, we distinguish between two types of trace heating systems: •electric trace heating system •system which uses heat carriers. They differ from each other by the type of heating unit used. An electric trace heating system uses electric energy as power source. Electric current is flowing through a wire, where the electric current is converted into heat and further on is transferred into the product fluid across the electric trace heating system. Due to the fact that a heating cable needs electric current as power source, its application is limited in the petroleum processing industry. The other form of heat transfer applications is a trace heating system using heat carriers which are in general saturated steam, hot water or heat transfer oil. This system consists of a heat pipe which releases energy and a product pipe which absorbs energy. Thus, the heat is transported from the heat- to the product pipe. The advantage of a trace heating system using heat carriers compared to the usage of a heating cable is, that at least one of the three heat carriers is usually available as by-product in the petroleum processing industry. This thesis states the heat transfer behaviour of a trace heating system using heat carriers by heat transfer tests as well as by calculation approaches. Saturated steam was used as heat carrier in three defined cases, these are a distance- a bare- or a conduction trace heating system. Two different heat pipes were used comprising of carbon steel as well as of stainless steel. The heat transfer calculations were done by applying the Steady Flow Energy Equation. In total 18 heat transfer tests were executed with the objective of gaining a wider knowledge of the heat transfer behaviour. Saturated steam was used as heat carrier for all heat tracing experiments. During the whole work, the calculation model was proven for its accuracy and a final evaluation was done.