scope:

Introduction and Scope

In industry, preference is given to indirect methods for transferring heat and for heating or cooling. Many processes necessitate uniform heating at high temperatures. Direct heating often entails difficulties, particularly if the materials concerned are sensitive to heat, because the likelihood of local overheating and thermal decomposition cannot always be excluded. It is for this reason that indirect heating holds out advantages in many cases and has thus become firmly established. An additional benefit is offered by organic heat-transfer media in that they permit Operation at atmospheric pressure if the temperature is about 350 °C or less or at moderate pressures if the temperature is higher than 350 °C.

The heat-transfer medium in a heat exchanger is brought to a given temperature in a heater and led to the heat consumer, to which it releases heat. It is then returned to the heater.

This Guideline applies to heat exchangers that fall within the scope of the German boiler and pressure vessel Code {Druckbehälter-Verordnung), the relevant safety regulations {Unfallverhütungsvorschrift VBG 64), and the Standard DIN 4754. A supplementary Guideline, VDI 03033, contains forms for the documentation required to verify that heat exchangers are operated in conformance with regulations.