Absolutely hot: Reliability at up to 300° C The equipment has been designed for positive circulation systems and keep oil as heat-transfer medium moving through the system at constant speed. Units of the D-range meet highest specifications. Our high-temperature systems are distinguished by robust design, high quality structural units as maximum safety is written large at Single. It goes without saying, that all our D-range equipment conforms to DIN 4754 as well as the UVV 64 (BG Chemie). The D-range is comprised of 7 structural units in its standard form, but can be extended by a multitude of optional extras.