scope:

Scope of application

This technical code includes fundamentals for the design, dimensioning and installation of two-pipe systems as well as for the design and manufacture of two-pipe components made of thermoplastics. Prerequisites for the application of the technical code are experience in plastics processing and general piping construction as well as knowledge about the materials used.

The two-pipe systems dealt with in this technical code may be used to transport liquid and gaseous substances. They may be laid not only inside buildings, ducts and shafts but also outdoors. The dimensioning of buried two-pipe systems is not dealt with in this technical code as far as external loads are concerned.

This technical code should be consulted during the installation of two-pipe systems laid both above and below ground, especially whenever the use of a two-pipe system is specified because of particular dangers to people and the environment. Therefore, in the case of piping for the transport of environmentally-hazardous or toxic substances, an explicit agreement does not have to be made between the customer and the company with regard to the application of this technical code.

Two-pipe systems that serve process engineering purposes (e. g. with coolant in the annular space) are not covered by this technical code. With regard to the loads on the internal and external pipes, this application requires a different approach. Separate attention must be paid to any regulations, fundamental construction, testing and authorisation principles or official conditions that demand, extend or restrict the application of this technical code. Remarks about this are included in Section 2.