EN 1861:1998

Foreword
Introduction
1 Scope
2 Normative references
3 Definitions
4 Classification, information content and
    presentation
5 Layout of diagrams
6 Selection of graphical symbols
Annex A (informative) Examples of flow diagrams for
refrigerating systems
Annex B (informative) Letter code, general symbols and
examples of measurement and control symbols
Annex C (informative) Bibliography

This European standard specifies the symbols and drawing rules for system flow diagrams and piping and instrument diagrams to be applied to refrigerating systems including heat pumps. These diagrams represent the configuration and function of refrigerating systems and form a part of the complete technical documentation necessary for designing, construction, installation, commissioning, operation, maintenance and decommissioning of a refrigerating system. This standard does not apply to refrigerating systems, where the heat is extracted by an electrical circuit, e.g. Peltier-effect.