This document specifies rules and conventions for the execution of simplified drawings for the representation of all kinds of pipes and pipelines made of all sorts of materials (rigid and flexible). It is used whenever it is necessary to represent pipes or pipelines in a simplified manner. For the purposes of this document, the figures illustrate the text only and should not be considered as design examples. NOTE This document can also be used for the representation of similar installations, such as ventilation or air-conditioning systems; in such cases, the term duct , etc. is substituted for the term pipe .