C- 15 01 12-87 2hT6TOO EO6TS9h ISO INTERNATIONAL STANDARD 12 Second edition 1987-05-01 INTERNATIONAL ORGANIZATION FOR STANDARDIZATION ORGANISATION INTERNATIONALE DE NORMALISATION MEKAYHAPOAHAH OPFAHM3ALMR OCTAHAAPTW3AUWM Aerospace -- Pipelines - Identification Aeronautique et espace -- Tuyauteries -- Identification Referencenumber permitted without license from IHS ISO 12: 1987 (E) hTTOO EO6TSh 12~87 Foreword Iso (the International Organization for Standardization) is a worldwide federation of national standards bodies (Iso member bodies). The work of preparing International Standards is normally carried out through Iso technical committees. Each member bodyinterested in a subjectforwhichatechnicalcommittee has beenestablished has the right to be represented on that committee, International organizations, govern- mental and non-governmental, in liaison with Iso, also take part in the work. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the Iso Council. They are approved in accordance with IsO procedures requiring at least 75 % approval by the member bodies voting. International Standard ISO 12 was prepared by Technical Committee ISO/TC 20, Aircraft and space vehicles. This second edition cancels and replaces the first edition(IsO 12 :1976),which has beentechnicallyrevisedasfollows: the scope and field of application has been modified; sub-clause3.3(now4.3)on,thesupplementaryidentificationmarkerhasbeen expanded. Users should note that all International Standards undergo revision from time to time and that any reference made herein to any other International Standard implies its latest edition,unless otherwise stated. @ International Organization for Standardization, 1987 4851903 12-87 bhT6To0 8 INTERNATIONAL STANDARD ISO 12 : 1987 (E) Aerospace -- Pipelines -- Identification Scope and field of application 3.2 Basic identification This International Standard lays down the requirements for a scheme to indicate, by appropriate marking, the functions or 3.2.1 Each rigid pipe in the pipe systems listed in table 1 shall be identified by a marker bearing the designation of the system, contentsof rigid pipe assembliesin aircraft and spacecraft systems, but excluding those in aero-engines with the excep- togetherwiththe appropriatesymbol as described intable1 and shown in figure 2. tion of thosewhich connect directlytothe airframe systemsat their break points. 3.2.2Pipelinesforreplenishment,vents,pressuretransmis These requirements may also be applied to hose assemblies, if sion, priming and drains, or related functional equipment, shall desired. be identified by the same marker as the main pipeline. The purpose of the scheme is to provide the minimum iden- tificationnecessaryfornormal maintenancepurposes. Table 1 - Pipe systems and symbols NOTE - Markers used for the purpose of applying this identification Symbol (see figure 2) scheme should not adversely affect the chemical ormechanical proper- Designation ties of the pipes or'conduits. ofpipesystem Description No. Air conditioning (including Dotpattern 11 cabin pressurizing) 2 Reference Battery activator Ellipse with radiating tines 24 Breathing oxygen Rectangle 10 ISO3323,Aircraft- Hydrauliccomponents -Markingto Compressed gas Broad diagonal stripe 16 indicate fluid for which component is approved. Coolant Broad undulations 9 De-icing Triangle 11 13 3 Identification scheme Drinking water "H20" 25 Electrical conduit Flash of lightning 17 Filtered air "NBC" 27 3.1 General Fire protection Horizontal diamond 12 Fuel Four-pointed star 1 3.1.1 Where ambient temperatures permit, the scheme shali Hydraulic Circle 6 consist of markers fixed to the pipelines to indicate their func- Inerting Pipe cross1) 19 tions or contents, to give due warning where the contents are dangerous and,when required, to indicate the direction of flow Instrument air Zig-zag line 2) 8 of the