6552 nternational Standard (ISO INTERNATIONAL ORGANIZATION FOR STANDARDIZATION MEXAYHAPOAHAA OPTAHM3ALMA NO CTAHAAPTW3AWW+ORGANISATION INTERNATIONALE DE NO RMALISATION Automatic steam traps -- Definition of technical terms Purgeurs automatiques de vapeur d'eau - Definition des termes techniques First edition 1980-08-01 UDC 621.186.6 : 001.4 Ref. No. 1SO 6552-1980 (E) 552-1980 Descriptors : industrial valves, traps, steam, dimensions, temperature, flow rate, symbols, definitions. Not for Resale Price based on 3 pages Foreword IsO (the International Organization for Standardization) is a worldwidefederation of national standards institutes (iso member bodies).The work of developing Inter- national Standards is carried out through IsoO technical committees. Every member body interested in a subject for which a technical committee has been set up has the right to be represented on that committee. International organizations, governmental 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. International Standard ISO 6552 was developed by Technical Committee ISO/TC 153. General purpose industrial valves, and was circulated to the member bodies in March 1979. It has been approved by the member bodies of the following countries : Australia Germany, F.R. Poland Austria India Romania Belgium Italy Sweden Canada ueder Switzerland Chile Korea, Rep. of United Kingdom Denmark Libyan Arab Jamahiriya USA Finland Netherlands USSR France Norway The member bodies of the following countries expressed disapproval of the document on technical grounds : Czechoslovakia South Africa, Rep. of @International Organization for Standardization, 1980 Printed inSwitzerland Not fr Resale ISO 6552-1980 (E) INTERNATIONAL STANDARD Automatic steam traps -- Definition of technical terms Introduction 1 Scope and field of application The purpose of this International Standard is to establish This International Standard gives the definitions of the major precise definitions for technical terms and expressions which technical termsand expressions usedtodescribean automatic are commonly used to describe with a certain accuracy an steamtrapasfarasdimension,pressure,temperatureandflow automatic steam trap under operating conditions. rate are concerned, as well as their corresponding symbols and units. This International Standard has to be considered in conjunction with every other International Standard using these terms and 2 Definition of technical terms expressions to describe the technical characteristics or perfor- mances of an automatic steam trap. 2.1 Dimension Term Symbol un Definition Nominal size DN Numerical designation of size which is common to all com- ponents in a piping system other than components designated by outside diameters. It is a convenient round number for ref- erence purposes and is only loosely related to manufacturing dimensions, In any case, the nominal size DN cannot be subject to measure- ment and shall not be used for purposes of calculation: e with ISC No reproductionor networking pemited without license from IHS Not fr Resale 1