STEEL TUBE AND PIPE HANDBOOK - February 2012

3 Committee for standardization and standard International, worldwide recognized actual standards are issuedby two standardization institutions resident in Geneva: ISO (International Standards Organization) – issu- ing universal standards IEC (International Electrotechnical Commision) – is- suing electrotechnic standards ISO standards are accepted worldwide and therefore they usu- ally do not go trough the national standard systems. For steel tube they are applied rarely. ISO numbers are in brackets. European standardization European standardization is analogous to global system, but it con- sist of three committees. Two first resident in Brusel, the third one in Sophia Antipolis (France): CEN (Comité Européen de Normalisation) – issues universal standards. Standards regarding iron and steel are isuued by European Commision for Standardization of Iron and Steel (ECISS) and appropriate Technical Committees. CENELEC (Comité Européen de Normalisation Élec- trotechnique) – issues electrotechnic standards ETSI (European Telecomunications Standards Insti- tute) – issues telecommunication standards National committee for standardization They issue national standards. Connecting to European Union enlarging are European standards (EN) implemented into the national standard systems (technical standard harmonization). Unlike ISO standards are EN implemented without modification and hereby all discordant national standards have to be can- celled. Connected with this the philosophy of standard use has essentially changed: in the past was performance of standard regulations obligatory. At present appear two terms: relevance and obligation of standard. The standard is valid but, except some clauses, its observance is not compulsory. Standard gives recom- mend technical terms, wich need not be applied. On the other hand two factors arise: • if the standard is specific in the contract between seller and buyer, it will become a part of contract and all its demands have to be executed • in the case some damage occures in consequence of failure of harmonized standard claims, he who failed terms, defined by gowernment act, bear liability. That’s because by law if national standard system assumes harmonized EN, it will be- come also harmonized. After publishing in Official publica- tion of national standards standard may be used for advise- ment of technical terms execution. Another standards Here belong mainly company standards. These can not be con- trary to national standards. Further class are the standards of craft companies, e.g. in USA (AISI, ASTM, ASME, API, SAE). Valid bilateral technical terms or specifications can be shut-down between commercial partners. Technical standards are a part of legislation valid in appropriate industrial field. Specific connection of particular regulations is shown in the capters of individual tube range. Steel tubes – classification and terminology Mentioned terms of steel tubes are in standard EN10079 or others (ISO6929). Tube classification goes out several aspects: mode of produc- tion, cross section shape, tube ends treatment, sphere of tube usage. According to EN10079 tubes rank among so-called long prod- ucts. It is a product having permanent circular or another hollow section along, with both ends free and with relatively long length. By mode of production are tubes divided to two big groups – seamless and welded. Each of this groups can be sectional- ized by method of tube production – hot or cold production. A part of tube products are also so-called hollow sections . Here belong seamless or welded tubes of circular, square or rectangular section, used as part of building steel constructions or machine units. Hollow bars are seamless tubes of circular section designed for production of machine parts by machining. Different from the two first tube groups hollow bars have qualitative and di- mensional parameters, which fit to requirements of workability, heat treatment or surface quality. Tubes in this guide book are ordered by application consider- ing mode of production, similar to ordering in new steel tube EN. Technical standards of steel tubes Technical characteristics of steel tubes are detailed in the appro- priate technical standards. Pipe parameters could be divided into three main groups: • dimensions and their tolerances (depending upon the tube manufacturing method) • steel grade and steel conditions • technical delivery conditions Individual national bureaus of standards use different procedures for data standardization of steel pipes. In real life three options are used: • each main group of parameters is contained in a single stan- dard. The standards are interconnected using references to the related ones. Dimensional standard contains dimensional tables and their tolerances; steel standard contains its chemical compo- sition and mechanical properties for various methods of pipe manufacturing and steel tempers. The third standard of the tech- nical delivery conditions (TDC) sets out all remaining require- ments for pipes – testing, acceptance, certificates, packaging, marking, etc. At the same time it contains references to other standards where these activities are described (e.g. STN, ČSN). • the second option is when steel and its characteristics are included into the TDC standard, and this one contains dimen- sional tolerances. Two standards are used to describe a pipe – dimensional standard that contains dimensional table and the TDC standard (e.g. DIN). • the third option – pipe parameters are in a single standard, which also contains the dimensional table, or extraction from the general table of dimensions constituting which is the con- tent of the general dimensional standard (e.g. NFA, EN). In real life there are cases, where both the seller and the buyer make bilateral TDC contracts, or they deliver pipes in accor- dance with the buyer’s specifications, which can also include the references to national standards. Normally, this is the case, where the demands for pipes are higher then those set-up in the national standards.