EN 12502-4:2004

Protection of metallic materials against corrosion - Guidance on the assessment of corrosion likelihood in water distribution and storage systems - Part 4: Influencing factors for stainless steels

This document gives a review of influencing factors of the corrosion likelihood of stainless steels used as tubes, tanks and equipment in water distribution and storage systems as defined in EN 12502-1.

Korrosionsschutz metallischer Werkstoffe - Hinweise zur Abschätzung der Korrosionswahrscheinlichkeit in Wasserverteilungs- und speichersystemen - Teil 4: Einflussfaktoren für nichtrostende Stähle

Dieses Dokument enthält eine Übersicht der Einflussfaktoren für die Korrosionswahrscheinlichkeit von Rohren, Behältern und Zubehörteilen, die aus Kupfer und Kupferlegierungen hergestellt sind, in Wasserverteilungs- und -speichersystemen, wie sie in prEN 12502-1 definiert sind.

Protection des matériaux métalliques contre la corrosion - Recommandations pour l'évaluation du risque de corrosion dans les installations de distribution et de stockage d'eau - Partie 4 : Facteurs à considérer pour les aciers inoxydables

Le présent document étudie les facteurs d'influence du risque de corrosion des aciers inoxydables utilisés sous forme de tubes, réservoirs et équipements dans les installations de distribution et de stockage d'eau tels que définis dans le prEN 12502-1.

Protikorozijska zaščita kovinskih materialov - Navodilo za ocenjevanje verjetnosti nastanka korozije v porazdeljeni vodi in skladiščnih sistemih - 4. del: Vplivni dejavniki za nerjavna jekla

General Information

• Status: Published
• Publication Date: 21-Dec-2004
• Withdrawal Date: 29-Jun-2005
• ICS: 23.040.99 - Other pipeline components
• ICS: 77.060 - Corrosion of metals
• ICS: 91.140.60 - Water supply systems
• Technical Committee: CEN/TC 262 - Metallic and other inorganic coatings
• Drafting Committee: CEN/TC 262/WG 10 - Corrosion likelihood
• Current Stage: 9093 - Decision to confirm - Review Enquiry
• Completion Date: 22-Jul-2020
• Ref Project: SIST EN 12502-4:2005 - Protection of metallic materials against corrosion - Guidance on the assessment of corrosion likelihood in water distribution and storage systems - Part 4: Influencing factors for stainless steels

Standards Content (Sample)

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Korrosionsschutz metallischer Werkstoffe - Hinweise zur Abschätzung der Korrosionswahrscheinlichkeit in Wasserverteilungs- und
speichersystemen - Teil 4: Einflussfaktoren für nichtrostende StähleProtection des matériaux métalliques contre la corrosion - Recommandations pour l'évaluation du risque de corrosion dans les installations de distribution et de stockage d'eau - Partie 4 : Facteurs a considérer pour les aciers inoxydablesProtection of metallic materials against corrosion - Guidance on the assessment of corrosion likelihood in water distribution and storage systems - Part 4: Influencing factors for stainless steels91.140.60Sistemi za oskrbo z vodoWater supply systems77.060Korozija kovinCorrosion of metals23.040.99Drugi sestavni deli za cevovodeOther pipeline componentsICS:Ta slovenski standard je istoveten z:EN 12502-4:2004SIST EN 12502-4:2005en01-marec-2005SIST EN 12502-4:2005SLOVENSKI
STANDARD
EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 12502-4December 2004ICS 77.060; 23.040.99; 91.140.60English versionProtection of metallic materials against corrosion - Guidance onthe assessment of corrosion likelihood in water distribution andstorage systems - Part 4: Influencing factors for stainless steelsProtection des matériaux métalliques contre la corrosion -Recommandations pour l'évaluation du risque de corrosiondans les installations de distribution et de stockage d'eau -Partie 4 : Facteurs à considérer pour les aciers inoxydablesKorrosionsschutz metallischer Werkstoffe - Hinweise zurAbschätzung der Korrosionswahrscheinlichkeit inWasserverteilungs- und
speichersystemen - Teil 4:Einflussfaktoren für nichtrostende StähleThis European Standard was approved by CEN on 22 November 2004.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Central Secretariat or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2004 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 12502-4:2004: ESIST EN 12502-4:2005

As a result of the complex interactions between the various influencing factors, the extent of corrosion can only be expressed in terms of likelihood. This document is a guidance document and does not set explicit rules for the use of stainless steels in water systems. It can be used to minimize the likelihood of corrosion damages occurring by:  assisting in designing, installing and operating systems from an anti-corrosion point of view;  evaluating the need for additional corrosion protection methods for a new or existing system;  assisting in failure analysis, when failures occur in order to prevent repeat failures occurring. However, a corrosion expert, or at least a person with technical training and experience in the corrosion field, is required to give an accurate assessment of corrosion likelihood or failure analysis. NOTE Stainless steels are used for domestic pipework, in the food industry and, more importantly, in the chemical industry covering a variety of aggressive environments and service conditions. This explains the existence of a significant number of steel grades each with specific corrosion resistance and also specific mechanical properties.
For the purposes of this document, the terms and definitions given in EN ISO 8044:1999 and EN 12502-1:2004 apply. 4 Materials For the purpose of this document, the term “stainless steel” includes all martensitic, ferritic, austenitic-ferritic and austenitic steels conforming to the requirements of EN 10088-1 [2], EN 10088-2 [3] and EN 10088-3 [4]. Examples of steel grades that are used or that can be considered as candidate materials for supply water installations are listed in EN 10312 [5]. This document also applies to stainless casting alloys, which are commonly used for the production of valves and fittings and which are of the same composition type as the steels listed in EN 10088, Parts 1 to 3. The casting alloys can be considered as equivalent to their wrought counter parts, provided that no sensitization of the material remains after manufacturing (to be checked by testing the resistance against intergranular corrosion). 5 Types of corrosion
5.1 General The most common types of corrosion are described in EN 12502-1:2004, Clause 4. The rate of uniform corrosion of stainless steels in water distribution and storage systems is negligible because of their passive state. Under the conditions prevailing in water systems stainless steels are usually the more noble materials and hence are not endangered by bimetallic corrosion. The likelihood of intergranular corrosion is negligible in the systems under consideration.
Discoloration of the material’s surface resulting from deposition of foreign corrosion products is not indicative of corrosion of the stainless steel. SIST EN 12502-4:2005

Sensitization can also lead to an increase in the likelihood of pitting corrosion. Incorrect heat treatment or welding procedures, where the material remains for a prolonged period of time in the temperature range of SIST EN 12502-4:2005

Sensitization can be revealed by testing in accordance with EN ISO 3651-2 [6]. Materials in the as-fabricated condition should be resistant to this test. Sensitization during fabrication and welding, especially with wall thicknesses greater than 6 mm, can be avoided by following the recommendations from the material’s manufacturer. 5.2.3 Influence of the characteristics of the water The likelihood of pitting corrosion of stainless steels increases as the chloride ion concentration in the water increases, if the other service conditions remain constant.
The likelihood of pitting corrosion (within the limits of supply water) is either decreased or the pitting corrosion is not influenced by the presence of other anions. The likelihood for pitting corrosion of non-molybdenum-bearing ferritic and austenitic stainless steels in cold water becomes high when the chloride ion concentration exceeds about 6 mmol/l. For hot water the limiting chloride ion concentration for these
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