ISO 12944 a global corrosion standard Delivering Solutions through Global Experience
Introduction ISO 12944 Paints & Varnishes - Corrosion Protection of Steel Structures by protective paint systems (parts 1-8) (1998) The ISO 12944 standard is intended to assist engineers and corrosion experts in adopting best practice in corrosion protection of structural steel at new construction. ISO 12944 is progressively superseding regional standards to become a truly global benchmark in corrosion control.
Step 1 - Select the corrosive environment Use the following table to select the most appropriate classification: ISO 12944 Classification
Typical Environments
C1 C2
Rural areas, low pollution. Heated buildings/neutral atmosphere.
C3
Urban and industrial atmospheres. Moderate sulphur dioxide levels. Production areas with high humidity.
C4
Industrial and coastal. Chemical processing plants.
C5I
Industrial areas with high humidity and aggressive atmospheres.
C5M
Marine, offshore*, estuaries, coastal areas with high salinity.
* Corrosion protection in ISO 12944 C5M - Offshore environments is being addressed via a new standard (ISO 20340) dedicated to this environment
These environments are based on experiments that have measured the rate of metal loss for uncoated steel. The classification of environments applies to structural steel exposed to ambient (less than 120°C/248°F) conditions. Stadium - City locations could be classified as ISO 12944 C3
Why specify ISO 12944 Coating Systems? ISO (www.iso.org) is a recognised and widely adopted standards organisation, that assists in providing best practice throughout industry. Selecting specifications that comply with ISO 12944 provides you with:
• • • • •
Confidence that the corrosion protection you specify will be fit for purpose An objective approach to coating selection A simplified matrix of coating systems to select from A meaningful coating design life A universally accepted standard
Airports - The inside of a heated building is typically an ISO 12944 C2 environment
Step 2 - Decide on the design life (durability) of the coating system
•
ISO 12944 Durability Ranges (time to first major maintenance) High Durability
>15 years design life
Medium Durability
5-15 years design life
Low Durability
•
<5 years design life
This table should be used to select the most cost effective system for the required project lifetime. It should be noted however that durability does not equate to a guarantee time - it is more appropriate to equate durability to the "Design Life" of the coating system - regular minor maintenance should always be anticipated, in order to achieve the required life to first major maintenance.
Power Plant - A typical ISO 12944 C4 environment
Our Commitment “International Protective Coatings operate across the globe to the same high standards. We can offer ISO 12944 compliant coating specifications for structural steel; tested, manufactured and supplied under the same rigorous standards in over 50 countries.” Specify with confidence, specify ISO 12944 Regular inspection and routine maintenance via our Interplan service will assist in achieving the required design life for the coating system.
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Step 3 - Select an ISO 12944 compliant system
•
The coating systems described in this brochure have been evaluated against ISO and ASTM test standards and self certified to ISO 12944 part 6. ISO 12944 Environment Design Life/Durability <5 years Design Life/Durability 5-15 years
Design Life/Durability >15 years
C1
A
A
A
C2
A
B
B
C3
B
B
C4
#
C
C5I
#
E
C
D
D
E
F
H
G
H
Note: ISO 12944 C5M (Offshore Environments) have been partly superseded with ISO 20340 and hence are not included in this table. # International Protective Coatings does not routinely recommend systems for Design Lives <5 years in C4 or C5 environments.
Reference
Isocyanate Free (3)
System VOC
@ 75 µm
Yes
<40g/m2
@ 150 µm
Yes
<70g/m2
Coating System
A
Interlac 789 o r Intergard 345
B
Intergard 345
C
Intercure 200HS Interthane 990 (2)
@ 150 µm @ 50 µm
D
Intercure 200HS Interfine 878
@ 150 µm @ 50 µm
E
Interzinc 52 Intergard 475HS Interthane 990 (2)
@ 75 µm @ 150 µm @ 50 µm
F
Intercure 200HS Interfine 878
@ 200 µm @ 75 µm
G
Interzinc 52 Intergard 475HS Interthane 990 (2)
@ 75 µm @ 175 µm @ 50 µm
H
Interzinc 52 Interfine 979
@ 75 µm @ 125 µm
(1)
No
(6)
Yes
No
(6)
Yes
No
(6)
Yes
<80g/m2
Aesthetic Durability (4)
Corrosion Resistance (5)
(1)
(6)
<60g/m2
<110g/m2
(6)
<80g/m2
<120g/m2
(6)
<80g/m2
(1) Durability (gloss and colour retention) when exposed to sunlight can be significantly improved by top coating this specification with Interthane 990 @ 50 µm. In these instances it is possible to reduce the thickness of Intergard 345 by 25-50 µm to 100-125 µm. (2) Interthane 990 is a high gloss finish - if a semi gloss finish is required it can be replaced by Interthane 870 specified at 100 µm. In this instance the previous coat can be reduced by 50 µm in order to achieve the same total dry film thickness. (3) Isocyanate containing coatings have known H&S issues during application. Interfine coatings are isocyanate free. (4) Aesthetic durability is a measure of gloss and colour retention. These results are based on ISO and ASTM testing carried out in an ISO9001 certified laboratory. (5) Corrosion resistance is a measure of the corrosion performance. These results are based on ISO and ASTM testing carried out in an ISO9001 certified laboratory. (6) Replacement of Interthane 990 with Interfine 878 allows for durability to be significantly increased (to 5 ) and an isocyanate free finish to be utilised. For further advice and an interactive ISO 12944 specification guide visit:
, International and all product names mentioned in this publication are trademarks of, or licensed to, Akzo Nobel. © AKZO NOBEL 2004 Unless otherwise agreed by us in writing, any contract to purchase products referred to in this brochure and any advice which we give in connection with the supply of products are subject to our standard conditions of sale.
G4_ISO_UK 10/04
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