High Strength Bolts
These have been used in both the Medupi Power Station and Kusile Power Station.
These solutions utilize different systems (HR and HV) of bolt/nut/washer assemblies. Both systems are well proved and it is up to the experts responsible for structural bolting whether they use the one or the other system.
Bolt/nut/washer assembly System HR |
Bolt/nut/washer assembly System HV |
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General requirements |
EN 14399-3 |
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Bolt/nut assembly |
EN 14399-3 |
EN 14399-4 |
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Marking |
HR |
HV |
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Washer (s) |
8.8/8 |
10.9/10 |
10.9/10 |
Suitability test for pre-loading |
EN 14399-2 |
EN 14399-2 |
Bolt/nut/washer assembly System HR:
- General requirements: EN 14399-3
- Bolt/nut assembly: EN 14399-3
- Marking: HR
- Washer (s): 8.8/8 or 10.9/10
- Suitability test for pre-loading: EN 14399-2
Bolt/nut/washer assembly System HV:
- General requirements: EN 14399-3
- Bolt/nut assembly: EN 14399-4
- Marking: HV
- Washer (s): 10.9/10
- Suitability test for pre-loading: EN 14399-2
Pre-loaded bolted assemblies are very sensitive to differences in manufacture and lubrication. Therefore it is important that the assembly is supplied by one manufacturer who is always responsible for the function of the assembly.
Equipment has been brought into the country to do the assembly test and Fbi Max.