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  1. NickClark

    Partial Penetration and Full Penetration Joints on Lift Padeyes

    Thanks for the correction ak762. I am thinking of 2.7-3 which allows fillet welds in shear if I read correctly. If you can't modify the design but need to meet the dnv then your a bit stuck. I still don't know the code you need to meet or the eye design but I was speculating that you could...
  2. NickClark

    Partial Penetration and Full Penetration Joints on Lift Padeyes

    Which DNV code? 2.7-1 doesn't mandate full pen. But its a good idea from an NDT perspective. Can you modify the design to set in the pad eye? Nick
  3. NickClark

    low ferrite in weld of Duplex steel

    The responses are getting a little confusing. Duplex steels solidify as 100℅ferrite the transform partially to austenite on cooling based on two things. 1- cooling rate and 2- proportion of austenite forming elements. If your ferrite is too low you either need to reduce Ni or N etc or increase...
  4. NickClark

    Red Rust on 316

    Is this a form of the ferroxyl test used for plating porosity? Its common to use copper sulphate also which will plate out copper as a test for steel or stainless. Nick
  5. NickClark

    low ferrite in weld of Duplex steel

    The overmatched chemistry of 2209 is designed to produce 35-65 without any pwht. Its rare to pwht duplex welds in my experience. Maybe the increase in austenite forming elements in the weld metal is promoting transformation more than expected. Its also possible you have Nitrogen pick up if you...
  6. NickClark

    thermal expansion of carbon steel at temperature

    Vacuum brazing companies use graphite plates and jigs to support parts.its dimensionally stable and won't react.
  7. NickClark

    CuBe Spring Peening

    I don't see why not. Try AMS13165 or 2340 and metal improvement company. The fatigue benefits will vary from one material to another.
  8. NickClark

    Stainless and carbon steel fittings being used together

    Like Ed said passivate the parts. Or pickle and passivate if its serious contamination. It gets done all of the time either as a clean up or as a precaution. I expect a local plating shop which services the aero or oil industry will be able to process in bulk. After treatment you could prove its...
  9. NickClark

    WPS & PQR

    I think Alok is asking if the fabricator can use a previously qualified wps for the new job. Providing that the fabricator doing the work performed/owned the previous qualification then yes they can user it within the allowable range of their qualification. Note that this assumes you have no...
  10. NickClark

    2205 Welding to Shell DEP

    Everyone is focusing on G48 but that doesn't appear to be your problem. Although I'm supposed that your passing the G48 with a lack of root fusion as I we could expect this to cause a crevice failure. Can you describe the root gap used and backing gas (mix and Max o2 content). Unless you use a...
  11. NickClark

    ASME Roll Threading Specification

    There is a military spec which I think includes some guidance. I think its ff-s-86. The fastener manufacturers often follow it. Check the sps group website data sheets for socket head caps
  12. NickClark

    cathodic protection of steel tube flying leads

    Thanks Steve I know the paper. And sorry for the earlier confusion!
  13. NickClark

    Stainless Bolting

    ISO3506 A4-70 or 80.
  14. NickClark

    Duplex crevice corrosion

    A well designed CP system will prevent and galvanic and crevice corrosion in any connected materials. For duplex steels follow DNV-RP-F112 Guidelines and you should be OK. This is a bit of a generalisation but if it weren't close to the truth we would have big issues with all installed subsea...
  15. NickClark

    Coating of steel in a CP ennironment

    For long term subsea service you will no doubt have cathodic protection. In this case and due to the function you may have to leave the surfaces bare. As Steve suggests you can consider stainless steels/CRA's if the parts are shielded or isolated from the cp System. Note that bare steel and bare...
  16. NickClark

    Cathodic protection for equipment periodically submerged

    The cost of sacrificial anode cp may not be significant. It all depends on the size of the structure you need to protect. If its small and you use the coating you have specified then it may simply be enough to attach one anode. ( obviously you will need to run the calcs to dnv-rp-b401 or...
  17. NickClark

    cathodic protection of steel tube flying leads

    Steve sorry I thought I clarified. Water temp is up to 30 degrees c. Note your recommendation thanks Nick
  18. NickClark

    cathodic protection of steel tube flying leads

    As good a spec as it is this is one of those occasions when I'm not prepared to trust eemua. There are too many papers and standards that conflict. The words strictly and typically suggest ( of course) that its not always the case. Thanks for the replies Nick
  19. NickClark

    cathodic protection of steel tube flying leads

    Sorry. I'm getting confused between two issues. Then what about at 25-30 degree water temperature?
  20. NickClark

    cathodic protection of steel tube flying leads

    5 degree water temperature and fluid temperature. No internal corrosion issue with 316 and we don't need the tensile strength. The only logical reason for choosing 25Cr was for external seawater resistance. I.e. the CP won't throw. Maybe the first post has it that simply its belt and braces...
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