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  1. DefenderJ

    Sample preparation guidelines for Vickers hardness testing of weldments

    Thanks for the further comments. Lack of procedure for preparation is an obvious area for inconsistency. We have decided to eliminate differences in machining practices by doing an initial hand grinding on a 60 grit Zirmet grinding paper (with water) to remove approx 0.2mm of material. Zirmet...
  2. DefenderJ

    Sample preparation guidelines for Vickers hardness testing of weldments

    Thank you both for your input, it is very helpful to get some opinion as I have not been able to find much literature on this. I will develop procedures for the test houses we use for our work - concentrating on the initial "heavy" preparation. This way we should be able to get consistent...
  3. DefenderJ

    Sample preparation guidelines for Vickers hardness testing of weldments

    In the testing of weld hardness for welding procedure qualification I find that I am concerned over the preparation route which may be affecting the values I am getting. As the hardness limit is 250HV10 (sour service applications) and materials are strong we are often working close to the limit...
  4. DefenderJ

    CR4 and EN 43 A... how different are they?

    Hi Elastomatt. In simple terms they are not that similar when you look at composition, mechanical properties etc. Grade 43A is an old designation - it is most likely to be EN 10025 S275JR, it is hot rolled, general purpose, weldable steel of 275MPa min yield The CR4 is a cold rolled steel with...
  5. DefenderJ

    Requirement to pressure test process vessels during service life?

    This thread is running so fast I can't keep up. Thanks for the input everyone. The position I am in is that we currently have exceedingly little proof of vessel condition. We do not appear to require any more than we currently have with a insurance inspector inspection. A hydrotest would be...
  6. DefenderJ

    Requirement to pressure test process vessels during service life?

    Thanks Steve. This is useful - the HSE does have some good stuff. I see a lot of this report is based around RBI and is more about inspection that hydrotest. A hydrotest would actually being easier and quicker than NDE for us. Before RBI are there any guidelines that might be applicable?
  7. DefenderJ

    Requirement to pressure test process vessels during service life?

    We have a number of ASME VIII Div1 pressure vessels that have seen 28 years service. Fabricated from ASTM A516 Gr 70. Also several possible degradation mechanisms. Some of these have been hydrostatically tested after modifications. However there are several that have had no test since...
  8. DefenderJ

    Deep corrosion pits on outside of carbon steel piping

    StoneCold Thanks for your input. We burn Heavy Fuel Oil on site for boilers and calciners. We also have two power stations down the river from us one on coal the other also on HFO. We have speculated that there might be something like this on a tank roof that was close to our stacks. What do...
  9. DefenderJ

    Deep corrosion pits on outside of carbon steel piping

    Thanks everyone for the input. Metengr - it's useful to know someone else has seen it. I'm still trying to work out where the deposit comes from. Stanweld - this is not corrosion under insualtion (CUI) - we have plent of that as well! This problem occurs on uninsulated steel. often...
  10. DefenderJ

    Deep corrosion pits on outside of carbon steel piping

    We have a lot of unpainted carbon steel pipes on our plant which are outdoors. I am increasingly seeing an unusual corrosion on the outside of the pipe which penetrates deep into the pipe and can lead to leakage. The "pit" is faily wide and filled with dense corrosion product - generally dark in...
  11. DefenderJ

    Request on facts and figures regarding MIC in water stagnant systems

    We have practical experience of MIC on our combined fire protection and potable water system, circa 30 years old. Our plant is in Ireland so ambient temperatures typically range from 0-20°C. The piping system is not buried, but on raised supports about 8m high We get leaks from MIC in ASTM...
  12. DefenderJ

    Controlling Pipe Dimensional Quality

    Thanks yet again to everyone for your excellent input on this. I have decided to try the following approach in our bid request package: 1. Western European mills only unless the supplier carries out their own independent verification – chemistry, mechanical and dimensional tests 2. We will...
  13. DefenderJ

    Controlling Pipe Dimensional Quality

    Thank you everyone for your input. We do not buy direct from the mills and we don't have the resources to inspect at the mill or audit the mills ahead of production. I would agree to audit the mill and inspect the product would be the way to go if we could. Rejecting material when it is...
  14. DefenderJ

    Controlling Pipe Dimensional Quality

    We use API5L Gr.B and ASTM A106 Gr.B piping. Recently we have had quality issues; one batch of pipe had ends that were not cut square; another batch had eccentric OD and ID resulting in wall thickness below the minimum in one position. Dimensional issues make fitting more difficult and can...
  15. DefenderJ

    Alloy 625 welding procedure test failure

    Weldtek, Westbrook are "repackagers", as you suspected. I think I'll stick with the better known companies in future, such as Special Metals. I spoke to the special metals technical department who were very helpful - they didn't have a direct answer but gave me a lead to someone else. This...
  16. DefenderJ

    Alloy 625 welding procedure test failure

    Weldtek - thanks for that advice, I will speak to them. (the consumable used was from Westbrook welding alloys) Metengr - it is an expansion bellows weld on a heat exchanger (replacement bellows), so it is part of the pressure boundary. I have also been advised to selectively choose a batch...
  17. DefenderJ

    Alloy 625 welding procedure test failure

    Metengr, Thanks again for your help with this. Regarding finding out whether the code prohibits this approach - can you provide guidance on where to look in ASME VIII?
  18. DefenderJ

    Alloy 625 welding procedure test failure

    Metengr, Thank you for your reply. I had referred to QW153. I saw that QW153.1(c) may be applicable. However, I was thrown by the use of "applicable section allows". Please could you explain a little further how I can use this to validate my procedure? Also, for the minimum specified UTS...
  19. DefenderJ

    Alloy 625 welding procedure test failure

    I have run a welding procedure test to ASME IX. Details: 2" sch 40 pipe butt weld with GTAW using an alloy 625 filler wire. 5G positon, max interpass 150°C It has failed the tensile test: failure in weld metal - values 750 to 800 MPa. The parent material Alloy 625 grade 2(SB-444) is...
  20. DefenderJ

    As rolled steel vs normalised

    Thanks metengr. Have reviewed min design temperature and decided to specify normalised grades.

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