The vendor is responsible of the quality of its products. He should provide you with a certificate, data report, stamping ect., that assure you that all the rules were followed. So I think you only need to do a general visual inspection upon arrival of vessels and inspect for damage that could...
Derek,
If you are referring to incomplete joint penetration it may not be a defect as this nozzle weld could have been designed that way. Nozzle welded only from one side is allowed per ASME sect.8 under some conditions. It is not be the best practice but it is allowed.
You should look for...
Preheat is also important to remove humidity from the base metal that could bring hydrogen in welded areas. Slow cooling rate also allows for dissolved hydrogen to get out of the weld. Hydrogen in welds causes cold cracking.
I will try to clear things up. Test requirements for a reparation is often misunderstood.
Duwe6, a hydro test ,as per ASME sect. VII, of a repaired item is never required nor is it allowed. What the NBIC part 3 call for is a leak test and that is mandatory for any repairs on the pressure...
If I understand well your question, you have found, by calculation, the minimum wall thickness required for a given application and you want to know what nominal thickness plate to order.
Mill under-tolerance for plate is no more then 6%. So add that to your minimum thickness and see what is...
Just some thoughts.
I would verify if this repair is required to be done according to original code of construction or current code.
If current code is use, design formulas may have changed from the original construction and that would require re-calculations.
In general, codes have evolved...
Ultrasound testing of welds in 8 mm thick material is feasible. However, duplex steel grain structure of weld HAZ is more of a challenge for UT. Maybe a highly qualified technician could come up with a reliable test procedure.
I think the correct term to use here is brazing. In this case, welding is impossible for such dissimilar materials.
HAZ cracking is usually not a problem with brazing.
More details please.
I concur with the above posts. Moreover, I think lowering the MAWP on a pressure vessel is seen as a Alteration in most jurisdiction. So you have to deal with them anyway.
andrenov,
I think you should not hydrotest unless a repair was done. There are other ways to find leaks.
The NBIC is the reference for in-service boilers and vessels. It gives guidance and rules for hydrotest of repaired items. You should also look in the Part 2 ,that covers inspection, and...
It is called contamination of stainless steel by free iron.
Chemical treatment exist to avoid any problem after fabrication, it is called passivation.
Look that up:
http://www.stainlessfoundry.com/FreeIron.asp
TJOrlowski,
What is the point in spot radiography of a seamless pipe?
UW-11(a)(5)(b) applies to category B and C joints that intersect a seamless section. Not to that seamless section itself.
I think as per ASME sect.II part D stress value tables, E=1 for seamless pipes and it depends on what...
