Welding over porosity
Welding over porosity
(OP)
We are building a API 650 tank and the production guys are welding over porosity saying it's ok and it will burn out. What does the code say about this or if not what can happen by doing this?
They are also gouging the backside and then with all the nonfusion present after gouging they are welding over that as well..
They are also gouging the backside and then with all the nonfusion present after gouging they are welding over that as well..





RE: Welding over porosity
Worst case is failed NDE and/or leaks.
RE: Welding over porosity
Take a few radiographs and compare them to what's allowable in API 650. Normally you would tell the inspection company to what code or standard you want weld graded to and let them give you a starting point.
Can you come back with some dimensions of the tank.
Weld details, electrode and thickness and especially what code are the welders qualified to.
In my 40+ years around welders the most common refrain is "I'll float it out".
RE: Welding over porosity
RE: Welding over porosity
Porosity does not just magically disappear or "burn out" with carbon steel. If NDE is performed, they WILL end up cutting the entire thing out and rewelding it anyways. In addition to porosity, gouging and welding over unfused material is just begging for that seam to crack. If a full penetration weld is require, the inspector can reject the entire seam based on that criteria alone.
RE: Welding over porosity
This is a violation using either API or NBIC codes and standards. Nowhere in recognized codes and standards is it permitted to weld over defects.
RE: Welding over porosity
RE: Welding over porosity
The items in 7.4.1 and 7.4.2 would apply to finished welds, but I don't believe they would be applied to intermediate passes of a weld. Not to say it would be acceptable, but the determinant would be the testing of the finished weld, not the appearance of intermediate passes.
"with all the nonfusion present after gouging"- what nonfusion is present after gouging? Is this the porosity again, or a different issue?