The performance does not meet the standards, but the owner agrees to use it – can it still be accepted?
Thread Content
Our factory has a pressure vessel with high pressure; the fluid contained within it is not flammable or explosive, being a rather ordinary liquid. Therefore, it is not governed by the regulations for fixed-pressure vessels. Nevertheless, its design and manufacturing follow JB4732 standards. An agreement was reached with the client during contract signing, and the vessel is designed in accordance with the relevant vessel design standards, ensuring compliance with requirements outlined in the regulations for fixed-pressure vessels, JB4732, NBT47008, etc. However, during the manufacturing process, the impact energy of one of the larger forgings did not meet the requirements specified in standard NBT47008 – it was slightly short (by 2 J) and therefore unusable. Given the tight deadline and the owner’s urgent need for the equipment, they suggested that we use it and agreed to accept it. Is that acceptable? If the performance does not meet the standard requirements, does the owner still have the right to approve its use? Is it illegal for our factory to use it? If something goes wrong, will it be investigated? What responsibilities will I have to bear?
31J is the requirement for 16Mn forgings in JB4726; the new standard raises this value to 34J, which can serve as a theoretical basis for you. It’s not that much of a difference; it’s fine, go ahead and use it. If you are not confident, you can request tests for the chemical composition, other mechanical properties, UT, etc. If the values for these other parameters deviate significantly, you can refuse to proceed at that time. :)
Enterprises are the primary holders of safety responsibilities and are accountable to themselves.
It’s not 16Mn; it’s a forged part containing Mn and Mo. It’s relatively heavy, difficult to purchase, and has a long production cycle. Except that the individual and average impact energy values do not meet the requirements, all other chemical compositions, tensile properties, metallographic characteristics, and flaw detection results are satisfactory. Also, we are a container manufacturer; we purchase the forgings ourselves. When the end-users are aware of this, they tend to prefer using these forgings. However, we’re not sure ourselves and don’t know whether we can use them or not.
No retest? If it fails the retest as well, then… You need to have the owner sign their approval for its use
If the owner signs, can it be used? Dare you use it? Is our manufacturing plant responsible if something goes wrong?
Our opinion leans towards doing it again or finding another solution, but the owner prefers to use it as is.
If money and time aren’t a concern, just do it
Just by doing it one more time, will it definitely be qualified?