Dear All,
Can anyone answer my below query.

A valve made of SA 352 LCB for low temperature service. Theoritically Impact tested and absorbed energy shall be 18 Joule.

But after hydrotest and painting, valve has been exploded and a test specimen was cut from the body and tested for Impact testing, but resulted that absorbed energy is very less(1/3rd of theoritical).

What is the reason for this.

Any guideline for impact testing after farication of an item.

Anyone answer my query please.