Witness UFD of weld overlayed valve to check for dis-bonding 1

[kpm21443]

What is the meaning of the below statement. How should the UFD be done.

Witness UFD (Ultrasonic Flaw Detection)of weld overlayed valve to check for dis-bonding.

 

[hsbcn]

UFD is an NDE that checks for cracks and fissures by propagating sound waves through solid material. The NDE is carried out using a quite simple electronic device.

High-alloy valves for corrosive petrochemical applications.