Visual inspection for piping


I am a beginer, I would like to learn visual inspection.
Could anybody guide to visual inspection for piping? how to check a weld?

Many thanks.

Follow welding instruction in my blog.
There are included before welding / during welding and after welding.

How to accept or reject that based on project specification or acceptance criteria.

Common standard application:

  • For structural steel: AWS D1.1, D1.2 or D1.6 …
  • For piping: ASME B31.3, B31.1, ASME V, VIII div. 1 …
  • For linepipe: API 1104.