Not sure, but are you inquiring about methods to perform condition assessments for in-service process pipes?
If so, this can be performed. There are various technical articles on the internet and nondestructive testing (NDT) web sites that you can review that would provide basic information regarding condition assessment methodology. Typically from my experience, you have 3 levels of assessment – Level I begins with a review of the piping system past and present operating conditions, problems and materials of construction. Level II assessment would be NDT based on the Level I assessment results. The NDT would be performed by a qualified organization.
Based on the Level I and Level II assessment results, the Level III assessment usually involves removal of material samples that are subjected to laboratory analysis or creep testing to evaluate remaining service life of the process pipe.