I recently received a question from a client about “piping inspection methods for newly installed piping”. It seems that a general contractor was advising the facility that they were “required” to do some “thickness testing” on newly installed piping as part of the installation QA/QC. The PSE asked me “So are we required to take TML’s on newly installed piping?”
The short simple answer is NO, but as I have written about many times, we do have QA/QC requirements for newly installed (and repaired) piping. So here is what API 570 (the code referenced by the GC) says about piping inspections during installation and service changes…
(emphasis by me)
6.2 Inspection During Installation and Service Changes
6.2.1 Piping Installation
Piping shall be inspected in accordance with code of construction requirements at the time of installation (SAFTENG note – this is ASME B31.3 QA/QC requirements). The purpose of installation inspection is to verify that the piping is clean and safe for operation and to initiate plant inspection records for the piping systems. The minimum installation inspection should include the following items:
a) verifying that piping is installed correctly, the correct metallurgy is installed, supports are adequate and secured, exterior attachments such as supports, shoes, hangers are secured, insulation is properly installed, flanged and other mechanical connections are properly assembled and the piping is clean and dry;
b) verifying the pressure-relieving devices satisfy design requirements (correct device and correct set pressure) and are properly installed.
This installation inspection should document base-line thickness measurements to be used as initial thickness readings for corrosion rate calculations in lieu of nominal and minimum design thickness data in specifications, and design data sheets/drawings.
This will also facilitate the creation of an accurate corrosion rate calculation after the first in-service thickness measurements are recorded.