The interpreter looks for such things and porosity—or gas pockets which are small spherical or elongated holes and for slag inclusion, which is electrode coating material entrapped between individual weld passes; for cracks, which could result from for instance, handling of the pipe with only the root pass completed and for inadequate penetration, which is a condition where the root pass has not completely penetrated into the pipe., 1976-07, PCA0002-2b-43, Folder: PCA0002-2b. Alyeska Pipeline Service Company : Trans-Alaska Pipeline Construction Collection, 1976-1977, PCA 2. Alaska State Library - Historical Collections Finding Aids. https://alaska.libraryhost.com/repositories/2/archival_objects/17542 Accessed February 22, 2025.