Special heaters are used in cold weather to prevent hydrotest water from freezing. Pumps circulate warm water through the test section for a prescribed period prior to a test., 1977-04, PCA0002-4b-23, Folder: PCA0002-4b. 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/17815 Accessed February 22, 2025.