Which of the following materials should be removed from the surface of the pipe before installation?

The correct choice emphasizes the importance of ensuring that the surface of the pipe is free from any contaminants prior to installation. Grease and oil, in particular, can significantly impact the adhesion of materials and sealants used during installation. These substances can create a slippery surface that prevents proper bonding, leading to potential leaks and failures in the pipeline.

While removing loose rust, dirt, and water may also be necessary, the presence of grease and oil poses a more severe threat to the integrity of the installation. Therefore, focusing on removing all forms of contamination, especially grease and oil, is essential for achieving a secure and effective seal, promoting the longevity and reliability of the distribution pipe. This comprehensive cleaning approach helps ensure that the installation meets industry standards and performance expectations.