A pipefitter helper works as an apprentice to become a plumber. You assist the plumber in fitting pipes onto pressurized systems. You may also work on installation projects for piping systems. These piping systems can be used for a number of substances like water, oil, and chemicals. You train to learn one of five separate plumbing disciplines. Your job duties include fitting, cutting, assembling, and repairing these systems. You must be knowledgeable about how the complete system works since they are highly pressurized and can reach very high temperatures.