Before you get involved with most plumbing projects, you'll need to shut off the water flowing to whatever you're working on. Most of the time, there are easy-to-access gate valves or compression valves that you can turn with your hand. Turn them clockwise all the way to turn off the water and counter-clockwise to turn it back on when you're done. For sinks, look under the sink and you'll usually see two valves—one for hot water and one for cold. On kitchen sinks, you might also see valves for the ice maker on your fridge or your dishwasher. Just turn them all off. For toilets, the valves are on the wall or right on the pipe behind the toilet.
Most plumbers, pipefitters, and steamfitters learn their trade through a 4- or 5-year apprenticeship. Apprentices typically receive 2,000 hours of paid on-the-job training, as well as some classroom instruction, each year. In the classroom, apprentices learn safety, local plumbing codes and regulations, and blueprint reading. They also study mathematics, applied physics, and chemistry. Apprenticeship programs are offered by unions and businesses. Although most workers enter apprenticeships directly, some start out as helpers. The Home Builders Institute offers a pre-apprenticeship training program in plumbing and other trades.
Plumbers in Australia have licensing requirements that differ from state to state but it is generally accepted a 4-year apprenticeship with a further minimum experience of 2 years (6 years total) and a further curricular requirement as a benchmark for licensing. Licensed plumbers are also expected to maintain minimum relevant training requirements to maintain their plumbing license