Plumbing is any system that conveys fluids for a wide range of applications. Heating and cooling, waste removal, and potable water delivery are among the most common uses for plumbing; however, plumbing is not limited to these applications. Plumbing utilizes pipes, valves, plumbing fixtures, tanks, and other apparatuses to convey fluids. Trades that work with plumbing such as boilermakers, plumbers, and pipefitters are referred to the plumbing trade. In the developed world plumbing infrastructure is critical for public health and sanitation.