Introduction to Plumbing: Plumbing encompasses the systems and practices for supplying water, removing waste, and, in many cases, conveying fuel gases in buildings. In general, plumbing is defined as the installation, maintenance and alteration of pipes, fixtures and appliances used in potable water delivery, sanitation (wastewater and storm drainage), and venting . A typical plumbing system has three main parts: (1) a water-supply system of pipes, fittings and valves that brings fresh water into the building; (2) a drainage/waste system that carries sewage and greywater safely out to sewers or septic tanks (including vents to prevent sewer gas buildup); and (3) fixtures and appliances (toilets, sinks, water heaters, etc.) where water is used. Many plumbing systems also include fuel-gas piping to supply natural gas or propane to stoves, furnaces and water heaters . (For example, one source notes “Gas plumbing systems are used for supplying gas to stoves, furnaces, ovens, and water heaters” .) Together these components ensure a clean potable water supply, effective removal of waste and protection of public health. - Water Supply: A network of pipes and valves delivers clean water (from municipal or well sources) to all faucets, showers, toilets and appliances. Plumbers install and maintain this pressurized distribution system using materials like copper, PEX or PVC pipe . - Drainage & Waste: A separate piping system carries used “grey” and sewage water away. Gravity-driven drains (PVC, cast-iron, etc.) and vents channel wastewater to sewer or septic systems . - Gas Piping: Where applicable, a plumbing contractor also installs fuel-gas lines. Rigid iron or CSST tubing conveys natural gas/propane safely to appliances (stoves, water heaters) under plumbing codes . - Venting: Plumbing vent stacks are an integral part of the drainage system, preventing traps from siphoning by letting air into the pipes. Together, these sub-systems (water supply, drainage/waste, fuel gas, venting) form the full plumbing network of a home or building . Plumbers must understand all parts of this system to keep water flowing safely and waste moving efficiently.