Watertapping

Watertapping is the process of creating a branch from a pressurized water main or service line to supply water to a building or facility. It is typically performed by municipal utilities or licensed plumbers and is regulated to maintain water quality and system pressure. The term can also refer to tapping into an existing distribution line in industrial contexts.

Tapping can be performed while the main is in service (hot tapping) or after temporarily isolating the line (cold tapping). In hot tapping, a tapping machine makes a hole in a live line while a valve and branch connection are installed; in cold tapping, the main valve is closed, the line is drained or de-pressurized, and the connection is made. Common methods include using a tapping sleeve and valve, or a tapping tee and service saddle. After installation, the service line is connected and the new branch is tested for leaks and backflow risk. When the main must remain in service, the hot-tap method minimizes interruption but requires specialized equipment and skilled personnel.

Design and materials vary with local codes and service requirements. The curb-to-building service line often uses copper, PEX, CPVC, or ductile iron, with protective coating and insulation as needed. The connection to the main uses a properly sized valve, often a curb stop or corporation stop, and may include a backflow preventer or air chamber. Disinfection and flushing are performed to ensure water quality before the system is placed into service.

Regulation and safety considerations are central to watertapping. Permitting, coordination with the water utility, and adherence to cross-connection control and pressure-testing standards help prevent contamination and service disruption. Improper tapping can lead to leaks, contamination, or legal penalties.