What is a common method used to connect pipes in plumbing?

Soldering is a common method used to connect pipes in plumbing, particularly for copper pipes. This process involves melting a filler metal (solder) to join the pipes together. The heat from a soldering torch allows the solder to flow into the joint, creating a strong, watertight seal once it cools and solidifies. Soldering is widely used because it is effective for joining pipes that will carry water and other liquids, ensuring durability and leakage prevention.

In addition to soldering, the other methods listed have different applications and are not typically suited for standard plumbing connections. Welding, for instance, is generally reserved for thicker metals used in structural applications rather than for conventional plumbing tasks. Cold fusing is a process associated with certain types of plastics and is not applicable to traditional metal plumbing systems. Drilling does not serve the purpose of connecting pipes but rather involves creating holes or access points in materials. Thus, soldering stands out as the standard technique for joining pipes in plumbing systems.