Which of the following is a common type of joint used in copper pipe connections?

A solder joint is a common type of connection used in copper pipe systems. This method involves heating the copper pipe and the solder material until the solder melts and flows into the joint, creating a strong and durable bond once cooled. Solder joints are widely used in plumbing because they allow for a secure seal that can withstand high pressures and temperatures.

This technique is favored for its effectiveness in preventing leaks and its ability to create a smooth interior surface, which is essential for maintaining water flow within the pipes. Solder joints also do not require additional fittings, making them beneficial for certain installations where space is limited.

While compression joints, welded joints, and threaded joints are used in different contexts or with different types of materials, they are not as prevalent in copper plumbing as solder joints. Compression joints typically involve fittings that compress against the pipe, welded joints are more common in metalworking but not with copper plumbing, and threaded joints are used primarily with pipes that can accommodate threading, which does not apply to the majority of copper piping setups. Therefore, solder joints are the preferred choice for copper connections in plumbing.