Jointing copper pipework with a fitting that contains an integral solder ring is classified as what type of joint?

Jointing copper pipework using a fitting that contains an integral solder ring is classified as a capillary joint. This type of joint utilizes the principle of capillary action, whereby the molten solder is drawn into the space between the pipe and the fitting as it cools down.

In capillary joints, the design of the fitting ensures that when heat is applied, the solder melts and fills the small gap between the copper pipe and the fitted edge. Once the heat is removed, the solder solidifies and forms a strong bond that is watertight. This method is common in plumbing for its reliability and the ability to create seamless connections that can withstand high pressures.

Capillary joints differentiate from other types such as compression joints, which rely on a mechanical fitting to create a seal by compressing a rubber washer against the pipe; mechanical joints, which often use fasteners or clamps instead of solder; and flared joints, which involve a specific flaring of the pipe end to facilitate a connection. Understanding the characteristics and applications of these joint types is crucial for effective plumbing practices and ensures the integrity of the plumbing system.