What is a disadvantage of a welded joint in piping systems?

A welded joint is known for its strength and durability; however, one notable disadvantage is that it may form slag inside the pipe. This is due to the welding process, where impurities can become trapped as the metal solidifies. This slag can disrupt flow and create blockages, which can compromise the efficiency of the piping system.

While other options also present potential drawbacks of welded joints, they are not particularly inherent disadvantages. For instance, difficulty in repair can be a concern for any type of joint, not exclusively welded joints, as both welding and other methods require specific skills and resources for repair. Similarly, while welded joints can potentially impact flow, the increase in friction is more dependent on factors like the pipe diameter, fluid velocity, and surface roughness rather than solely on the welding itself. Lastly, the claim that welded joints become weaker at high temperatures is misleading; in many cases, welds are designed to maintain their strength under heat, especially if proper materials and techniques are used. Thus, forming slag is a unique disadvantage associated with the welding process itself.