Which of the following are types of thermal expansion joints?

Thermal expansion joints are crucial in piping systems as they help accommodate changes in pipe length due to temperature variations. Among the options provided, bellows type represents a common mechanism designed specifically to handle the thermal expansions and contractions of pipelines. Bellows are flexible, accordion-like structures that can absorb movement while maintaining the integrity of the piping. Therefore, the inclusion of bellows type in the answer highlights a method that effectively compensates for thermal expansion.

The slip type, on the other hand, refers to a joint that allows for longitudinal movement by permitting one pipe section to slide over another. This is often employed in systems where there are significant changes in temperature and thus length, making slip type a fitting complement to bellows type when discussing thermal expansion joints.

The combination of slip type and bellows type illustrates both sliding and flexible mechanisms, providing a comprehensive approach to managing thermal expansion in plumbing systems. Understanding these types is essential for effective plumbing design and ensuring system longevity and reliability.