Which material is prohibited in the construction of flexible fluid lines?

The use of pure rubber in the construction of flexible fluid lines is prohibited primarily due to its susceptibility to degradation when exposed to various fluids and environmental conditions. Pure rubber can swell, lose structural integrity, or even break down when it comes into contact with certain petroleum-based oils, chemicals, or extreme temperatures. This inherent weakness makes it less reliable for fluid transport applications where durability and resistance to chemical interaction are critical.

In contrast, other materials such as PVC, polyurethane, and silicone are often used in fluid line applications due to their superior resistance to chemicals, varying temperatures, and physical stresses, making them better suited for maintaining the integrity and safety of the fluid transport systems.