What are two reasons for using cast iron piston rings?

Using cast iron piston rings is primarily advantageous due to their ability to withstand higher temperatures and higher pressures. Cast iron possesses excellent thermal stability, which allows it to perform effectively in high-temperature environments without compromising its structural integrity. This characteristic is essential in applications where heat is generated due to friction or external conditions, ensuring longevity and reliability in operation.

Additionally, cast iron's strength and durability contribute to its proficiency in high-pressure applications. The material’s resistance to deformation under stress makes it suitable for maintaining a good seal within hydraulic cylinders, which is critical for the efficient functioning of hydraulic systems. This sealing ability prevents fluid leaks and ensures that systems can operate effectively under demanding conditions.

While lower costs and compatibility with hydraulic fluids are relevant considerations when selecting materials, they do not capture the primary attributes of cast iron piston rings. Reduced friction and wear are certainly important factors in the context of piston rings, but the standout features of cast iron relate to its performance at elevated temperatures and pressures. Therefore, emphasizing the material's strength and thermal stability under these conditions provides a clearer understanding of its role in hydraulic systems.