What material is commonly used to make shaft sleeves in a centrifugal pump?

The correct answer is steel or copper, which are commonly used materials for making shaft sleeves in centrifugal pumps due to their desirable mechanical properties.

Shaft sleeves are critical components that protect the pump shaft from wear and corrosion caused by the fluid being pumped and the mechanical action of the pump. Steel is particularly preferred because of its strength and durability, ensuring that it can withstand the stresses and strains of pump operation. Additionally, steel can handle high levels of pressure and is resilient in various operating conditions.

Copper, on the other hand, is often utilized because its antimicrobial characteristics can help reduce the buildup of biofilm in water systems. It's also resistant to corrosion to some extent, although it is usually used in less demanding applications compared to steel.

Both materials provide a combination of wear resistance and structural integrity, making them suitable for the applications in centrifugal pumps. Other materials, like aluminum or plastic, might not offer the same level of hardness or resistance to wear and damage under the conditions that centrifugal pumps typically operate in. Brass can be suitable in certain applications, but it generally does not offer the same strength or thermal resistance as steel for this particular use.