To avoid replacement of the impeller or casing due to wear, what is commonly used inside the pump?

In a pump system, a mechanical shield is an effective technique used to prevent wear and tear on critical components such as the impeller and casing. This shield serves as a barrier between the fluids being pumped and the machinery, minimizing direct contact that could lead to abrasion or erosion over time. This design helps extend the lifespan of the pump by protecting it from the wear caused by the movement of solid particles or corrosive substances in the fluid.

While other options such as sealants, lubricants, and O-rings serve vital functions in mechanical systems—such as sealing leaks, reducing friction, and providing airtight seals—they do not specifically address wear protection for the impeller and casing in the same way that a mechanical shield does. Sealants are typically used for sealing gaps, lubricants are meant to reduce friction and heat, and O-rings work primarily for sealing, not for wear protection. Therefore, the use of a mechanical shield is the most relevant approach to prevent damage from wear within a pump.