These solid-cast urethane pigs are used primarily in the food and beverage industry and in processing facilities that handle multiple products in the same lines, such as train-loading stations. They remove residual product and clean the line sufficiently for the next product to pass through with minimal cross-contamination. They are designed for lower-pressure food-processing systems and are not typically used in oil and gas pipelines because their sizing differs to accommodate lower operating pressures, although exceptions exist. These pigs often contain magnets that activate sensors in automated systems.