Medium-density bare spheres are constructed of 5 pound per cubic foot density foam. They are used for drying and sweeping of loose debris. However, other functions include using as a gauging pig for determining internal pipe conditions prior to extensive pigging, using as a sealing pig behind a stuck pig, using for batching and product removal, and for pigging where low volumes and pressures are present. Options and other configurations include customized diameters for special pigging applications.