Abstract: The invention relates to a safety packer assembly for use in a cement-lined pipe. The assembly provides for the use of a packer body which carries one or more resilient collars that expand in response to a compression force created by rotation of an upper part of the packer body. A safety valve is provided in the upper part of the packer body to prevent escape of the downhole pressure. A safety centralizer is detachably secured to a lower part of the packer body, the centralizer being provided with a plurality of arcuate resilient members which extend along the length of the centralizer body and frictionally contact the wall of the cement-lined pipe to maintain the packer body in its predetermined position within the pipe and resist rotation of a lower part of the packer body when the upper part is rotated.

Abstract: The invention relates to drum containers provided with one or more rolling hoops. The drum has a continuous vertical side wall provided with one or more reinforced portions. Each of the reinforced portions is provided with an outwardly convex rolling hoop located between a pair of inwardly concave annular grooves formed in the side wall of the drum. The vertical dimensions of the grooves are at least twice the size of the grooves' depth, while the vertical dimension of the rolling hoop is at least twice the horizontal projection by which the rolling hoop extends outwardly from the side wall.