F04000-180 Stack Packing is to be used as a split ring seal or as a direct replacement for V-type packing. It is designed for use in rough plungers, in oversized packing boxes, in undersized pistons, and in “barber pole” or in “hour glass” pistons. In sizes smaller than 6-1/2”, a maximum of 3 rings should be used with the remaining space taken up by spacers to compress the sealing rings. All sealing rings and spacers are split for easier installation.