Rectangular U-Ring Packings are made in a wide range of cross-sections and diameters from less than 1 inch ID to over 24 inches OD. Although there are few industry standards on U-Ring configurations, Zatkoff has established two standard cross-sections to provide a uniform series of seals for the most popular cylinder bore sizes. The two cross-sections, 1/4” W x 3/8” Ht. and 3/8” W x 1/2” Ht. are well accepted by cylinder manufacturers and equipment builders.
As ram packing in hydraulic cylinders, it is common to use a much larger U-Ring design to accommodate the wide clearances and bore excentricities that may exist.
U-Rings of this type are normally supplied in NEO-FAB material to resist extrusion and high shock loads. For special applications, the standard Fabric reinforced packing may be provided with a hard extrusion resistant heel material added to enhance its load carrying capacity. For pneumatic applications, this same configuration U-Ring is available in a resiliant 80 Shore A durometer nitrile compound.