Chesterton 3000 Soot Blower Sets are molded from an exclusive mixture containing graphite and PTFE along with other materials.  3000 sets are designed with a thicker than usual top ring to act as a bearing for the set and to resist extrusion. All rings are split to go over the rod without being deformed. Exclusive Chesterton formulation and processing allows rings to slip over rod and return to their molded contour without cracking. Sealing rings are designed so the top of each ring protects the ring above it.  This eliminates the majority of lip damage normally associated with early set failure. Sealing ring lips expand inward and outward as increased gland pressure is applied.  The tapered lip design allows the rings to respond readily to steam pressure, assuring increased sealing efficiency and longer life during operation.