Robco Expert

As a rule of thumb,70% of shaft wear from braided packing is caused by the first and second rings adjacent to the gland follower. Why? Imagine you had 4 identical full cardboard boxes in a row and pushed on the first one, all 4 boxes would move as one. Packing does not react that way, as compressible braided packing needs to densify sufficiently to push on the next ring and so on. It is the bottom ring in the stuffing box that needs to be compressed in order to produce an efficient seal. But how can you get the load from the gland follower to this ring? The answer is to use die-formed, or pre-compressed packing rings, allowing the compressive load from the gland follower to move all of the rings equally. The obvious advantage is activating all the rings in the set, including the all important ring that sees the media to be sealed, while reducing overall friction on the shaft/sleeve. Good quality die-formed rings are usually provided as individual sets for each stuffing box, already ...

  5  important things to do  when replacing compression packing on a pump: By Jocelyn Vachon – Fluid Sealing Specialist and Packing Guru If you’re not doing these 5 things, you are increasing the chances of pump failure. Visual inspection of the packing rings:  As you remove the worn-out packing rings, inspect for unusual wear: this will reveal if a faulty element is causing damage and early failure (impregnated abrasive particles on the packing, torn areas, excessive wear on particular surfaces, over-compression, etc. Inspect equipment  for   excessive wear on the sleeve/shaft, excessive shaft eccentricity run-out, plugged water-line or limited pressure, bearings, etc. Install packing that meets the performance requirements : operating temperature, shaft speed, chemistry and potential abrasion. Install one packing ring at a time:  make sure packing is the right size (it should fit reasonably tight) and do not insert a spiral of packing into the stuffi...