How can injectable sealants solve my sealing problems?
by This month’s “Sealing Sense” was prepared by FSA members Alfred Cooper and Michael Drotos, Sr.
April 1, 2013
  • High-temperature service—Injectable sealant made from graphite fibers and high-temperature lubricant and fillers is formulated to perform in high-temperature applications. Due to the excellent heat dissipation property of graphite, friction heat and process heat will easily dissipate through the sealant to the surface of the pump box. This action allows the packing to continue to run at an acceptable temperature without burning the lubricant in the sealant.
  • Food and beverage or pharmaceutical applications—Specially processed U.S. Food and Drug Administration (FDA) compliant PTFE fibers with approved food-grade lubricant is used to seal the pump stuffing box with two end rings of FDA-compliant packing material. The PTFE low friction capability allows the pump to operate without high frictional heat, which can damage the packing and shorten seal life.
  • Abrasive service—A compound made from meta-aramid fibers or high-strength, spun aramid fibers blended with high-grade lubricant is used to seal mine slurries, paper stocks and most media with suspended abrasive particles. The end rings used with the sealant are also made from high-strength packing yarns. Because of the high tensile strength of the aramid, the suspended solids are prevented from destroying the packing.

Injectable sealants have been around for years. These products are versatile sealing solutions. Typical equipment that can use injectable sealants is centrifugal pumps; reciprocating pumps; and rotary mixers that handle cooling water, aqueous solutions, oils or solvents, particularly in processing sectors such as pulp and paper, metallurgical, and mineral and power. Injectable sealants are often used because they readily conform to worn shafts or irregular housings.

The combination of high-performing fibers and specially treated fillers and lubricants also make these sealants a viable alternative to conventional packing and has help improved meantime between maintenance for many types of equipment. Process plant operators have reported annual savings of up to 30 percent in maintenance costs and a significant reduction in plant water usage when they converted problem pumps and valves to injectable sealants.

Next Month:
How can packing solve my difficult sealing problem?