K-MOS Mechanical Oil Seal

Kaydon Ring & Seal has supplied the industry with reliable, hard-working oil-buffered mechanical seals since the 1930’s. Mechanical seals are ideal for services that require tight shutoff during standby periods, such as refrigeration applications. The Kaydon mechanical oil seal (K-MOS) is the culmination of design and material advancements to provide the highest level of quality and performance available.

The K-MOS operates by using oil at 30-45psi above process gas pressure to contain process gas inside the equipment body. The mechanical seal faces work to minimize the amount of oil flowing to the sour drain pots. Leakage is collected in drain pots where it is either treated and re-used or discarded. Sour oil leakage is normally less than five gallons per day and less than one gallon per day during standby. If you are experiencing higher levels of oil consumption with your current mechanical seals, contact us to discuss solutions.

Features and Benefits

  • Low sour oil leakage during operation
  • Near zero standby leakage
  • Pressure balanced face seal design minimizes friction wear
  • Steel retainers for carbon sealing rings provide durability and stability to critical components
  • Solid PTFE dynamic secondary seals reduce the possibility of seal “hang up”
  • Integral process side windbacks direct leakage to drainers, and out of the process stream
  • Rotating seal faces are hard-coated for longevity
  • Generous axial float allowance
  • Cartridge design for easy installation
  • Typical seal run times of 5-8 years between overhaul


  • Natural gas transmission
    • Pipeline booster compressor shaft seals
  • Natural gas and CO2 re-injection compressor shaft seals
  • Natural gas processing plants
    • Propane refrigeration, sales gas, raw gas, residue gas compressor shaft seals
  • LNG refrigeration and boil-off compressor shaft seals
  • Refinery
    • Hydrogen recycle, platformer, reformer, wet gas, coker, alkylation, isomerization, flare gas recovery, crude unit
  • Petrochemical
    • Ethylene, propylene, polypropylene, charge gas, propane refrigeration, iso-butane, ethylene oxide, styrene off-gas, low density polyethylene (LDPE), linear low density polyethylene (LLDPE), polyethylene, carbon monoxide, methanol, synthesis gas, ammonia refrigeration, acetylene, feed gas

Why Kaydon Ring & Seal?

Customers choose Kaydon seals for their reliability and time-proven performance.  Each Kaydon seal is pre-tested at full pressure and speed to verify performance. Shop tests are available for customer witness. Your pre-tested seal cartridge arrives ready to be installed in minutes versus days for component seal designs.

Kaydon has the broadest range of compressor seal types available in the industry.  Our goal is to supply you with the best solution for your circumstances, whether it is repair, upgrade or replacement of your existing seal.