DEPAC seal type 322 is a tandem – active, stationary design cartridge mounted double mechanical seal with an integrated barrier fluid pumping device. This seal type is double pressure balanced which guarantees lower face pressure, lower face friction and therefore less wear on the face pair. Additionally full pressure rating is possible on pump and barrier fluid side and the seal faces are self-closing in case of pressure reversal. Available product variants type 321 and type 323 for smaller and bigger sealing chamber cross sections round out this seal’s universal application opportunities.


  • Integrated barrier fluid pumping device
  • Tandem-active arrangement
  • Cartridge mounted
  • Double pressure balanced - full pressure rating possible on pump side AND barrier side
  • Self-closing in case of pressure reversal
  • Venting option
  • Direction of rotation independent
  • Multiple spring design and springs made of Hastelloy C
  • No clogging of springs
  • Shock and vibration dampened secondary seal faces

Technical specifications

Operating range*

  • Pressure: 700 mm Hg up to 28 bar
  • Temperature: depending on Elastomer
  • Sliding velocity: up to 35 m/s

Maximum temperature / pressure / speed indicates operating extremes independently and does not imply the seal will function at these extremes at the same time. Contact Pactor if in doubt.


  • Shaft diameter: 24mm – 160 mm
  • Inch Sizes also available
  • Special sizes available on request


  • Metal parts: 1.4571
  • Springs: Hastelloy C
  • Seal faces:
    • Silicione carbide (Q1, Q2)
    • Tungsten carbide (U2)
    • Carbon graphite (A, B)
  • O-Rings:
    • FKM
    • EPDM
    • PTFE
    • FEP wrapped
    • Silicone
    • AlfasR
    • KalrezR
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