On exceptionally large pumps, agitators, mixers, autoclaves, filters, calenders, fermenters and similar units with large shafts there is often a tendency for the shafts to wander well off center.

This is evident not only in axial and radial movements but also in pendulating movements.

Conventional mechanical seals cannot cope with these extreme conditions. For these applications DEPAC can offer seal type 365 with “floating” seal faces which absorb these extreme movements in the seal itself and still hold the faces together with the same pressure conditions.

These mechanical seals work reliably and completely independently of any shaft movements.


  • Motion tolerances +/- 3,0 mm* axial, radial und pendulating
  • Cartridge mounted
  • Double pressure balanced - full pressure rating possible on pump side AND barrier side
  • Self-closing in case of pressure reversal and Tandem-active arrangement
  • 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 25 m/s
  • Shaft movements:
    • axial +/- 3,0 mm
    • radial +/- 3,0 mm

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: 25 – 200 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
    • Alfas
    • Kalrez
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