Mechanical Seal Style 85M

Heavy Duty Split Cartridge Mechanical Seal

Designed Specifically for Mixers and Agitators

The Flexaseal Style 85M Heavy Duty Split Cartridge Mechanical Mixer Seal applies the same innovative technology we use in our Style 85 Split Cartridge Mechanical Seal but designed specifically to meet the challenges of sealing mixers and agitators, centrifuges and other special rotating equipment. Mixers are known for having a much larger radial shaft run-out than typical pumps, and using a conventional split seal design for a standard pump would significantly reduce the performance and life of the seal.

The Flexaseal Style 85M is specifically designed to handle this additional shaft movement, increasing long-term seal reliability while giving you the best performance you need for your equipment. Plus, the Style 85M features the same ease of installation as our standard Style 85.

Style 85M


  • Flexaseal two-piece split cartridge mechanical seal
    • Fastest Split Cartridge Mechanical Seal Installation in the world.
    • Only two cartridge halves are handled – no loose or delicate components can be dislodged, lost, or damaged
  • True Cartridge Seal Style Setting Clips
    • Provides for correct setting and alignment of the seal assembly, which helps to eliminate the number one cause of split seal failure.
    • No measurements, shims, or special tools required.
  • Precision Lapped Split Faces protected together inside metal sleeve and gland
    • Dirt and grease cannot get between the precision lapped faces.
    • Metal components protect faces from mishandling damage such as being cocked or chipped.
  • Hydraulically Balanced Seal Faces
    • Lowers seal face heat generation.
    • Provides a wider range of operating pressure for more reliable sealing.
  • Large Radial Clearances allows for more shaft movement without damaging any of the seal’s components.
    • Equipment like mixers and agitators are known for having much larger radial shaft run out than a typical pump. Installing a seal specifically engineered to handle this additional shaft movement is extremely important for long term, reliable seal life.
  • Stationary Seal Design
    • Insures optimum seal face tracking and alignment.
    • Springs do not have to flex with every revolution.
  • Large Diameter Cross Section Dynamic O-Ring slides on smooth clean stationary seal ring surface
    • Eliminates all shaft or sleeve damage due to fretting.
  • Multi Springs located and protected inside the cartridge seal gland
    • Not in contact with sealed fluid.
    • Non-clogging and corrosion resistant.
    • Self-contained spring eliminates the possibility of losing one or more during installation.
  • Heavy Duty rotating seal drive components
    • Sleeve drive pins ensure positive direct drive to the rotating face.
    • Set screws securely lock the seal firmly in place and allows for higher pressure capability that clamped arrangements cannot provide.
  • Standard NPT Flush Connection in Gland
    • Helps to improve the seal environment with a means for venting or flushing providing for a more reliable seal.
  • Cartridge Sleeve O-Ring located outside the stuffing box
    • Especially important when converting from packing: the cartridge O-ring seals on the undamaged surface of the equipment’s shaft or sleeve.
  • Larger, Thicker Gland Gasket
    • A beefier gasket ensures a better seal against any slight surface imperfections of the chamber’s face.


Materials of Construction

Rotating Face: Silicon Carbide
Stationary Face: Carbon or Silicon Carbide
Elastomers: Viton® Standard
Aflas® or Fluoraz® Option
Metal Parts: 316 S.S.
Springs: Hastelloy® C-276

Operating Parameters

Size: 1 ½” – 9″ (38mm – 228 mm)
Temperature: 350°F (175°C)
Speed: 1 ½” – 3” – 3600 RPM
3 1/8” – 4 ¾” – 1800 RPM
4 7/8” – 9” – 875 RPM
Pressure: Up to 450 Psig (30 Bar)
Runout: Up to .060 (1.5 mm) TIR
Radial movement

Note: Max Temperature / pressure / speed indicate operating extremes independently and do not imply the seal will function at these extremes at the same time. Contact Flexaseal Engineered Seals and Systems, LLC if in doubt.

Contact Flexaseal Sales at (802)878-8307


Quote Request

Depending on your specific needs and application, Flexaseal can help you identify the ideal products. Contact us to tell us about your needs and request a quote.