Mechanical Seal FC Seal

Dry-Running Secondary Containment Seal

Mechanical Seal Style FC

In certain processes, dangerous and volatile fluids require additional precautions to protect personnel, ensure safe operation, and prevent downtime. The Flex-A-Seal Fluid Containment (FC) Seal has been specifically designed as an economical option for applications where the highest level of safety and environmental control is necessary. The FC Seal allows monitoring of any any primary seal leakage and functions as a secondary containment seal in the event of any primary failure.

The FC Seal is a contacting, dry-running seal which can be added to most of Flex-A-Seal’s single cartridge options, including:

  • Style 63 or 66 high temperature cartridge seal
  • Style 58 heavy duty API stationary multi-spring cartridge seal
  • Style 53A API rotating welded metal bellows cartridge seal
  • Style SMS stationary multi-spring cartridge seal
  • Style RB rotating welded metal bellows cartridge seal


  • Welded metal bellows technology maintains a uniform light load on dry running seal faces for long seal life
  • Stationary design enables optimum face tracking
  • Static O-ring position eliminates friction during operation and potential failures caused by O-ring hang up
  • Seal faces are heat shrunk retained for higher strength and torque transfer – no pin drive
  • Most commonly used with API 682 Plans 72 and 76



Faces:Special Dry-Running Carbon, Silicon Carbide
Elastomers:Viton®, Ethylene Propylene, Aflas®, Buna, Neoprene, Perfluorelastomers
Metallurgy:316 stainless steel, 17-4 stainless steel; Additional options include Hastelloy® C-276, Super Duplex stainless steel, Titanium
Bellows:Hastelloy® C-276, Heat-treated Inconel 718, Heat-treated AM350; Double-ply bellows designs are also available.

Operating Conditions

Speed:10000 FPM (50 m/sec)
Temperature: Low Temp Design:up to 400°F (204°C)
High Temp Design:up to 800°F (425°C)
Pressure: Primary Seal (product):as specified by selected single seal design
Secondary Seal (dry-running):up to 10 PSI (7 Bar)

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 Flex-A-Seal if in doubt.



Quote Request

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

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