Metal Bellows

Sometimes, operating conditions are so harsh, ordinary secondary seals won’t do the job. That’s when it’s time to call in the big guns—Qualiseal’s metal bellows seals.

Qualiseal offers metal bellows as a secondary sealing option for mechanical face seals. Providing exceptional sealing performance in highly toxic, corrosive, high temperature and/or high pressure environments, a metal bellows design can be the optimal solution to solve the most difficult sealing challenges. 

The bellows function as the secondary seal, as the spring to hold the primary seal against the mating ring, and as the anti-rotational lock.

Only the most complex and demanding applications require the high performance and reliability of a bellows seal.

Click here to download a Qualiseal metal bellows success story.

Ideal For:

  • Extremely high temperature fuel, oils and gases
  • Extremely low temperatures such as liquid oxygen refrigeration systems
  • Examples include aircraft engines and rocket propulsion systems


  • Enables high chemical resistance
  • No dynamic O-ring required, eliminating the possibility of hang-ups or compatibility issues
  • Hydraulically balanced metal bellows allow the seal to handle more pressure without heat buildup
  • Can fit into same space as existing face seals
  • Moderate operating lengths with compact construction

Operating Conditions (custom design can permit higher limits):

  • Pressure from full vacuum to 100 PSID (689 kPa)
  • Temperatures: -65°F (-54°C) to over 1,000°F (537°C)
  • Rubbing speeds to 50,000 FPM (254 m/s)

Design Configurations:

  • Can utilize either an O-ring on the outer diameter in a slip fit application, or can be designed to press fit into the seal bore of your unit
  • Unbalanced or balanced designs
  • Seal designs incorporate seal face material grades to encompass a wide range of applications, including high-pressure velocity (PV) or extreme vibration applications

Primary Face Materials:

  • Carbon
  • Bronze
  • Silicon Carbide
  • Tungsten Carbide
  • Others


  • Fuel Pumps
  • Starters
  • APU’s
  • Engine Main Shafts
  • Pumps (Various Fluids)
  • Industrial Applications

Industries Served:

  • Aerospace
  • Industrial
  • Food
  • Military

Contact us to learn more about our Metal Bellows.