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Fishbone with AIGI
Round Edged Beveled Ribs

Fishbone with AIGI
Round Edged Beveled Ribs

• Specially configured graphite coated ( or PTFE coated) round edged beveled metal ribs when compressed create separate sealing chambers that breakdown system pressure across the gasket face. The sealing element covering the rib tip also becomes more densified creating an alternating sequence of sealing chambers with “safety or back up” seals of densified sealing material at the point of contact between the rib and flange face.

• The thickness and angle of the round edged beveled ribs- theoretically designed but validated and improved through an iterative trial and error process- create a “bending moment” under bolt load that compresses and stresses the graphite. The “bending moment” also provides a self-energizing effect which effectively creates an internal “Live loading” system.

• Unlike SWGs and Kamprofile gaskets which have sharp metal surfaces, all surfaces on the Fishbone gasket are rounded to avoid the possibility of flange damage.

Patented Stop-step Design 

• An internal rounded stop-step, which is integral to the design, provides a positive stop thus preventing over stressing of the ribs and the graphite sealing element. The stop-step insures that the ribs remain elastic and functioning in their self-energizing capacity because it prevents them from being stressed beyond their elastic limit. The same is true for the graphite sealing element. The ribs, stop-step and graphite sealing element perform as an integrated system to insure maximum sealing performance under bolt load.

• The terminal ID beveled ribs also provide an elastic element that can be energized by the system pressure helping to create a tighter seal.

• Being a fully CNC machined solid piece of metal the gasket does not have the typical issue of unwinding like SWGs.

• Because of the design, one gasket type can be used to replace both CG and CGI type SWGs ( now the API standard for refineries) and all Kamprofile gaskets.

Benefits & Advantages

  • Internally self-energized and by fluid pressure for better sealing performance

  • Interchangeable with all spiral wound gaskets and Camprofile gaskets

  • Will not damage flange like Camprofile gaskets and spiral wound gaskets

  • Prevents over-compression of sealing element

Standard Materials

  • Metal Materials

  • 304, 304L, 316, 316L, 321

  • Non-metallic Sealing Materials

  • Flexible Graphite, PTFE

  • *Nuclear Graphite, Mica, Monel, Inconel and other materials are available on request.


  • Basic Construction - Type I

Fishbone with AIGI-4.jpg
  • Centering Ring Construction - Type II

Fishbone with AIGI-3.jpg

Replaces Spiral Wound Style CG, CGI & Camprofile Reinforced Type​

Temperature Range

Fishbone with AIGI-2.jpg

Standard Sizes


NPS (in): 1/2”, 3/4”, 1”, 1 1/4”, 1 1/2”, 2”, 2 1/2”, 3”, 4”, 5”, 6”, 8”, 10”, 12”, 14”, 16”, 18”, 20”, 24”

CLASS (lbs): 150, 300, 400, 600, 900, 1500, 2500


DN (mm): 10, 15, 20, 25, 32, 40, 50, 65, 80, 100, 125, 150, 175, 200, 250, 300, 350, 400, 450, 500, 600

PN (MPa): 1, 1.6, 2.5, 4, 6.3, 10, 16, 25, 32, 40

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