Surface Deviations - Pitted FlangeOver time, and for any number of reasons, flanges are prone to surface deviations.  Damaged areas will tend to create a leak path that the gasket must try to seal.

Flange damage most commonly occurs when removing previously used gasket material from the sealing surface - tools such as chisels, or screw drivers, should be avoided. A brass wire brush is suggested.

The video below proves how well GORE® Gasket Tape Series 500 works on flanges with surface deviations versus a standard filled PTFE gasket.

[embed]https://www.youtube.com/watch?v=nwuxtiFbxH0[/embed]

Common types of flange surface damage (according to Pumps & Systems article Manage & Understand Flange Face Damage, by Randy Wacker):

  • Scratches—This type damage is narrow and elongated with sharp, shallow bottoms. However, depending on the force that created them, they can be deep. Frequently, this type damage is created by a sharp object dragging across the flange face. These objects may include the bristles of a wire brush or a tool, such as a chisel.
  • Gouges—These are wide and elongated with blunt, rounded bottoms and are created by a dull object dragging across the flange face. Gouges can be caused by objects—such as a screwdriver, flange jack or chisel.
  • Pits—This damage is usually small, somewhat rounded areas of concentrated material loss created by corrosion. Often, pits occur in clusters or groups.
  • Dents—This type damage can be sharp or blunt non-elongated areas caused by some form of impact. Dents sometimes result from equipment collisions caused by positioning the mating flanges using cables and rigging.

GORE® Gasket Tape Series 500 is made of 100% expanded polytetrafluoroethylene (ePTFE), using a proprietary Gore manufacturing technology that delivers exceptional sealing reliability, especially on large, damaged, or irregularly shaped steel flanges.

Because of its internal structure, GORE® Gasket Tape Series 500 excels at resisting cold flow and creep. Tests prove GORE® Gasket Tape Series 500 is nearly twice as effective at resisting creep than other brands of ePTFE tapes.

Gallagher Fluid Seals is a longtime distributor of GORE® Sealant Products.  If you want to learn more about GORE® Gasket Tape Series 500 or have any questions, please feel free to contact us for more information.