nonvelope gasket hero

A superior envelope gasket

The Nonvelope was developed by VSP Technologies out of a need to fix a problem with traditional envelope gaskets. Traditional envelope gaskets suffer from fold back when applied in tight flanges, which exposes the metallic layer leading to a shorter lifetime of the gasket. The nonvelope solves this problem by encapsulating the metallic layer in either PTFE or ePTFE. This method also allows the nonvelope gasket to conform to damaged flanges through the corrugated metal insert. This leads to a tighter seal and a longer life time for the gasket overall.

encapsulated envelope gasket


  • No foldback
  • One-piece envelope gasket
  • Easy installation even between tight flanges
  • Longer gasket life due to the metal insert not being exposed to the process
  • Easily conforms to damaged flanges
leak rate of envelope gaskets over gasket stress graph

Target Applications / Industries

  • Corrosive process piping
  • Vessel flanged systems
  • FRP flanges
  • Teflon lined flanges
  • Plastic flanges