GYLON®, a product of Garlock Sealing Technologies, is a reinforced PTFE gasketing material that offers significantly reduced creep relaxation, cold flow, and excellent chemical resistance, along with easy identification due to branding and color coding.

GYLON® 3565 ENVELON® Benefits

  • Tighter seal – on wavy or glass-lined flanges because of low bolt load requirements
  • Ability to conform to surface irregularities – its soft, deformable exterior is perfect for pitted, warped, or worn flanges
  • Elimination of leak-path and adhesive contamination  – GYLON® layers are directly sintered, which makes this possible
  • Easy installation – its rigid core assists in the instillation of large gaskets, and its unitized construction bypasses jacket foldover
  • Inventory reduction – due to the availability of large sheets for convenient custom-cut gaskets; ideal replacement for milled, slit, formed shield, and double jacketed envelope gaskets


GYLON® 3565 ENVELON® Material Properties

Color: White exterior and blue interior
Composition: PTFE with aluminosilicate microspheres
Fluid Services: Moderate concentrations of acids, some caustics, hydrocarbons, solvents, hydrogen peroxide, refrigerants, and cryogenics
Min. Temperature: -450 (°F)
Continuous Max: 500 (°F)
Max. Pressure: 1200 (PSI)
Maximum PxT 1/16: 350,000 (°F x PSIG)
Maximum PxT 1/8: 250,000 (°F x PSIG)
Flammability: Will Not Burn
Bacterial Growth: Will Not Support
Meets Specification: FDA (Food and Drug Administration)