DuraClear Synthetic Fluid
Product Brand
Barrier Fluid
About this product

DuraClear Crystal 7 combines exceptional lubricating properties with comprehensive chemical compatibility for optimum performance as a mechanical seal barrier fluid.

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Strong chemistry enables strong performance. DuraClear Crystal 7 is a perfluoropolyether (PFPE) based fully synthetic oil. Comprised of fully bonded oxygen, fluorine and carbon atoms, this extremely stable molecule is equally extremely inert.

  • Nontoxic
  • Nonreactive
  • Nonoxidizing
  • Colorless
  • Odorless
  • Nonflammable
  • Does not degrade with use or temperature
  • Does not coke or crystallize
  • Environmentally friendly
  • Food grade

Compatible with all seal face materials

  • Carbons
  • Silicon Carbides
  • Tungsten Carbides

DuraClear Crystal 7 is a Perfluoropolyether (PFPE) based oil which offers several benefits over ISO 7 grade CTFE fluids:

  • Better compatibility with Lewis acids
  • Better lubrication capability (lower seal face wear)
  • More thermally stable
  • No corrosive Chlorine in molecular chain
  • Flatter viscosity curve vs temperature


ISO grade of oil: 7

Viscosity ASTM D445

  • 16 cSt at 20°C (68°F)
  • 8 cSt at 40°C (104°F)
  • 2 cSt at 100°C (212°F)

Pour Point: <-70°C (<-94°F)

Density g/ml

  • 1.89 at 0°C (32°F)
  • 1.70 at 100°C (212°F)

Recommended process fluid temperature range: -60 to 204C / -76 to 400F

Barrier fluid operating range: -40 to 130C / -40 to 266F

Optimal barrier fluid operating range: 20 to 100C / 68 to 212F

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