Graco ProMix PD2K Repair Parts page 11

Moisture Sensitivity of Isocyanates
Exposure to moisture (such as humidity) will cause
ISO to partially cure; forming small, hard, abrasive
crystals, which become suspended in the fluid.
Eventually a film will form on the surface and the ISO
will begin to gel, increasing in viscosity.
NOTICE
Partially cured ISO will reduce performance and
the life of all wetted parts.
• Always use a sealed container with a desiccant
dryer in the vent, or a nitrogen atmosphere.
Never store ISO in an open container.
• Keep the ISO pump wet cup or reservoir (if
installed) filled with appropriate lubricant. The
lubricant creates a barrier between the ISO and
the atmosphere.
• Use only moisture-proof hoses compatible with
ISO.
• Never use reclaimed solvents, which may
contain moisture. Always keep solvent
containers closed when not in use.
• Always lubricate threaded parts with an
appropriate lubricant when reassembling.
332709D
Important Isocyanate (ISO) Information
NOTE: The amount of film formation and rate of
crystallization varies depending on the blend of ISO,
the humidity, and the temperature.
Changing Materials
NOTICE
Changing the material types used in your
equipment requires special attention to avoid
equipment damage and downtime.
• When changing materials, flush the equipment
multiple times to ensure it is thoroughly clean.
• Always clean the fluid inlet strainers after
flushing.
• Check with your material manufacturer for
chemical compatibility.
• When changing between epoxies and urethanes
or polyureas, disassemble and clean all fluid
components and change hoses. Epoxies often
have amines on the B (hardener) side. Polyureas
often have amines on the A (resin) side.
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