How do I properly shut down, flush, and store my electric Graco Reactor?

Proper shutdown of your electric Graco Reactor is crucial for the reliability of your system and the quality of the spraying result.

Proper system shutdown, cleaning, and storage are critical for the safe and effective operation of your electric Graco Reactor spray foam proportioner. This step-by-step guide contains the information you need to shut down and store your system.

Note: This step-by-step guide walks you through shutting down and flushing for storing your machine. This document is not replacing the manual, for a full overview of safety instructions please see the manual.

Shutting Down

NOTICE: Proper system setup, startup, and shutdown procedures are critical to electrical equipment reliability. The following procedures ensure steady voltage. Failure to follow these procedures will cause voltage fluctuations that can damage electrical equipment and void the warranty.

  1. Press Stop Proportioner to stop the pumps.
  2. Turn off all heat zones.
  3. Relieve pressure (See Pressure Relief Procedure, manual page 60). 
  4. Press Park Pump to park the Component A Pump. The park operation is complete when green dot goes out. Verify the park operation is complete before moving to next step.
  5. Press the Startup/Shutdown button to deactivate the system.
  6. Turn off the air compressor, air dryer, and breathing air.
  7. Turn main power switch OFF.
    1. WARNING: To prevent electric shock do not remove any covers or open the electrical enclosure door while the power is ON.
  8. Close all fluid supply valves.
  9. Set PRESSURE RELIEF/SPRAY valves to SPRAY to seal out moisture from the drain line.
  10. Engage gun piston safety lock then close fluid inlet valves A and B.


WARNING: To help prevent fire and explosion:

  • Flush equipment only in a well-ventilated area.
  • Do not spray flammable fluids.
  • Do not turn on heaters while flushing with flammable solvents.
  • Flush out old fluid with new fluid, or flush out old fluid with a compatible solvent before introducing new fluid.
  • Use the lowest possible pressure when flushing.
  • All wetted parts are compatible with common solvents. Use only moisture-free solvents. 
  1. To flush feed hoses, pumps, and heaters separately from heated hoses, set PRESSURE RELIEF/SPRAY valves to PRESSURE RELIEF/CIRCULATION . Flush through bleed lines.
  2. To flush entire system, circulate through gun fluid manifold (with manifold removed from gun).
  3. To prevent moisture from reacting with isocyanate, always leave the system filled with a moisture-free plasticizer or oil. Do not use water. Never leave the system dry. (See Important Isocyanate Information, maunal page 7).

Refer to the manual for further directions:

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