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

Proper shutdown of your hydraulic 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 hydraulic 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 up 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 55).
  4. Press Park Pump to park the Component A and Component B pumps. The park operation is complete when the green dot goes out. Verify the park operation is complete before moving to the next step.
  5. Press Startup/Shutdown button to deactivate the system.
  6. Turn off the air compressor, air dryer, and breathing air.
  7. Turn the main power switch OFF. 
    1. WARNING: To prevent electric shock do not remove any shrouds 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 avoid fire and explosion: 

  • Flush equipment only in a well-ventilated area.
  • Ensure the main power is off and the heater is cool before flushing.
  • Do not turn on the heater until fluid lines are clear of solvent.
  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 the entire system, circulate through gun fluid manifold (with manifold removed from the 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 Two-Component Material Information, manual page 7).

Refer to the manual for further directions:

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