High Pressure Equipment Flushing

As the temperature starts to rise and more jobs roll in, it's time to perform spring maintenance on your equipment to get ready for the busy season ahead. This is especially important for those of us that live in a climate with long winters, the slow down in work can leave your equipment sitting idle between jobs resulting in crystallized isocyanates forming in the system.

Getting crystals in your spray foam equipment or material can cause a whole host of expensive problems and a lot of lost time. Even small crystals can stop your spray application in its tracks. This tech tip is designed to give an overview of how to flush your high pressure equipment of polyurethane foam or polyurea coating chemicals as part of a regular maintenance schedule.

For the flushing procedure we will use All-Solve which is especially effective for cleaning the proportioner, transfer pumps and hoses, as it quickly and completely cleans polyols, crystallized isocyanates, and other urethane intermediates.

For long term storage of the equipment we will fill the system with Pump Fluid which is a highly refined, special purpose lubricant that can be used for equipment flushing, equipment storage and throat seal lube.

We recommend all applicators follow this procedure every 6 to 12 months. This will help to prevent the build up of contaminants in the system that can clog filters and cause off ratio issues.

What you will need:

• All-Solve - 5 to 10 gallons - All-Solve is especially effective for cleaning the proportioner, transfer pumps and hoses, as it quickly and completely cleans polyols, crystallized isocyanates, and other urethane intermediates. Learn More
  
• Pump Fluid - 5 to 10 gallons - Pump Fluid is a highly refined, special purpose lubricant that can be used for equipment flushing, equipment storage and throat seal lube. Learn More
  
• Empty 5 gallon Pails - 4 to 6 - The empty 5 gallon pails are used to separate the fluids for use with either A-side or B-side of the proportioner.

Flush Procedure

Step 1 - Disconnect hoses from gun. Follow your equipment's Pressure Relief Procedure before cleaning, checking, or servicing equipment.

Step 2 - We will begin by air purging all of the material from the Resin side of the system.

Step 3 - Close the transfer pump air line needle valve, disconnect the air line from the Resin transfer pump and remove the pump from the material drum. If possible lift the inlet ball to drain the material from the transfer pump. Wipe the exterior of the pump with a clean rag.

Step 4 - Insert the Resin transfer pump into an empty pail and secure to prevent tipping. Reconnect the air line.

Step 5 - Using just the transfer pump slowly open the transfer pump air line needle valve and purge the material back into the drum the material came from (This will purge all the Resin from the system and fill the system with air allowing us to save most of the material in the system). Once all material has been purged from the system close the transfer pump air line needle valve and disconnect the air line on the Resin transfer pump.

Step 6 - We now need to repeat this procedure (Steps 3 – 5) to purge all of the material from the Iso side.

Step 7 - Now that the fluid has been air purged from the system we can start the cleaning procedure. Fill two separate 5 gallon pails with 2-4 gallons of All-Solve (1 pail for the (A) Iso side and 1 pail for the (B) Poly side). All-Solve is especially effective for cleaning the proportioner, transfer pumps and hoses, as it quickly and completely cleans polyols, crystallized isocyanates, and other urethane intermediates.

Step 8 - Insert each transfer pump into separate 5 gallon pails of All-Solve and secure to prevent tipping the pails. Reconnect the air lines. Slowly open the transfer pump air line needle valve and fill the system with All-Solve. Purge the first 1/2 gallon of material per side into a waste pail. Safely dispose of the waste materials in accordance with federal, state/provincial and local regulations.

Step 9 - Once the proportioner has been filled with All-Solve you can turn on the proportioner and set the primary and hose heaters to 150° F and turn on the heaters (Do not attempt to pressurize the system).

Step 10 - Securely fasten the material hose ends to their respective pails of All-Solve, use a filter/screen under the material hose ends if you suspect debris to be in the system, open the transfer pump air line needle valve and allow the All-Solve to recirculate through the system for 2-4 hours or longer depending how much scale has built up on the inside of the system.

Step 11 - Once the cleaning procedure has finished we will need to air purge the All-Solve from the system.

Step 12 - Insert the transfer pumps into an empty pail and secure to prevent tipping. Reconnect the air line.

Step 13 - Using just the transfer pump slowly open the transfer pump air line needle valve and purge the All-Solve back into the 5 gallon pail it came from (the All-Solve can be saved and used again to flush the system at a later date).

Step 14 - Once all the All-Solve has been purged from the system close the transfer pump air line needle valve and disconnect the air line from the transfer pump.

Please choose from the following 2 options.

1 - Go Back To Spraying

Step 15 - Wipe the exterior of the transfer pumps with a clean rag. Insert the transfer pumps into their respective material drums and secure. Reconnect the air lines.

Step 16 - Slowly open the transfer pump air line needle valve and fill the system with Iso and Resin. Purge the first 1/2 gallon of material per side into a waste pail. Safely dispose of the waste materials in accordance with federal, state/provincial and local regulations.

Step 17 - Re-attach the spray gun to the hoses, turn on the proportioner, set the temperatures and pressures according to the material specifications.

Step 18 - Spray onto piece of cardboard or other disposable surface to insure material is spraying and curing correctly. You are now ready to spray.

2 - Put The Proportioner Into Storage

Step 15 - Fill two 5 gallon pails with 2-4 gallons of Pump Fluid, a highly refined, special purpose lubricant that can be used for equipment flushing, equipment storage and throat seal lube.

Step 16 - Wipe the exterior of the transfer pumps with a clean rag. Insert the transfer pumps into separate 5 gallon pails of Pump Fluid and secure to prevent tipping the pail. Reconnect the air lines.

Step 17 - Slowly open the transfer pump air line needle valve and fill the system with Pump Fluid. Purge the first 1/2 gallon of material per side into a waste pail. Safely dispose of the waste materials in accordance with federal, state/provincial and local regulations.

Step 18 - Securely fasten the material hose ends to their respective pails of Pump Fluid, open the transfer pump air line needle valve and allow the Pump Fluid to recirculate through the system for 15 minutes.

Step 19 - Re-attach the spray gun to the hoses, turn the proportioner on and increase pressure to 1000 psi. Trigger spray gun until pump is in the park/retract position and pressure falls below 500 psi.

Step 20 - Insure all valves are closed and power is off. Remove and clean spray gun. The proportioner can now be safely stored.