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June 2016 - Field Service Technicians Offer Preventative Maintenance Tips

June 2016- Field Service Technicians Offer Preventative Maintenance Tips

Maybe you have a gasket in your extruder hood leaking from harsh cleaning chemicals, or product is building up in a bin because your airlock is causing a loss in pressure due to a rotor rubbing an end plate, or you have a plug in your line due to excessive pressure build up in a vessel. Whatever the reason, it’s inevitable that things break. A minor problem can actually become a major issue for your convey system because it can cause a chain reaction where one problem affects the whole system. So instead of waiting to fix something when it breaks, use these preventative steps to keep things running as smoothly as possible. Here are just a few of our maintenance tips to check for when it comes to preventing issues with your Extruder hood, Airlocks or Pressure/Vacuum Fans.

Extruder Hood

  • Periodically inspect the seals at the clamshells and replace the seals when needed.
  • Periodically inspect the seals on the bypass gate assembly and replace the seals when needed.
  • Clean observation windows to allow for clear view of product lifting from the die.
  • On a regular basis, inspect and drain the compressed air filter on the compressed air supply.
  • Consistently check the Magnehelic gauge for pressure readings which may be too high or too low.
    • Make sure gauge is zeroed when not in production. Check the tubing leading to the extruder hood. Disconnect the tubes at the gauge and clear with compressed air. Look for loose fittings, cracked, broken or pinched tubing.
    • Inspect the ductwork to and from the extruder hood for air leaks or blockage. Make sure that any dampers in the systems are correctly positioned to allow proper air flow through the hood.


  • Every 3 months or after 2,500 operating hours:
    • Visually inspect to confirm that valve turns smoothly.
    • Confirm that air purge is functioning by ensuring that the solenoid controlling the air purge is turned on when the airlock is on. The air purge should be set at 2 to 3 psi higher than the highest convey pressure. This can be adjusted via an air regulator, and the best way to check for that value is to look at the pressure gauge on the blower.
  • Every 12 months or after 10,000 operating hours:
    • Completely clean airlock.
    • Check packing/lip seal for damages. Replace if necessary.
    • Check rotor blades for wear or damage. Repair if possible or replace.

Pressure and Vacuum Fan

  • Periodically check the fan wheel for any wear, corrosion or buildup of material. Clean or replace the wheel as required.
  • Periodically check the V-belt drive for proper alignment and tension. If belts are worn, replace them as a set.
  • Lubricate the bearings.
    • Use the table for lubrication scheduling according to operating speed and shaft diameter. Bearings should be lubricated with a premium quality lithium-based grease conforming to NLGI Grade 2.
    • Add grease to the bearing while running the fan or rotating the shaft by hand. Be sure all guards are in place if lubrication is performed while the fan is operating. Add just enough grease to cause a slight purging at the seals. Completely filled bearings will run hotter until a sufficient amount of grease is purged out of the seals.

Bearing Lubrication Interval Chart

It’s also a great idea to keep a spare parts inventory in case something breaks down and you find yourself in an emergency situation. HorizonPSI has a department dedicated to airlock inspections and rebuilds as well as access to new valves. Please call our Service Solutions Group at (785) 842-1298, and they’ll be happy to assist you with ordering your part or component.

At HorizonPSI, we understand your process must work for you to be successful, and we are committed to safety and stand behind our service. Our Field Service Technicians are experienced and knowledgeable as well as OSHA trained. If you’d like to talk with a technician or schedule an on-site audit or evaluation, please contact Kent Lauridsen, Vice President of Engineering, at (785) 856-8139 or