Safety Alert: Steps to Safely Remove a Blockage

Sadly, there was a recent fatality involving an operator who attempted to remove a blockage using compressed air. PLEASE forward this email to all your operators as a reminder to NEVER use compressed air when attempting to remove a blockage.

If You Plug:

  • Clear the discharge area!
  • Rock the plug back and forth, using forward-reverse of the pump. If the plug doesn’t release, reverse the pump for several strokes to relieve all line pressure, then stop the pump.
  • Do NOT jam the blockage. This will only force the finest material through the plug, making a bigger plug behind it.
  • NEVER use compressed air to remove a blockage. Not EVER.

Relieve pressure by reverse pumping before opening any pipeline or hose components.

Finding the Blockage:

  • After relieving pressure, step on the hose to find the unyielding area, or tap on the pipe lightly with a metal tool. The area with the plug will sound different than the rest of the pipe because the tightness of the plug will keep the metal from vibrating at that spot. Do NOT bang on either a pipe or a hose with a hammer. It will damage the pipe or hose and wear out at that spot.
  • After locating the blockage, remove the plugged piece of system, elevate one end, dislodge the plug and shake it out. Do not assume that the first thing that falls out is all of the plug. Do not re-hook the system until all of the plug is removed.
  • Clear the discharge area before you resume pumping. There will always be air in the system after rocking a plug or removing a blockage.

One difference between concrete and air is that air is compressible meaning it stores energy while concrete does not. This situation creates the potential for a very dangerous release of energy. Meanwhile, the air pressure isn’t high enough to help remove the blockage. An air compressor produces only 150 psi while a concrete pump produces over 1,000 psi. If the pump can't push it, air never will.

Remember…NEVER use compressed air to remove a blockage!

Resource: ACPA Operator Safety Presentation 5.0

The information above is the official position of the American Concrete Pumping Association regarding "Safety Steps to Remove a Blockage" but does not supersede manufacturer recommendations.