How a Worn Blast Nozzle Reduces the Speed of Abrasive

A common misconception is that you will save money by hanging onto your old blast nozzle

Sometimes we feel that we are actually going to save money by hanging onto our old blast nozzle as long as we can to get the most out of it.

The reality is that the actual cost of a blast nozzle is extremely small in comparison to the total project cost. It has been proved that the performance of a nozzle can actually affect your cost of blasting and your total project cost significantly. Our experience is that a new nozzle will pay for itself in under four hours of blasting!

How a blast nozzle works:

  1. Air/abrasive enters the nozzle and is compacted and increases speed as it passes though the orifice.
  2. From the orifice the air/abrasive enters the exit venturi section of the nozzle which widens out progressively.
  3. As the air travels along the exit venturi it expands increasing its speed significantly.
  4. As the air increases speed, so does the abrasive.

Therefore, if the nozzle is worn the abrasive cannot reach its maximum potential speed and full productivity is not reached. A new venturi nozzle actually speeds the abrasive up 2X the speed of a one where the venturi has been worn away.

Nozzle wear can be measured accurately with a nozzle size analyzer gauge. This enables you to know exactly when to replace your nozzle and not lose time and money.

We recommend the use of a nozzle size analyzer, the nozzle size gauge measures the orifice size of an abrasive blasting nozzle. Nozzle orifice wear leads to low nozzle pressure and results in decreased productivity and increased abrasive media consumption. It is good practice to check all the nozzles on a blasting job every week.

As soon as a nozzle has worn more than ½ a size, discard it and replace it with a new nozzle. Remember the cost of the nozzle is absolutely minimal compared to the money/time you will lose by continuing to blast with a worn nozzle.

Don't under estimate how significantly a worn nozzle will sap your productivity.

4 easy steps to determine blast nozzle wear using this convenient portable gauge.

Blast Nozzle Analyser With Pencil.jpg
Remove the marker from the cap of the gauge.
Blast Nozzle Analyser Marked DARK
Use the small black marker to colour a line on the side of the gauge.
Blast Nozzle Analyser With Nozzle.jpg
Now insert the gauge into the threaded end of the blast nozzle and twiste it.
Blast Nozzle Line
The nozzle orifice size is revealed by aligning the etched line in the black mark drawn on the side of the gauge to the scale on the gauge. Air consumption (CFM @ 100 psi) is also indicated.

Download the poster