The Pea in the Mattress

It may seem like a small detail, but tank orifice selection enormously impacts the efficiency of your processing time. Think of the tank orifice on your Comco blaster like the gears on a bike: the right gear conserves your energy. The right gear also maximizes your output for sustained energy and speed over a long, hilly ride. If you use a high gear to climb a steep hill, you risk collapsing into a puddle of sweat by the time you reach the top.

The tiny orifice at the bottom of your blaster tank meters abrasive into the air stream. Our patented modulated system fluidizes abrasive as it pulls from the tank. The blaster draws a small amount of this fluidized abrasive out of the tank at a rate of 50/60 times per second.

The goal of our modulated design is to create a consistent abrasive flow so you get consistent results. But, if the tank orifice is too small to accommodate abrasive particles, it may clog and turn a steady stream into a slow trickle. Conversely, if the tank orifice exceeds the size of the nozzle opening, abrasive may crowd in the stream and at the nozzle tip.

How to Select the Right Tank Orifice?

The tank orifice should be no smaller than 5x the average abrasive particle size and should not exceed the size of the nozzle opening. Two factors drive tank orifice selection:

  1. the abrasive particle-size
  2. the desired concentration of abrasive in the air stream

Practical examples

Are you…

  • blasting with 100 µ Aluminum Oxide? 
    • Use the MB1409-25 (.025″) tank orifice.
  • surface texturing or cleaning broad areas on a part?
    • Use a large* tank orifice since these applications use large nozzles and require greater working distance than most applications.
  • drilling holes or eroding material in tight spaces? 
    • Use a small* orifice. A large tank orifice permits a dense abrasive stream. Too many particles pushing through fill the features with abrasive, inhibiting the blasting process. A small orifice in this application proves to be cleaner and faster.

*Orifices sizes are relative to each blaster.

Use the chart below to guide tank orifice selection. For assistance, contact our Technical Sales Team via email or at 1-800-796-6626.

Tank Orifice Selection Chart

Dig Deeper

Comco MicroBlasting Nozzles and Abrasive Media - Brochure

Click here to access a complete list of nozzle and powder available from Comco.

Pat B, Sales and Marketing Manager


Email me or give me a call at 1-818-841-5500.