Section 3: Using the MicroBlaster
MicroBlaster MB1005
Comco Inc.
3-6
Issue Date: September 2003
Tank Orifice
The powder tank is fitted with a single orifice at the bottom through which all powder
must pass (see Figure 3-1). The amount of powder flowing is directly proportional to the
size of this opening.
As seen in the table below, a small increase in the diameter of the tank orifice results in
a large increase in the area of the opening. In other words, increasing the tank orifice by
only a few thousandths of an inch, can almost double the amount of powder that will
pass through it and out the nozzle. This is a very important factor, since the number of
abrasive particles striking the work surface has a direct relation to the speed of the
cutting action.
Diameter, in.
Area, in
2
.
Comco P/N
0.018
2.5 X 10
-4
MB1409-18
0.025
4.9 X 10
-4
MB1409-25
0.030
7.1 X 10
-4
MB1409-30
0.040
12.6 X 10
-4
MB1409-40
0.060
28.3 X 10
-4
MB1409-60
Some judgment is required in selecting an orifice. A very small orifice should not be
used with powders of large particle size. Likewise, a very large orifice may cause a
small nozzle to plug from excessive powder in the line. See Table 3-3 for guidelines in
selecting orifice size.
The MB1005, as shipped from the factory, is equipped with the 0.040" diameter orifice
(MB1409-40). Additional orifices are provided in the accessory parts kit. The orifice will
have a number stamped on the side that corresponds to the dash number, and opening
size. Refer to the table above to determine the size. The tank orifice should be installed
finger tight only with a 1/4” nut driver (see Figure 3-1).
For improved performance and longer life, all Comco orifices are carbide lined.
Rev. 5/14
