The next step in determining which pump is appropriate for your application is to determine the types of material you will be cutting and how many cutting heads you want to be able to run at one time.

If you are cutting parts out of foam, wood, cardboard or other soft materials, then you would be dealing with a pure water application. For pure water applications, a 30 HP pump is usually sufficient. As you can see from the previous Orifice Selection chart, up to three cutting heads could be used with 0.006” orifices.

If more cutting heads were needed, then a 50 HP pump could handle up to five cutting heads with 0.006” orifices. For abrasive applications, the 50 HP is the general starting point. With this pump, you can run one head with a 0.014” orifice or two heads with 0.010” orifices. The 0.010” orifice will perform exceptionally well with respect to speed and cut quality on thinner material (1/2” and under).

The following graph shows cutting speeds for single head versus dual head cutting in ½” stainless steel. As thickness get beyond 2” (50 mm), the absolute difference in cutting speeds between the nozzle combinations starts to decrease more dramatically.

Cutting with two heads with 0.010” orifices effectively doubles the cutting speed (2 x 5.5 ipm) versus cutting with one head with a 0.010” orifice. Compared to cutting with one head with the 0.014” orifice, cutting with two heads will increase output by about 20 percent. To put this concept into real world terms, it would be like if you started cutting on a job on Monday morning with two cutting heads, then you could get it to your customer by Thursday afternoon. If you cut the job with one head, your customer wouldn’t get the part until Friday afternoon.

For someone looking to cut thicker materials on a consistent basis, then we would suggest allocating 50 HP per cutting head. If you selected a 100 HP pump, you could run two heads with 0.014”.

If you are cutting very small parts in high volumes, you might want a very large cutting table where you could run four cutting heads and quadruple your production over a single-headed system. In that case you would likely choose the 150 HP pump that can run four heads with 0.013” orifices.