The pressure of the pump, measured in PSI, will determine cutting speeds for a given orifice size and number of heads. All other things being equal, there is an almost direct correlation between pressure and cutting speed; higher pressure results in higher cutting speeds. From a practical standpoint, increasing pressure also results in higher pump consumable costs, so that must be weighed against the faster cutting speeds.

The following graph shows the cutting speeds for ½” (12 mm) stainless steel for a Quality 2 edge finish. The two lines represent two common combinations of orifices and abrasive nozzles. In each case, doubling the pressure from 30,000 psi (2068 bar) to 60,000 psi (4137 bar) results in an increase in linear cutting speed of approximately 2.9 times.

<b>IMPORTANT:</b> Keep in mind that pump horsepower is not always a direct indication of maximum pressure for the pump. A 200 HP pump may not necessarily have higher pressure than a 100 HP or 50 HP pump.