How high is your pressure?
Have you ever wondered what kind of pressure is generated by a waterjet cutting machine? Well, let me put it into perspective for you. Your run of the mill car tire gets inflated to about 2 bar. A diving cylinder for scuba has a working pressure of about 230 bar. An industrial high-pressure cleaner operates at about 300 bar.
The Hyplex Prime direct drive pump that we use is rated at an impressive 4150 bar! Now imagine forcing water at that pressure through a tiny hole with a diameter of only 0.3 to 0.4 mm. Yes, that is how you manage to cut through steel of up to 200 mm thick!
The Flow ultra-high pressure waterjet pump
The interesting thing though, is that it is not really the water that does the actual cutting, but the abrasive that is mixed with the water as the water exits the orifice at high speed (±960m/s). The density of water is too low to effectively cut hard materials as the energy is absorbed or reflected. With the introduction of an abrasive inside a mixing chamber, the abrasive sand is accelerated by the water and therefore the energy it transferred to the abrasive. The abrasive has much more momentum due to it density and the transfer of momentum effectively cuts the steel.
The most popular abrasive that is being used for waterjet cutting is garnet due to its high hardness and correct density. At Waterjet Cape Town we only use the highest quality alluvial garnet imported from GMA Australia.
Abrasive garnet for waterjet cutting
