For applications like this, the water is mixed with abrasive particles made of garnet or diamond. As well, machines sometimes use high pressure jets to cut through hard substances.
Standard water jets have a constant stream of water that shoots out at pressures between 30,000 to 90,000 PSI. Some high pressure water cutters, however, have nozzles with jets as strong as 120,000 PSI, which propel water at twice the speed of sound. It also increases cutting speeds by up to 20 percent, thus quickening output times, which is important for applications where repeatability and mass production are applied.
Using high pressure in combination with abrasive particles to cut harder materials is a popular alternative to plasma cutting, sawing and welding. It produces a clean, smooth cut with no rough edges or burrs. Modern machines are fully automated and use CNC (computer numerical controlled) software that allows for high precision, accuracy and detail.
Assigning a computer to control a water jet cutting process not only ensures high levels of manufacturing precision, but it also reduces labor costs. Technical staff are only necessary for the setup, programming, monitoring and repair of equipment in many cases.
High pressure water cutting machines, which are referred to as ultra high pressure water jet cutters, obtain such high pressures by using intensifiers, which are pumps that use hydraulics to create extremely high pressure. Hydraulic systems harness the power of water moving at a fast pace and convert it to mechanical energy. To quicken the rate of the cutting process, many water jet cutters use multiple cutting heads. Most high pressure cutting machines have the ability to switch back and fourth between standard and high powered operation levels.
For those that operate mainly on ultra high pressure, cylinders and end caps are not threaded, which prevents the formation of cracks. The intensifier pumps use hydraulic accumulators that reduce wear and tougher center sections, piston seals and wear rings, which increase the machine’s lifespan and reduce the probability of leaking. High pressure machines tend to be much louder than standard water jet cutters, and are often equipped with a soundproof casing.