Most water jet cutting work pieces are thin sheets out of which flat shapes are cut, though gears and other complex shapes can also be cut by water jets. Depending on the equipment, a water jet cutter can deliver water streams at pressures anywhere between 30,000 and 90,000 PSI. The higher-pressure models are used in high pressure water jet cutting, which is used in the cutting of very strong work pieces.
Water jet cutting engineers choose water pressures depending on the qualities of the work pieces. Brittle or shatter-prone materials like glass, for example, are cut with lower-pressure streams to prevent breakage. Very strong metals like titanium or steel are more likely to be cut with streams at much higher pressures, and abrasive media may be added to the water stream to improve cutting efficiency.
Because almost every water jet cutting process is managed by computer numerical control (CNC), products emerging from water jet processing are sure to bear a near-perfect resemblance to their technical drawings.
In addition to producing products with extreme precision, water jet cutting machinery systems are highly efficient and safe alternatives to other cutting processes. Laser cutting, another popular cutting process, is also very precise and can be fully automated. However, it generates heat, sparks and fumes that can pose health and safety hazards to workers. It can also be extremely energy-intensive and inefficient.
Water jet cutting’s efficiency is due in large part to its reclamation system; all of the water and abrasive media expelled during the process can be collected and recycled, greatly reducing the consumption of water and abrasives. Also, compared to other cutting processes that involve heat, blades or other potentially hazardous equipment or conditions, water jet cutting is safe and requires few accommodations for worker safety, as no workers are near the water jet during its operation.
The major occupational hazard to consider in water jet cutting processes is noise, as the process can be very loud; a combination of personal ear protection and soundproofing can easily reduce that risk to workers.