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How a Water Jet Machine Works

How Waterjets Work

Waterjets cut with a supersonic stream of water that is so powerful it can cut through materials in one pass without shredding or crushing them. The Jet Edge water jet is created by pressurizing water up to 90,000 psi (6,200 bar) with a Jet Edge waterjet intensifier pump. The waterjet cutting action takes place as a result of the ultra-high pressure (UHP) water being forced through a pre-mounted waterjet orifice as small as .005 inches. In many applications, an abrasive material such as waterjet garnet is added to the waterjet to create an abrasive waterjet (also known as an abrasivejet) that can cut cleanly through virtually any material.

Abrasive Waterjet System - Precision Cutting

Jet Edge waterjet system

Mobile Water Jet System

Mobile Water Jet System

Powering the Waterjet - The Waterjet Intensifier Pump

The waterjet intensifier pump acts as an amplifier as it converts the energy from the low-pressure hydraulic fluid into ultra-high pressure water. The hydraulic system provides fluid power to a reciprocating piston in the intensifier center section. A limit switch, located at each end of the piston travel, signals the electronic controls to shift the directional control valve and reverse the piston direction.

The intensifier assembly, with a plunger on each side of the piston, generates pressure in both directions. As one side of the intensifier is in the inlet stroke, the opposite side is generating ultra-high pressure output. During the plunger inlet stroke, filtered water enters the high pressure cylinder through the check value assembly. After the plunger reverses direction, the water is compressed and exits as ultra-high pressure water and then enters the pressure vessel (attenuator). The attenuator smoothes pressure fluctuations from the intensifier and delivers a constant and steady stream of ultra-high pressure water to the cutting or cleaning tool.

Waterjet Intensifier Pump Animation

intensifier pump animation

Frequently Asked Questions about Waterjets

What is the difference between waterjet and abrasive waterjet (abrasivejet)?

"Waterjet” is commonly used to reference both water-only water jet and abrasive water jet (abrasivejet) cutting. Water-only water jets cut with ultra-high pressure water alone. Abrasivejets cut with an abrasive material (usually garnet) that has been added to the water stream. Water-only waterjets can cut through softer materials such as food, rubber and foam. Abrasive waterjets are used to cut through harder materials such as plastic, composites, stone and metals.

What is the difference between an intensifier and a crankshaft/direct-drive pump?

A crankshaft or direct-drive style pump uses a crank to drive the waterjet pump’s plunger, while an intensifier uses a hydraulic cylinder to drive the plunger. Intensifier pumps cost somewhat more upfront, but pay for themselves over time with lower maintenance costs and longer service life. Jet Edge has customers who have logged more than 35,000 hours on waterjet intensifier pumps that are still going strong. For more information, please see our Precision Waterjet Intensifier Pump Brochure.

What can be cut with Jet Edge abrasivejet/waterjet?

Virtually anything! Materials commonly cut with waterjet include rubber, foam, plastics, composites, stone, tile, metals, food, paper and much more. The only materials that cannot be cut with waterjet are tempered glass, diamonds and certain ceramics.

How is waterjet cutting motion controlled?

Jet Edge waterjet/abrasivejet cutting systems are controlled by PC-based motion control systems that can accept any CAD files.

What tolerances can waterjets hold?

Waterjet systems generally hold tolerances of +/-0.001" to 0.005" (0.025mm to 0.127mm). 70% of the industry cuts at +/-.010" or greater.

How much training is required to learn how to run a waterjet machine?

An operator with no experience whatsoever should be able to learn how to operate and maintain a waterjet cutting machine with as little as one week of training. New CAD/CAM nesting programs such as the SigmaNEST™ Companion software offered by Jet Edge make it possible for an operator with no programming experience to program the machine with only a few hours of training.

How much routine maintenance is involved? Can an average shop worker maintain a waterjet machine?

As with any machine tool, waterjet systems require routine maintenance to ensure lasting performance. With a day or two of training, a waterjet operator of average skill level should be able to perform basic maintenance tasks such as replacing nozzle parts and pump seals. When selecting a waterjet manufacturer, make sure they offer lifetime water jet maintenance training.

How thick of material will abrasivejet cut?

Jet Edge has cut metals as thick as 20 inches, including 15” titanium, with abrasive waterjet.

How much water do Jet Edge waterjets use?

Jet Edge waterjet systems use a half gallon to approximately one gallon of water per minute depending on the cutting head orifice size. The water can be recycled using a closed-looped system. Waste water usually is clean enough to filter and dispose of down a drain.

Is water treatment necessary?

Before installing your Jet Edge water jet system, we recommend that you have a water quality analysis performed by a commercial company that specializes in water conditioning equipment. They can recommend the most suitable equipment for your specific water conditions. Inlet water should be treated for either the removal of hardness or the reduction in Total Disolved Solids (TDS). A water treatment producing TDS content of less than 0.5 ppm is not recommended since the aggressiveness of the purified water may damage the intensifier pump components. Treated water must have a pH value of 6 to 8.

  • If your water has low TDS (<100 ppm), it can be treated by softening alone.
  • If your water has moderate TDS (100-200 ppm), it can be treated by softening, deionizing (DI) or reverse osmosis (RO) equipment.
  • If your water has high TDS (>200 ppm), water quality is considered poor and should be treated with DI or RO equipment.
  • If your water has high silica concentration (>15 ppm), dual strong-base DI is recommended.

How much water jet garnet does abrasive waterjet (abrasivejet) use?

Abrasive waterjets use approximately 0.5 to 1.5 pounds (0.25 to 0.68 Kg) of abrasive per minute. Garnet can be recycled or disposed of in a landfill.

What do you do with used waterjet garnet?

Waterjet Garnet is a non-toxic natural substance that can be recycled for repeated use using a Jet Edge Waterjet Abrasive Recycling System.  Spent water jet garnet usually can be disposed of in a landfill.

How much does it cost to run a waterjet system?

A typical abrasivejet costs about $19-35 per hour to run per nozzle depending on horsepower, plus labor. This includes consumable parts, garnet, water and electricity. Utility costs vary depending on your location.

What Can be Cut with Jet Edge Waterjet/Abrasivejet

Virtually anything can be cut with Jet Edge waterjet or abrasivejet! Here are a just a few examples of what you can cut with your Jet Edge waterjet/abrasivejet cutting system.

  Water Jet Cutting 6.5" titanium
Soft Rubber
Hard Rubber
Soft Gasket Material
Paper and Cardboard
Carbon Fiber
Reflective Metals
Hardened Tool Steel
Mild Steel
Stainless Steel
Exotic Materials
Food Products
Much, Much more
Water Jet Cutting Titanium


I have heard that waterjets can delaminate some materials. Can this be prevented?

Waterjets can delaminate some materials such as fiberglass. In many cases, this can be prevented by low-pressure piercing or pre-piercing the material with a pneumatic drill prior to waterjettting. If this is a concern, ask your prospective waterjet manufacturer to perform a test cut on your material.What are some ways to increase productivity with a waterjet system?

There are many ways to increase productivity with waterjets.  You can add multiple cutting heads, you can buy an intensifier pump with higher horsepower, you can stack materials, and you can tightly nest parts to get more parts out of a sheet of material. The biggest gain in productivity in recent years has been the emergence of “hyper-pressure” waterjet intensifier pumps, such as Jet Edge's X-Stream xP90-100 intensifier pump. These pumps are capable of producing pressures as high as 90,000 psi and can double the cutting speed for many materials.

Why should I use waterjet or abrasive waterjet versus conventional cutting methods?

Cut Without Heat
Jet Edge waterjet technology is ideal for cutting heat sensitive material. Costs due to thermal distortion of machine parts are eliminated. Risk of fatigue failure resulting from process induced thermal stressing and associated material structural change is minimized.

Accurate Cutting
Jet Edge waterjets can hold an accuracy of 0.005 inch with a repeatability of 0.001 inch over the entire work envelope.

No Sharpening Required
Unlike conventional cutting tools, waterjets cut with a supersonic stream of water that never dulls. With waterjet, you will never need to shut down to sharpen or clean blades.

Minimize Dust and Toxic Fumes
The practical elimination of airborne dust particles, smoke, fumes, and contaminates from cutting materials such as asbestos and fiberglass greatly improves the work environment and reduces problems arising from operator exposure.

No Finishing Operation Required
Selection of appropriate cutting parameters such as operating pressure, material feed rate, abrasive particle size, and flow rate can eliminate the need for secondary operations. Jet Edge systems also reduce machining time and production costs.

Non-Contact Cutting and Cleanliness
USDA approved equipment designs promote the use of ultra-high pressure waterjet streams in the sanitary cutting of food products. Using UHP waterjet results in higher cutting speeds and the elimination of associated downtime incurred for cleaning and resharpening delicate blades. One of the biggest advantages is that fixturing associated with other machining methods is minimized.

Near Zero Lateral Cutting Force
Jet Edge waterjet systems reduce fixturing costs plus avoid excessive stress to finished parts. Also, minimal lateral force simplifies material handling and allows cutting close to material edges.

Minimum Waste Material
With typical orifice diameters in the range of 0.003 – 0.030 inches, waterjet kerf width is kept to a minimum, thus maximizing material utilization.

Omni-Directional Cutting
Waterjet cut profiles are not confined to straight-line geometries. Part complexity is limited only by the motion control system specified and traditional start holes are eliminated.

Environmentally Friendly
Waterjets produce no hazardous waste, reducing waste disposal costs.  They can cut off large pieces of reusable scrap material that might have been lost using traditional cutting methods.  Parts can be closely nested to maximize material use, and the waterjet saves material by creating very little kerf.  Waterjets use very little water (a half gallon to approximately one gallon per minute depending on cutting head orifice size), and the water that is used can be recycled using a closed-looped system.  Waste water usually is clean enough to filter and dispose of down a drain.  The garnet abrasive is a non-toxic natural substance that can be recycled for repeated use.  Water Jet Garnet usually can be disposed of in a landfill.