Water Jet Cutter Safety Part 1: The Motion System

Workplace safety focuses on identifying, preventing, and eliminating hazards that cause accidents or negatively impact worker health. The Occupational Safety and Health Administration (OSHA), part of the United States Department of Labor, sets safety standards that organizations must satisfy. Adhering to these standards is crucial for maintaining a safe working environment.

Safety First

Anyone who operates equipment is responsible for adhering to the safety precautions and operating procedures detailed in the equipment owner’s manual and the company’s safety policies. Proper training ensures operators are proficient in these safety practices. Improper equipment operation and maintenance can create hazardous conditions, resulting in death, injury, and equipment damage. Before using your water jet equipment, ensure you have received comprehensive training and have read and understood your product manuals. Highlight any safety information contained in them.

While there are many financial and reputational benefits to following robust safety protocols and complying with regulations, the best reason is that the safety and wellbeing of your employees should be your number one obligation.

⚠️ Warning: This blog is only intended to provide an overview of safety tips when operating a water jet. Consult your owner’s manual and your company’s safety manual prior to operating or performing service on your water jet system.

Water Jet Cutting Hazards - The Motion System

A complete water jet cutting system many components, each with unique safety protocols. This blog will focus on water jet motion systems and outline important safety practices intended to protect your operators from injury.

The motion system is the water jet cutting tool component that receives an ultra-high-pressure water stream delivered through high-pressure water lines from a remote pump. This high-pressure water is converted to a highly focused “jet” at the cutting head for precise cutting and machining of the stock material.

Don’t be fooled by the word “water.” In the context of a water jet, it refers to the output generated by a 60,000 psi (4,100 bar) ultra-high pressure pump capable of producing water velocities up to 2,000 mph (3,300 kph). Water jet cutters can easily slice through materials like titanium, stainless steel, and aluminum – all of which can be several inches thick. As you can imagine, this kind of power can be extremely dangerous if the proper safety protocols are not always followed before, during, and after operation.

Motion System Installation

Your OEM should provide a factory technician to set up the motion system and connect the ancillary components. As the purchaser, you will usually be responsible for contracting riggers to place the equipment as well as engaging certified electricians to connect high voltage electrical wiring. You’ll also be responsible for providing maintenance resources to provide inlet water and compressed air.

Key motion system installation criteria include:

The motion system should be installed in a location that is well lit and ventilated, free of atmospheric hazards such as gas, vapors, or dust in explosive concentrations. Refer to the National Electric Code (NEC), OSHA requirements, and local codes for detailed information about environmental criteria.
Floor material must be concrete, capable of supporting the weight of the machine, and thick enough to provide resistance to vibration. The floor must allow for the motion system to be leveled.
Clearance must be provided around the machine to permit safe operation and access for routine maintenance, repairs, and for connecting the various water and electrical lines.
Required shop utilities include electric power, low-pressure process water, filtered dry air supply, and drainage. The pump should be in close proximity to minimize installation costs.
The jet stream produced by the pump needs to be routed to the motion system via specialized high pressure tubing and tubing fittings rated for the pressure the pump is operating at for both safety and performance.

Your OEM factory technician will ensure all components are installed correctly and working as part of the installation. The complete system will be fully tested to ensure it has been installed correctly and delivers the performance as expected. Initial training on safety and operations should be provided at that time as well.

Prior to Operation

For maximum safety, all operators must receive comprehensive training before powering up the motion system. Best safety practices prohibit the operation of the motion system until all necessary training has been completed successfully or the operation is under the direct supervision of a competent, trained individual.

Key preparation steps before turning on the water jet tool include:

Review the manufacturer’s product manuals and highlight all applicable safety information for quick and easy reference later.
Familiarize yourself with the motion system’s operating procedures and ensure you understand all controls.
Ensure the work area around the equipment is clean, dry, and free of any hazards that may cause trips or falls.
Ensure no employees or bystanders not involved in operating the equipment are at a safe distance before cutting begins.
Locate all emergency stops to enable quick shutdown of operations in case of an emergency.
Confirm you have all required personal protective equipment (PPE) available and are trained in their proper use.
Adhere to all safety practices detailed in your company’s safety policy and use common sense to minimize and eliminate operational risks. If something doesn’t look or seem right, get clarification before proceeding.
If you identify any issue that could create a safety risk, stop operation immediately and consult your safety team before proceeding.

Protective Gear (PPE)

Wearing appropriate personal protective equipment (PPE) is non-negotiable when operating a water jet cutter – no gear means no operation allowed. The high-pressure water stream can produce powerful ricochets upon contacting stock, hold-down fixtures, or slats. These ricochets may contain water, abrasives, or stock debris that can injure eyes, cut skin, or be inhaled.

Always wear safety goggles or face shields to protect against flying debris.
Wear hearing protection, as water jet cutters can generate noise levels above 85 dB, leading to hearing loss with prolonged exposure. Best sound-dampening practices recommend keeping the water level in the catch tank high enough to touch the workpiece. If your water jet has a bladder tank that allows for submerged water jet cutting, using this capability significantly reduces noise levels.
Ensure the use of respiratory protection as airborne particles are present. Proper ventilation is essential to disperse particles. Side shields can help reduce (but not completely eliminate) particle exposure. Remember, prolonged exposure to airborne particles can cause respiratory health problems.

Safety During Cutting Operations

The motion system moves before, during, and after the cutting process. Awareness of moving parts is critical to avoid contact and potential injury. Only fully trained operators should perform water jet cutting by themselves. Less experienced operators should be adequately supervised until they are proficient in all aspects of the cutting tool's operation.

It is also essential to thoroughly understand the stock material’s properties and how it reacts to the cutting process. Operators must understand the proper material fixturing or hold-down methods, required pump pressures, and whether they will perform water-only or abrasive cutting.

Check your PPE for proper fit and function and ensure everyone in the area is similarly protected. Do not remove any piece of your PPE while the water jet is operating.

Always Begin Each Shift with a Basic Inspection

To ensure a complete inspection is performed prior to shift start, create a waterjet inspection checklist. Have the individual performing the inspection confirm each step has been performed by initialing each step, dating the form and signing.

Ensure all cabinet doors are closed and secured during operation.
Verify that the work area around the motion system is free of obstructions that could cause trips or slips.
Check your PPE for proper fit and function and ensure everyone in the area is similarly protected. Do not remove any piece of your PPE while the waterjet is operating.
Locate the emergency stop(s) and confirm it is in the operating position.
Check that the catch tank is full of water and remove any debris accumulation.
Ensure that the hand valves controlling the flow of ultra-high-pressure water to the tools are open.
Activate power to the controller and ensure software loads properly.
Activate power to the intensifier pump and confirm pressure levels
Inspect the motion system, intensifier pump, and high-pressure components for water leaks. Remember to use cardboard rather than your hand when inspecting for leaks. If a leak is detected, repair the machine before returning it to service.
Ensure that nothing obstructs the movement of the water jet cutting tool or the travel of the ultra-high-pressure whip and swing arms that supply this water to the z-axis assembly.

Potential Operational Hazards to Avoid

When wet, the floor around the catch tank can become slippery, creating a slip-and-fall risk. Clean up any water around the tank and use non-skid rubber mats. Always wear appropriate footwear and remain vigilant of your footing.

Pressurized fluid streams can easily penetrate the skin, causing severe personal injury. Keep your hands and body away from pinholes and nozzles that eject or are capable of ejecting fluids under high pressure. Use a piece of cardboard, not your hand, when checking for leaks.

High voltage is present! Contact with high voltage, especially in the presence of water, can result in a severe shock (at best) or even death. Keep all covers closed while the water jet and its ancillary equipment operate. Studies show voltages as low as 42 volts and currents as low as 20 mA can have adverse effects and cause death.

Some machine components will move while the equipment is operating. You must remain aware of component movement so you don’t come into contact with it. Keeping clothing and hands away from the equipment is especially important, and always verify that covers and shields are in place before starting the machine.

Performing a Dry Run (Trial Run)

The dry run feature executes the part’s cutting program’s axis movement with the cutting heads turned off. Typically set to run the program as fast as is practical, it helps validate the programmed tool path and allows for adjustments to feed rates, dwell times, and other program parameters to optimize cut execution. It also verifies that the cutting head never contacts the workpiece and stays within the cutting boundaries.

Routine Maintenance

Adhering to the routine maintenance schedule your water jet’s manufacturer recommends is essential for ensuring all components function correctly. Critical maintenance practices include:

Keep the System Clean

Component cleanliness is a primary factor in proper machine performance. Contamination from hydraulic fluid, water, abrasives, etc., can lead to significant equipment failures. Use a damp cloth to remove grit and dirt accumulations on the cross beam, side beams, and z-axis assembly. Frequently rinse the cloth in clean water to avoid recontamination. Ensure thorough cleaning of the equipment after each use.

Keep the System Lubricated

Tool movement relies on servomotors, ball screws, ball nuts, and linear bearings in the cross beam, side beams, and z-axis assembly. As specified in your water jet owner's manual, these components require regular cleaning, inspection, and lubrication. Use only manufacturer-recommended lubricants and avoid applying lubricants unless they match the type and grade already in use.

Ensure Working Order

Visual inspection before operation goes a long way to ensuring your water jet operates correctly and as expected. Here are the steps recommended for this safety procedure:

Confirm the cutting head and orifice are sized according to job requirements and are free from damage.
Inspect the motion system, intensifier pump, and high-pressure components for water leaks. Remember to use cardboard rather than your hand when inspecting for leaks. If a leak is detected, repair the machine before returning it to service.
Check the intensifier pump for any hydraulic leaks (cardboard is best here, too) and ensure the hydraulic reservoir fluid level is correct.
Ensure the catch tank is full and the slats are level and undamaged.

Equipment Service Intervals & Repairs

Service procedures should only be performed by individuals experienced in servicing water jet systems and familiar with all operational aspects of the motion system, remote pumps, high-pressure lines, and any installed accessories or options.

When servicing the motion system, always lock out and tag the electrical switch, following OSHA guidelines, to prevent the machine from being turned on during maintenance unless power is required for a maintenance or service procedure.

Always wear appropriate PPE when performing service.
Turn the machine off before starting maintenance procedures.
Keep a record of all maintenance and service performed.
Use lock-out tag out safety practices when disconnecting electrical power or ultra-high pressure water.
Before disconnecting any water line, verify that the ultra-high water pressure is at zero pressure.
Special tools designed to prevent damage to components and ease the task may be required to properly repair some components.
Ultra-high pressure (UHP) lines and connections must be rated to the maximum pressure being cut at and installed correctly.
Carefully follow all prestart, startup, and operating procedures.

⚠️ Warning: Never bypass safety features such as the emergency stop switch. Eliminating safety features can result in personal injury to the operator and financial liability to the company.

Shutting off the water jet may not remove all pressure. Opening a fitting with residual pressure can produce a cutting, penetrating spray that can result in injury. To reduce high-pressure hazards, verify all pressure is relieved before disconnecting any ultra-high-pressure water line by bleeding off residual pressure and confirming all pressure gauges read zero before starting service. Ensure all connections are adequately tightened after performing service or maintenance.

Never modify your equipment without consulting the original equipment manufacturer (OEM). Modifications may void warranties, cause unpredictable equipment behavior, and result in personal injury or death, exposing the company to liability. If assistance is needed to diagnose an issue or resolve any uncertainty about performing a repair, contact the OEM service department before starting any service.

Safety is Not a One-Time Exercise

Adherence to safety protocols is essential for maintaining a safe working environment. If you do not have a copy of your water jet systems’ operating manual including outlining the safety protocol and operating procedures, please request one immediately from your OEM. If you’re using a Jet Edge system, please request one from our technical support page. For assistance with specific issues, contact our technical service team —they are always available to help.

Maintenance Support and Training

Jet Edge provides 24/7/365 live telephone support and is there for you if you need help and free factory training for those operating Jet Edge equipment. Additionally, a library of routine maintenance training videos is available so you can take advantage of real time training at your convenience.

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If you would like to learn more about Jet Edge Water jet Systems, visit us online at jetedgewaterjets.com. If you are ready to speak with your regional expert, just let us know on our contact us page, or call us toll-free at 1-800-JET-EDGE (538-3343), internationally at +1-763-497-8700.

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