By Diane M. Calabrese / Published April 2023
Plunk a large rock into a full gallon bucket of water. Water will overflow thanks to displacement. Think of the rock as a crude pump. For at least five millennia pumps have been part of life. See the shadoof (also shaduf).
Countervailing forces and direct application of force have long been used to move water by giving it a push, a lift, or a pull. Clever minds long ago could see the utility of levers, pivots, and plungers.
High-pressure pumps that support evermore varied waterjetting applications are part of the legacy of clever minds. In this century, precision engineering has taken pumps and the waterjetting tools they make possible to a fascinating and—in some instances—almost fantastic level.
There are three easy ways to get an appreciation of technology and advancement in waterjetting. One is to look at the last 40 years—the choice of four decades inspired by this being the 40-year anniversary of the WJTA [Water Jet Technology Association].
A second way is to review the projects highlighted at the websites of companies in the waterjetting sector. And a third way is to turn to OTSI.gov (OTSI is the Office of Scientific and Technical Information at the U.S. Department of Energy.).
The WJTA is headquartered in St. Louis, MO. Read about its history via www.wjta.org/wjta/History.asp. The history includes an overview of the usefulness of waterjet technology in solid fragmentation (e.g., mining and hydrodemolition), coatings removal (e.g., cleaning and surface preparation), and cutting.
In the same year the WJTA formed, the second U.S. Water Jet Conference was held at the University of Missouri-Rolla. Proceedings from that conference have been converted to pdf (a freely available 494-page document), as have proceedings from other conferences, including the first U.S. conference (Colorado 1981).
“The Proceedings of the Second U.S. Water Jet Conference” (https://www.wjta.org/images/wjta/Proceedings/Binder2.pdf) provide serious grounding in the vision and diligence (equations and all) of those looking to amplify the natural force of water. From the protective garb to the endeavors highlighted—example, cleaning coke oven doors—a reader comes away with an incredibly optimistic view of the spirit and commitment of engineers and researchers aiming to do great things by pursuing faster, simpler, stronger methods that benefit all industries.
As the conference proceedings demonstrate, ideas and concepts came from many directions well before 40 years ago. One of the biggest companies in the waterjetting industry today is Hammelmann®, which was started in 1949 in Oelde in the state of North Rhine-Westphalia of Germany with a focus on making high-pressure pumps.
Today, the worldwide company makes not only pumps, but also tools for waterjetting applications. Its website showcases examples of waterjetting tools being used across industries, as well as a short, illustrated history of the pump innovations that it achieved. (See hammelmann.com/us/company/history.php.)
Each person anchored in the waterjetting industry has his or her own perspective on what represents a
significant advancement. The waterjetting sector provides tools that do more with less energy and less water. It is quite a valuable companion in the ongoing quest for sustainability.
Stephen LaViers, who is in regional sales and rentals at Hammelmann Corp. and based in LaPorte, TX, cites an example, “Implementation of water recycling in the hydrodemolition sector has allowed the reduction in water consumption for projects on the order of 50 percent resulting in substantial improvement in the environment.”
Hydrodemolition tools are important to contractors in our industry who themselves meet ever more stringent regulations for containing and handling wastewater and waste. Waste reduction alone is a significant advancement.
Of course, waterjetting tools do much more than boost efforts at conservation in our environment. They also enable conservation of tissue during surgeries. Removing neoplasms while minimizing damage to surrounding tissue is a surgeon’s goal. Thanks to computer-assisted, remote imagery, some tumor extraction can be done with waterjets instead of blades. This means less tissue damage and less blood, and faster procedures explain the many types of surgery for which waterjet is being trialed.
Trials of waterjet-assisted surgery have shown great promise in a therapeutic approach for advanced colorectal cancer. It’s a surgery in which conserving tissue (perhaps for use in reconnecting parts of the colon or for use in a new connection to a colostomy) and speed both improve outcomes for the patient.
Use of jetting tools in surgery does bring some risks. One is that water can accumulate in sufficient amounts to distort the view of the site. Another is the mingling of water and pathogens and tissue debris that could become airborne (and disperse). Even so, it’s an active area of trials and comparisons with other tools, including laser.
Prior to the development of precision engineering, achieving exacting tolerances—matches in parts that come into contact with each other—was a lot more difficult and before that impossible. Waterjet cutting can reduce variance in dimensions of parts to the de minimis range.
The performance of cutters relies on dependable pumps, and technology assists in assuring that dependability. For example, Jet Edge Waterjet Systems in Saint Michael, MN, offers its Hero 50 waterjet intensifier pump with Jet Smart controls. The controls allow the pump performance to be monitored in real time with an interactive control pad.
An excellent list of questions and answers about waterjetting comes from NLB Corporation (Wixom, MI). See www.nlbcorp.com/resources/faqs.
Improved performance of equipment and sustained good outcomes from the equipment are objectives waterjetting applications typically meet. Any corrosion or oil or dirt on a wind turbine blade can disrupt its optimal function. Pipes in any sector become less efficient (and reliable) when they are coated with contaminants. Cleaning with waterjetting tools assists in both settings.
Gregg Day and Todd Rutenbeck writing in 1999 from the Technical Service Center at the Bureau of Reclamation evaluated potential of waterjetting for cleaning concrete dam foundation drains. (See their paper at www.usbr.gov/ssle/damsafety/TechDev/DSOTechDev/DSO-98-16.pdf.)
Day and Rutenbeck run through a chronology of improvements that occurred from the 1960s to 1999 in waterjetting alongside higher pressures. They cite remotely operated equipment, hole boring, rotating heads, wastewater collection, and increased rates of removal (whatever is being removed). The end result is lower costs. Pump pressures serving waterjets were already as high as 60,000 psi in 1999.
Fast, versatile, autonomous, re-source conserving and waste reducing are the general features that apply to waterjetting tools today. All in addition to “tough.”
The riches in research involving waterjets archived by OSTI just since the beginning of 2022 will definitely add to optimism about the world. Industrial problems of all sorts are finding solutions involving waterjetting, and the research extends far beyond industry.
We mentioned medical applications. Archeologists are also exploring the possibility of extracting core samples to hunt for evidence (e.g., pollen, spores) of human communities that have since been submerged because of tectonic movements and changes in sea level.
Many archived OTSI reports are about comparative research: Which method is better? That’s the question researchers aim to answer, and, in most cases, the studies result in an “it depends” on other variables (microenvironment) and goal (e.g., less environmental impact, interval to next application).
Surface preparation before applying a coating can improve longevity of the coating and the substrate it protects or, if faulty, reduce the integrity of coating and the substrate. Many studies look at the effects of dry abrasive blasting and waterjetting to prepare offshore structures (including wind turbines) for a coating that controls corrosion.
There’s a great deal of interest in using micro-abrasive waterjet (micro-AWJ) trepanning (burr holing) in the aerospace, automobile, and defense industries. Getting to a consistency in the dimension of holes that makes rejection of parts exceedingly rare is the goal.
If there are issues with one method, can it be paired with another for better results? Perhaps water droplet machining (WDM), pure waterjet cutting, can be used with AWJ to get desired results in cutting carbon fiber reinforced polymer.
Waterjet cutting alone, without an abrasive, is generally restricted to softer material. Abrasives provide the partner required for cutting metals.
The R&D is certain to bring more outcomes that meet the needs of end users. Some of the innovations will even be paired with extras.
In January 2022 Flow International Corporation in Kent, WA, announced the MotoJet X, a “next-generation” technology intensifier pump. It has a 95 percent uptime guarantee and “white-glove” full service with the company’s technical service team doing all routine maintenance.
In March 2022 OMAX Corporation (a Hypertherm company) in Kent, WA, unveiled its OptiMAX system, which reduces the need for highly experienced operators because it turns prints into parts using intuitive software. The software enables optimization in cutting and works in tandem with enhanced automation.
Whether a water cannon developed in Russia to fracture rock is the oldest point (1937) on the waterjet lineage is a debate best left for time to tell. One thing is certain, though. Most of us cannot begin to imagine what the farthest endpoint of conjunction of water and pressure will be—or where it will be.