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Steve Kentley's Waterjet Homepage
Specializing in Waterjet Technology Solutions in Southeast Asia
I am currently in New York City. I DO NOT have waterjet equipment for sale, nor do I provide contract cutting services. I regret that I cannot offer quotations for off-the-shelf equipment or cutting services at this time, but I may be able to connect you with someone in the region who can help.
I am available for freelance, temp, contract, part or full time work. If you are interested in my services as a waterjet consultant or for CAD or design work, or have a specialized system in mind, then let me know and pitch me your project and budget. If you want an off the shelf turn key system, then you are looking in the wrong place. See my design page for more info. If you have a waterjet question, send me an e-mail.
Cheers,
Steve
[ Introduction | Services | Mission | Applications | Applications List | Realities | Contact | Top ]
Introduction and Description
Waterjets have been around in industry for a few decades, but their use has not spread in Asia as rapidly as in other parts of the world. By providing information and expertise in this field to interested customers in Asia, I hope to spread the use of waterjet technology through the entire region. If you are interested in waterjets for your application, or are planning to invest in a system, or just want to learn more about them, please explore further or contact me at the e-mail address below.
I specialize in waterjet technology solutions. My preferred region of operations is in Southeast Asia, but I am available in New England in the USA. I have worked with waterjets for 13 of the last 17 years, with the other two years being spent doing micro-machining (cutting and welding) with Nd:YAG lasers. I have worked with 9 different waterjet systems and 5 different laser systems. I finished a three year stint as a research fellow in a manufacturing research institute in Singapore where I worked on custom WJ applications for a variety of industries including Marine, Aerospace, Electronics, Manufacturing, and Civil Defense. This included building custom machines, modifying existing machines and performing feasibility studies using waterjet technology. Have passport, will travel.
I have worked on thick section cutting of steel and titanium up to 10" thick with a very powerful jet, waterjet cutting and cleaning projects in the shipyards, 3D machining with a large 5-axis machine, fine beam cutting with jets under 0.5mm (0.020"), and on abrasive suspension jet systems (ASJ) with nozzle size down to 0.25mm (0.010"). I have worked with Flow systems, Ingersoll-Rand intensifier pumps (including the new Hard Seal End Cap topworks) and DIAJet systems.
The pictures at the top of the page are of a multi-nozzle cleaning arm for shipyard use and of a fine beam cutting sample of a Chinese character pendant in 3mm thick stainless steel. The pictures below are of a very low pressure abrasive suspension jet cutting 5mm thick steel and an abrasive entrainment waterjet system cutting 10" thick titanium.
If you are interested in my services or are looking for someone with extensive waterjet experience, send me an e-mail, stavros1000@pacific.net.sg
And remember "If you found me, then you need me."
[ Introduction | Services | Mission | Applications | Applications List | Realities | Contact | Top ]
Services
Consulting for:
Waterjet and Abrasive Waterjet cutting and cleaning
System selection and location suitability
Application feasibility
Custom applications: design, build and integrate
Custom tools and manipulators
System / Process improvements
Industries served:
Manufacturing - Precision machining, job shop work, profile & 3D cutting
Aerospace - Precision cutting, rough cutting, blanking, composites
Construction - Cutting, cleaning, coating removal and hydrodemolition
Marine - Cold cutting, cleaning, coating removal, sub-sea cutting
Military - UXO / EOD / Landmine remediation
Civil Defense - Fire, Safety & Rescue applications
Architectural - Signage, mosaics, glass, stone, ceramic cutting
[ Introduction | Services | Mission | Applications | Applications List | Realities | Contact | Top ]
My Mission
My Mission is to grow and expand waterjet technology in Southeast Asia and the Asia Pacific region by promoting waterjet technology and providing solutions to companies interested in exploring waterjets for their processing or production problems.
For this I focus on three areas:
1: Evaluation of existing needs and recommendations for using waterjet technology over traditional methods.
This service is for initial feasibility studies and technology familiarization so an organization can make the right decision on whether waterjets are the right solution for their technological need. Included in this area is the sourcing of third party waterjet services, either as a solution or as a trial for decision making or a follow-on system selection.
2. Waterjet system selection and implementation into a customer's facility, including site preparation before equipment is specified, and staff training after equipment installation.
Site preparation can have a large impact on the successful and profitable operation of waterjet equipment. In the same way, after the equipment is installed, the organization will often need to be taught how to maximize productivity with their new waterjet equipment.
Factory training with OEM equipment is always a good idea, but there are things that one learns over the years that will not be taught in a short training course for new operators. Often this information can shorten the learning curve for a new machine owner / operator, and lead to cost savings. It can also help a company optimize their process and waterjet equipment usage.
3. Custom tool, equipment and system design & development meant for unique and custom applications, or to replace an existing method or technology that is no longer suitable.
There may not be a way to handle a certain production or machining task currently. Maybe existing tools or equipment are not suitable or not adaptable to the application, or someone wants a better way to do something. Thus new and unique solutions need to be developed to get the job done. Also existing solutions may not be suitable for certain applications due to issues with materials, worker health, enviromental concerns, fire hazards, or access. Waterjet solutions can overcome many problems due to the inherent cold cutting nature of the abrasive waterjet, the environmentally friendly nature of processing with water, and the ability for waterjets to be customized to just about any application.
[ Introduction | Services | Mission | Applications | Applications List | Realities | Contact | Top ]
Applications
Waterjet Applications
Waterjets can be applied to almost any industry. There is usually something that a fluid jet can accomplish better, faster, safer, or cleaner than by some conventional method. Whether it is removing paint from a ship hull to replace abrasive grit blasting, or cutting frozen food products with a blade that never goes dull or cross-contaminates other products, profile cutting metal plates, or cutting circuit boards, waterjets can handle many different tasks.
Some examples of the wide variety of waterjet applications follow. They are grouped loosely by industry. These are just a few different applications. Difficult problems often spur a new waterjet solution. Contact me with your application.
[ Introduction | Services | Mission | Applications | Applications List | Realities | Contact | Top ] Manufacturing Applications for Waterjets
Waterjets excel at machining and manufacturing.
Any material can be cut in any shape that you can draw. The cutting is fast and safe for the material and the operator. The parts can be used "as is" from the jet, or minor secondary finishing can be done. Or the jet can cut parts to near net shape, taking advantage of nesting parts close together on the plate of material, and then final machining to tolerance can be done with conventional tooling for the desired accuracy and surface finish.
One industry that has taken advantage of waterjet cutting is the sign industry, where waterjets are used to cut plate and sheet metal in the shape of letters and logos for buildings. Any shape, any font, any material can be cut. Marble, stone and tile can all be cut without breakage, and intricate inlays of different color materials can be created, producing stunning results.
Waterjets can be used to cut through material, to mill features such as pockets in any material, including glass and ceramics. Waterjets can be used for turning of cylindrical features.
Brittle material such as glass, ceramics and even semiconductor silicon wafers can be safely pierced and cut with waterjets.
Manipulation can be done with single axis machines, XY cutting systems, 5-axis machines for complex 3D machining. Different configurations include lathes, hand-held routers, and bandsaw type machines. Cleaning Applications for Waterjets
Cleaning with waterjets is very effective.
Water is one of the best and most important chemicals we know of. It has very good cleaning capabilities on its own, but when it is pressurized and directed at a target is a controlled manner, it is extremely effective in many applications, even stripping the rubber residue from an airport runway. The water will penetrate the smallest pores and remove trapped contaminates. When set up properly, the waterjet will not harm the base material being cleaned. It is not like grit blasting which changes the surface structure. In fact while grit blasting rounds over and traps contaminates in the small pores and the anchor pattern of the material, a waterjet will not affect the surface roughness.
In addition, waterjet cleaning removes toxic and hazardous solvents from the cleaning process. It is safer and cleaner than chemical cleaning and stripping. Also, the process water can usually be collected, filtered and either treated for release to drain or recycled in the pump. The benefit is that the dirt and residue are collected in smaller amounts for easier disposal.
Cleaning systems can be as simple as a hand-held lance operated by a person, or they can be all the way up to multi-axis CNC machines for complex machine parts, and anything in between. Cleaning can even be done underwater. Pump pressure, system complexity and ultimately cost will all be determined by the application. Construction Applications for Waterjets
Waterjets can be use in the construction industry to cut, clean and perform hydrodemolition, which is the process of removing old, degraded concrete from a structure in preparation for repairs.
A high pressure waterjet can clean concrete for painting. It can remove concrete to whatever thickness is desired for new surfacing, structural repairs, access and conduit holes, bridge deck repair and recoating, etc.
Waterjetting is so good in concrete applications because the high pressure water forces itself into the smallest cracks and breaks out the already weak concrete, leaving the solid, uncracked material unaffected. The rebar is cleaned, but not cut or damaged from vibration. The noise is much less compared to pneumatic percussive drills. It is friendlier to the operator and the surroundings. There is no dust. Waterjetting is very flexible. It is fast and provides a clean anchor for new concrete. In short, there are many benefits over existing concrete refurbishment techniques that make waterjetting the preferred solution.
Abrasive cutting of concrete is also a very effective technique. The abrasive waterjet cuts cleanly though the concrete, aggregate, and rebar to produce a clean and relatively smooth cut in whatever thickness of concrete. Different shapes can be cut, and different manipulation techniques can be used to cut any shape in any location.
Waterjetting has a large potential to be very important to the construction industry. It is a very versatile tool that has many untapped applications. Marine and Offshore Applications for Waterjets
Waterjets can be used in several ways in Marine applications.
Cleaning can be done at low pressure. Paint stripping and barnacle removal can be done at high pressure. Complete surface preparation can see all contaminates removed from the steel. Waterjets have the advantage over grit blasting in that the water does not alter the surface condition of the metal. Grit blasting will round over peaks and trap contaminates, while waterjets will blast out even the most stubborn trapped particles of paint, grit, or chlorides without rounding over the sharp anchor pattern. The overall result is a cleaner surface, which means that the following paint system will adhere with a stronger bond.
In addition, waterjet cleaning and paint stripping is environmentally friendly. Water can be captured, filtered and recycled while debris and residue are collected for waste disposal. Waterjets will leave a clean, ready to paint surface, and in many instances the jetting can take place right next to other operations at the same time. Dirty and environmentally unfriendly grit blasting can be eliminated, to the benefit of workers and bottom line clean-up costs.
The work can be done with hand-held guns, cherry-picker mounted arms or robotic crawlers that can traverse any surface, horizontally or vertically. They can even be attached to ROVs for deep underwater applications.
Cold Cutting is another marine application. Abrasive waterjets are very effective at cutting steel plates. Linear manipulation or custom systems can be used for almost any cutting job, be it on the side of a hull, a large pipe section, a rusted bolt on a flange inside a tanker, even underwater.
And waterjets are safe to use in hazardous environments. They are cold-cutting, they do not cause heat or sparks. They can be used in vapor-filled environments or to cut where there is still residue.
Waterjets have proven to be very beneficial and cost effective tools for Marine applications.
Oil & Gas and Petrochemical Applications for Waterjets
Waterjetting is valuable to the Petrochemical industry. Cleaning and cutting can both be used in different applications. From cleaning pipes, tanks and heat exchanges, to cutting steel plates, pipes, bolts, flanges, concrete, or whatever, waterjetting can do so many different jobs that it is the "do-all" tool.
They can be used to help fabricate components in a shop or in the field, refurbish or perform routine maintenance on pipes, welded joints and paint coatings. Cutting and surface preparation, cleaning and repairs are all suitable for waterjetting.
Waterjets can even be used as catalysts in chemical reactions, speeding up the reaction time and efficiency by affecting the mixing of chemical compounds.
Technically the jet doesn't even have to be water. The food industry use vegetable oil jets to cut food products, as the oil does not degrade sugars like water does. In UXO / EOD applications, liquid ammonia jets can be used to cut and washout energetic materials from military ordnance. Fire, Safety and Rescue Applications for Waterjets
Waterjets can be used in several fire, safety and rescue applications. Abrasive jets can be used to cut through any material so concrete walls and steel doors can be cut. Access holes for feeding water hoses, for ventilation or for high pressure watermist injection can be done. Locks, handles and hinges can be cut when existing tools are unsuitable. Combination abrasive cutting and watermist spraying systems can be developed.
Abrasive jets can also be used to cut rubble and debris. The cold-cutting nature of the jet means that explosive hazards are reduced dramatically over tools that may cause sparking. Remote systems can be very useful in situations where operators could be in danger of a building collapse. Portable systems are available that allow two operators to hand carry the cutting equipment to a remote location. Military and Ordnance Remediation Applications for Waterjets
Waterjet cutting of munitions has been proven safe and effective.
It can be used in remote field cutting situations, such as landmine cutting or UXO cutting, or it can be used in a production setting for stockpile decommissioning. Waterjets can safely cut cases, propellants, and fuses. Waterjets can safely and effectively wash out the explosive charges and propellants inside of a shell for reuse, often with the same system that is used for cutting the shells to begin with. Waterjets have even been used to detect landmines, and to liquify and remove the soil around them, and then to cut the mines in place, all from a remote location.
Taking advantage of the cold-cutting nature of waterjets, UXO / EOD / Landmine remediation is an attractive use for waterjets. One benefit is that it can be used to render safe and munition right where it is found. Another benefit is that the explosive device does not fragment and cause more detection problems for deminers or UXO personnel who must treat every "hit" as a live device.
Manipulation of the jet can be done to any desired path. Control of the jet can be all remote, with cables and hoses from the pump system to the cutting head and manipulator located a safe distance away from the operator. Vision systems help the operator follow progress and keep everyone at a safe distance.
Waterjets will not replace the existing UXO / EOD / Landmine removal methods, but they are a tool that can and should be used in the right applications and situations where the other methods may not be feasible. Food Processing Applications for Fluid Jets
Waterjets and fluid jets can be used in food processing applications. A fluid jet is like a knife that never gets dull. It never cross-contaminates. It is a non-contact way of cutting. A jet of vegetable oil can be used to cut cakes without the problem of water degrading the sugars in the cake. Frozen chicken and fish products can be cut into portions. Cleaning can be done with high pressure waterjets. Food preparation equipment, particularly on a large scale can be cleaned. Furniture, Arts and Craft Applications for Waterjets
The ability of waterjets to cut any shape in any material means there are many applications for fine beam jets in the arts and crafts area. Precision machining can be done on jewelry. Glass and metal picture frames can be cut in intricate patterns. Stone can be cut and milled, on both small and large pieces, for decorations or statues. Large blocks can be cut to rough sizes.Intricate patterns can be cut in wood panels and blocks for woodworking or architectural details. Shells and other odd materials can be cut to support local handicraft industries. Furniture manufacturing is another area where waterjets can give you the edge. The first factory waterjet cutting machines were used decades ago for cutting chair shapes from thick paper tubes. Nowadays, designers and artists are taking advantage of the waterjet's instant prototyping capabilities to design furniture that utilizes different materials and manufacturing techniques than were previously used. Waste Remediation Applications for Waterjets
Waterjets and abrasive jets can be used in the recycling industry and for waste remediation. Storage tanks can be cut into for access or cleaning. Steel structures can be cut up for dismantling. Surfaces can be cleaned of chemical residue, for instance cleaning up a road surface of oil or chemicals after a vehicle accident, or removing the epoxy layer inside a storage tank.
Realities
Okay, now for some realities about abrasive waterjetting that you should be aware of before you get into it.
Dust from the cutting process gets everywhere. It usually starts as mist from the waterjet piercing material or hitting a support structure and spraying upwards instead of into the tank. You can also get a lot of mist if you are cutting something weird, like cutting slots in a pipe. It you have sensitive equipment or need to maintain a clean environment, then you will have to take steps to deal with this dust. Companies do it all the time, so it is possible to run a clean operation if proper steps are taken. But remember there is no getting away from it totally.
Noise comes from the pump and motor, which can be loud. Noise also comes from the waterjet itself, particularly at pierce. Ear plugs are recommended. Submerged cutting can also reduce noise, but there is no getting around the fact that it can be loud. Think long term and wear ear plugs. Trust me.
Accuracy is an issue. Waterjets are not as accurate as lasers or EDM machines. The stream is much wider than a wire EDM or a laser beam. Plus the nozzles wear over time, so the stream gets wider and wider. It's about an increase of maybe 0.020" over the life of the nozzle if you push it. The cutting process itself leads to pressure fluctuations that cause edge striations. There may be edge taper and lead-in, lead-out marks also. Can you live with these? Will you do secondary finishing?
Fixturing has never been a big issue with waterjet cutting tables. You basically put up a flat plate, and cut the parts from that. Hold the plate down with some heavy weights to keep it from moving and dampen vibrations. It is when you start doing strange things like cutting pipes, large bent sheet metal panels, I-beams and channels, or pre-cut blanks that you have to become creative with fixturing. This is particularly true if you are seeking very accurate cuts. You usually have to innovate your own fixtures and holding methods for your particular application.
Abrasive goes into the tank, and abrasive must come out of the tank again. Over time the catcher tank fills with spent abrasive sludge. Unless you are using a self-cleaning tank, or an abrasive recovery system, you will have to take the machine off-line for a few hours for cleaning. Remove the support bars and either scoop out the sludge or have a vacuum truck come and suck it all out. Shoveling sludge out by hand is incredibly arduous, back-breaking labour. Remember it is heavy like wet sand.
Hazardous waste is present in waste water and waste abrasive in the form of heavy metal particles. Depending on what you are cutting, drain water and abrasive sludge may contain detectable and measureable amounts of copper, zinc and ??? This discharge may be regulated in some localities. You will have to research disposal methods for your application. You may even have to filter your drain water and get permits to dump the abrasive sludge.
Maintenance of the pump system is the biggest issue here. Seals wear out over time and with use. You have to keep stock of spare seals and parts to keep running when things break down. You'll need water filters and cutting nozzles. Occassionaly high pressure lines fatigue and leak and have to be replaced. On the cutting table, the support slats get cut up and become useless for maintaining a flat surface to rest material on, or to support heavy loads. They are replaced periodically. When it comes to maintenance and operation, don't put any availible body to run the machine. Use dedicated operators who will become tuned to the sounds and behaviours of the machine. And have the proper tools at the machine at all times. It will save you money to cultivate quality operators / mechanics, and to have the tools at the ready. Or you can just call the service guy to fly in, if he is availible, and there aren't 3 other serious downtime problems he has to fix elsewhere before coming to you. Your call.
Safety is always an issue with industrial machines, but waterjets are very safe. Accident rates are low. Most accidents involve people crushing fingers by moving material around. The high pressure equipment is very safe and reliable. The waterjet stream should be treated with a healthy dose of respect, as it can do considerable damage. As long as the operators are trained to understand the machine, the waterjet and have good work habits, you should have no more concerns about waterjets than you do about belt sanders and milling machines. Wear safety glasses, use hearing protection, and train the operators well.
Okay, having said all that, remember that waterjets can do some incredible things. They can do things that no other technology can do. I hope that by briefly explaining some of the drawbacks of this technology, it will help you understand waterjetting better. Don't always believe the sales hype. Remember to base yourself in reality first. This equipment is not cheap. I would hate for someone to be be disappointed in the equipment and technology because they didn't understand one of the drawbacks before they bought their machine.
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Images
Images
Waterjet components rendered in Autodesk Inventor software. I am current to Autodesk Inventor Suite 2009.
Contact Me
Contact Steven for a discussion of your interest in waterjets.
Mr. Steven KENTLEY
Tel: +1(646) 338-4281 (USA / NYC)
E-mail: (preferred) stavros1000@pacific.net.sg
URL: http://home.pacific.net.sg/~stavros1000/index.html
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This page last updated on 05 Jan 2011.
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