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Service Center Banks on Large-Format Waterjet Cutting Machines

By: Brad Kuvin

Monday, December 1, 2014
 

Jacquet’s five U.S. service-center locations operate a total of 11 large-format Jet Edge twin-head waterjet-cutting machines. Table size typically measures 13 by 21 ft., and the machines feature 100-hp intensifier pumps.
The business objective of Jacquet Metals, a global supplier of stainless-steel and nickel-alloy sheet, plate, pipe and other products, is not to simply provide raw material to customers as commodities. Value added is the emphasis, and holding to that objective is exemplified by this fact: More than 90 percent of the product that leaves its facilities is cut parts. And while its five U.S. locations (the company has 23 locations worldwide in 18 countries) still operate seven plasma-arc cutting machines, much of the precision cutting being performed at U.S. Jacquet service centers falls on the shoulders of its 11 waterjet-cutting machines.

“And we’ll be adding additional waterjet machines in 2015,” adds U.S.-based CEO Terry Engle.

Jacquet locations carry more than nine grades of nickel-alloy plate (0.125 to 2 in. thick) and bar (0.5 to 3 in.), as well as 11 grades of stainless-steel plate to 6 in. thick. Home to its U.S. locations: Pottstown, PA (U.S. headquarters), Racine, WI, Houston, TX, Pineville, NC, and Carson, CA. Included among its diverse customer base are fabricators serving the oil and gas, power and pulp and paper industries.

Speaking to MetalForming from his office in Pottstown, Engle recites the company’s challenge (and opportunity): To continue to meet the requirements of its customers for tighter-tolerance parts, as lead times continue to dwindle. And that’s where state-of-the-art waterjet-cutting technology enters the picture.

Cut-Edge Quality in Demand

Jacquet locations carry more than nine grades of nickel-alloy plate (0.125 to 2 in. thick) and bar (0.5 to 3 in.), as well as several grades of stainless-steel plate to 6 in. thick. Shown are two examples of waterjet-cut parts: ½-in.-thick stainless-steel tubesheet (right), and cutting of a 6-in.-thick Type 316 stainless-steel valve body.
“We definitely have identified and adjusted to a trend toward waterjet and away from plasma, mostly to avoid the heat-affected zone from plasma,” Engle shares. “With waterjet-cut parts, our customers avoid the need to perform secondary machining operations or other edge-finishing processes such as grinding. Waterjet-cut parts can head straight to welding or other operations.”

Jacquet’s waterjet-cutting machines of choice are large-format (13 by 21 ft.) mid-rail-gantry setups from Jet Edge, Inc., St. Michael, MN. Of Jacquet’s 11 machines in use in the United States, six comprise the mid-rail design, which Jet Edge introduced in 2008. Its other, older machines are low-rail models, no longer manufactured.

“The mid-rail machines (precision ballscrews, Rexroth drives and motors and Servos digital communication) are incredibly accurate,” Engle notes, “with repeatability to ±0.001 in. And we work with Jet Edge engineers to ensure that the machines meet our strict requirements for providing tightly toleranced parts along with reliable on-time delivery meeting ever-shrinking lead times.

“We’ve seen lead times reduced by 50 percent in the last few years,” Engle continues, “from 10 days down to just five days, and we expect them to shrink to three days very soon. So, our focus with these new machines not only is on speed and accuracy, but on uptime. We cannot afford the machines to be down for unplanned maintenance. That means jet Edge must focus development, design and manufacturing on ensuring its machines are rigid, robust and reliable.”

The firm often runs its cutting machines 24/7, further emphasizing the need to maximize overall equipment effectiveness (OEE), a measure tracked closely at Jacquet. Aiding in that mission is a proactive and thorough preventive-maintenance plan (see sidebar).

Dual Heads, Plus Beveling

Further enhancing service-center throughput: all 11 of Jacquet’s waterjet-cutting machines are dual -head models, and are run off of 100-hp intensifier pumps. Standoff between the heads is adjustable either automatically (through the cutting program) or manually.

10 Tips for Maximizing Waterjet Uptime

…provided by Jet Edge, Inc., St. Michael, MN; www.jetedge.com.

Successful waterjet operations like those at Jacquet rely on the performance of proper routine maintenance on the machines. With waterjet operating pressures often exceeding 75,000 psi (5200 bar), proper maintenance will help ensure maximum uptime, productivity and profitability. It can mean the difference between winning and losing customers, and retaining existing customers.

Neglecting a waterjet system can result in costly downtime, lost opportunities and expensive yet preventable repairs. At ultra-high pressure, small leaks left ignored can turn into big and costly problems. Hydraulic oil left unchanged can break down and gum up a pump’s directional control valve, causing the pump to stop working. Cooling systems that are allowed to clog with mineral deposits can cause a pump to shut down. And, improperly torqued high-pressure components can cause short seal life and premature component failure.

Fortunately, all of these problems can easily be avoided by following your waterjet-manufacturer’s maintenance guidelines and taking the time to properly maintain your equipment. Here are 10 tips for preventing many of the common problems associated with improper waterjet-cutting machine maintenance.

1) Read, understand and follow the procedures in the manufacturer’s maintenance manual and take advantage of manufacturer training programs. Jet Edge offers its customers free training for the life of its machines every other month at its Minnesota headquarters.

2) Keep the pump cool. Hydraulic intensifier pumps use a heat exchanger to cool the pump’s hydraulic fluid; direct-drive pumps use water to cool the interface plate between the plunger pump and the high-pressure assembly. Cooling can be accomplished with a closed-loop chiller or with tap water—tap-water temperature should not exceed 70 F. If your water contains heavy mineral deposits, filter and soften it to minimize the deposits within the intensifier pump’s heat exchanger, and periodically clean the heat exchanger following the instructions in your maintenance manual. If excess scale develops within the heat exchanger, it will not efficiently cool the pump’s hydraulic fluid and the pump will shut down.

3) Use clean and cool water. Jet Edge recommends that cooling water and incoming process water be no warmer than 70 F and that it be pretreated to <100 TDS, PH 6-8, Silica <15 PPM. Replace pump water filters after every 250 hr. of operation, or possibly more frequently depending on local water conditions.

4) Hydraulic fluid must be clean. Follow the manufacturer’s guidelines for replacing hydraulic fluid and hydraulic and breather cap filters. When changing the fluid, take care to not contaminate the new fluid by keeping the working area around the system dry and free of dust, dirt and debris.

5) Closely follow the manufacturer’s pump startup and shutdown guidelines. Bring the pressure up slowly when powering on the system and bring the pressure down slowly when shutting down the system.

6) Properly maintain high-pressure components and seals. Replace leaking seals and tighten high-pressure leaks as soon as they occur. Even a small leak, if neglected, can cut a groove into an expensive high-pressure component, forcing you to spend time lapping the component or replacing it. Use two wrenches to tighten high-pressure fittings. When replacing intensifier seals, follow the manufacturer’s torqueing guidelines; improper torqueing often is the cause of premature pump-component failure and short seal life. Inspect and service high-pressure tube poppets when necessary, and follow maintenance guidelines for servicing the on/off valve and rod seal.

7) Keep the pump and motion system clean and well lubricated.

8) To maintain a consistent level of quality, have the motion system recalibrated periodically by an experienced technician.

9) Use quality orifices and monitor the orifice, nozzle and mixing chamber to ensure optimal cutting performance. An abrupt pressure loss often can be attributed to a damaged or blown-out orifice.

10) Use quality, clean and dry garnet and ensure that debris does not fall into the abrasive hopper when filling it. Supply dry air to the abrasive hopper.

Adding the second cutting head increases machine purchase price by just 20 percent or so, making the decision to effectively double output easy to justify, says Engle. “The twin-head design is a must as we strive to increase our speed to market and reduce turnaround time.

“Also, we experience no decrease in traversing or cutting speed with the second head,” Engle adds, “while holding our tight cutting tolerances.”

Jacquet offers customers a choice of three levels of cut quality, with finer cuts or those with tight edge-squareness tolerances and that run at slower speeds priced at the high end. Less-critically toleranced parts that can be cut at higher speeds are priced slightly less.

“The trend,” says Engle, “is toward the high end. And that includes the ability to provide beveled cut edges to facilitate welding of cut parts without the need to run the cut edges through a secondary process to add the bevel.”

Three of the firm’s 11 machines have been custom-engineered by Jet Edge to allow them to provide beveled cut edges—machines in Racine, Pottstown and Houston. Applications for this capability include cutting large plates that are then rolled and welded to manufacture tanks and vessels for the oil and gas industry, among other end-use applications. MF

 

See also: Jet Edge Waterjet Systems

Related Enterprise Zones: Fabrication


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