Waterjet surface preparation is typically performed using pressures from 20,000 to 40,000 psi, with rotating nozzle heads varying in diameter from 2 inches to 16 inches. Materials being removed include coatings, oxidation, or scales. The purpose of this research was to determine the effects of variables such as standoff distance, traverse speed, surface speed, rotation speed, and the head design.
Example of Bar Head tests
The relative effects of standoff distance, rotation speed, feed rate, and head design were measured and compared in these tests. Overall, the parameter having the greatest effect on performance was the feed rate, which also directly effects efficiency. The next strongest parameter was the head design; the bent arm head performance was 25 percent better than the bar head design, and jet angle improved performance by 15 percent. Jet path diameter appeared to reach an optimum around the 210 mm size range, although this was not a strong influence. Rotation speed effected performance in several ways, but was not shown to be very influential either. These tests showed that increasing rotation speed is not necessarily a direct path to allowing a faster feed rate; it should be kept within a range to produce a velocity between 10 and 25 m/sec (33 and 82 ft/sec) for optimum performance.
Examples of our UH-40 and UH-50 Rotating assemblies with Bar Head and Bent Arms options.
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