Waterjet cutting costs

The operating costs of Waterjet cutters include:

  • Electricity
  • sand
  • operator
  • consumables for the pump
  • nozzles and mixing tubes in the head
  • water

Waterjet systems for water cutting use two types of high-pressure pumps: direct (crank) and indirect (with pressure booster). Pumps with a pressure intensifier were the first to be created .
In indirect pumps, oil with a pressure of 200 bar is forced to a piston pressure intensifier with a ratio of 1:20 and thus a pressure of 4,000 bar is obtained in the output stage (water).
In addition, pumps with an intensifier reach a power of 50KM (crankshaft 30KM), which significantly extends the range of orifices of various diameters, directly affecting the quality and efficiency of machining.
Pumps with an booster used in Kimla Water jets enable smooth and easy pressure adjustment from 500 bar, which automatically solves problems occurring in crank pumps.

In crank pumps, the water is pumped by three pistons driven by the crankshaft. The only positive feature of the crank pump is that it achieves greater efficiency (by approx. 10%) than in the case of classic pumps. This is due to the lack of an intermediate oil supply, which becomes hot during operation.
The pressure obtained in crank pumps is 3500 bar, and in modern pumps with an booster up to 6000 bar (during tests, pressures up to 14000 bar were obtained). In addition, crank pumps are up to four times more expensive to operate, because the frequency of piston movements is several dozen times greater, which leads to the need for frequent replacement of expensive consumables. Taking into account some electricity savings, the operating cost of a classic pump is still half that of a crank pump.
Another serious problem in using crank pumps is the inability to stop the pump immediately, leading to large energy and water losses.
Moreover, the limited possibility of regulating the pressure in crank pumps by regulating the engine speed with an inverter increases the operating costs. The minimum rotational speed of the engine ensuring its reasonable cooling gives too high pressure to safely pierce and cut glass, which results in the need to use additional heads limiting the energy of the water stream.