For the great majority of waterjet owners in the U.S. and Canada, the answer is “no”. More than 90% of the water than comes from a city’s water supply in these countries can be used in an abrasive waterjet without any treatment. For those areas that fall into the exception, waterjet owners can save significant time and money by conditioning the water, no matter what brand of waterjet machine they’re running.
Get a Water Quality Analysis Before You Buy
Waterjets use between one half and five gallons (2 to 19 liters) of water per minute when cutting. Some of that water is used to cut and some of it is used to cool the pump. Systems using intensifier pumps use much more water for cooling than do systems with direct drive pumps. Before purchasing a waterjet, get an analysis of the water that will be used in the waterjet system from a qualified testing company. The water should be tested for "total dissolved solids" (TDS), not just for bacteria. Dissolved minerals in the water can do a lot of damage to the high-pressure equipment. Even if the parts per million of dissolved solids in your water initially tested within the allowable limit (typically at or below 250 ppm), you should periodically retest. Water quality can change when there is unusual weather or your water department switches reservoirs. If you find that nozzles are wearing out quicker than normal, water quality could be the issue. In addition to testing for TDS, check the temperature of the inlet water and compare that to the waterjet manufacturer’s temperature recommendations.
Protect Your Investment
Based on the results of the analysis, if water treatment equipment is recommended by the waterjet manufacturer, you’ll likely reduce your operating costs a lot by investing in the treatment equipment, to the degree that you could yield a return on that investment in less than a year! The types of water treatment systems that may be recommended include a reverse osmosis system, water softener or a water chiller.
TDS reduction can be achieved through reverse osmosis or through deionization using a water softener. The OMAX Reverse Osmosis System fits between the incoming water supply and the waterjet pump. Pressure is applied to a saline solution and water flows through a semi-permeable membrane that rejects 80-90% of inorganic solids. In cases where the “hardness” of the water is high but the TDS is below 250 ppm, a water softener is typically recommended. Water softening is an ion exchange process that removes scale-forming minerals (calcium and magnesium).
If the water temperature gets above 70° F (20° C) the seals in the high-pressure pump can soften and extrude much sooner than if the water temperature is kept cooler. This typically leads to more frequent pump maintenance. If the water is being recycled through a recycling system, heat will accumulate in the water as it cycles through. Regularly check your water temperature and if recommended, use a chiller to keep the water at the optimum temperature.