Paradoxically, you don’t want your water to be too clean, as water is an excellent solvent and if you remove all the trace materials from it, it will begin to dissolve your pump and nozzle parts.
Have your water quality tested while you are evaluating equipment to purchase. Some manufacturers will do this for you, and give you suggestions on any action you may need to take if your water requires it. In the worst case scenario, you will have to purchase some sort of water cleaning system such as a reverse osmosis filter, or water softener, or water chiller. Follow the manufacturer’s recommendation. If they say you need extra equipment, then believe them. They don’t want unnecessary technical support calls, and neither do you.
Also remember that just because you have your water quality tested once, does not mean your water quality will stay consistently good. When there is unusual weather, or for other reasons, your water department may switch reservoirs. If you suddenly find that you are wearing out nozzles faster than normal, suspect water quality to be the culprit.
Make sure your water quality is tested for “total dissolved solids” (or TDS), and not just bacteria. You won’t be drinking the water—you will be using it to make parts. It is the dissolved minerals in the water that will cause the most trouble. Other problem areas are solids in the water that may clog filters.
Water temperature has a big effect on seal life in high-pressure water pumps. Keep the water cold (below 70° F / 20° C). Otherwise, the seals may tend to soften, extrude much faster than normal, and result in dramatically more frequent maintenance of the pump. If you are recycling your water this is especially important, since heat will accumulate in the water as it cycles through the system. In some cases, a water chiller may be recommended. Talk to your manufacturer for recommendations.
An Ebco brand closed-loop filtration system
A closed-loop filtration system will recycle your water and filter it, both reducing your water consumption and keeping your water clean. If you are cutting a lot of toxic substances such as lead, something like this may be necessary. If you do use a closed-loop filtration system, you may need to add a chiller to keep your water temperature low to avoid excessive wear on your water pump.
Waterjets use between ½ and two gallons (2 to 8 liters) of water per minute when cutting. Some of the water is used for cutting, and some for cooling. The water is typically treated as “gray water” which can be recycled, or sent directly to the sewer. Again, if you are cutting something toxic, you may need to filter water, and recycle or dispose of it in special circumstances.
SUPER-WATER® is a chemical you can add to the water of an waterjet to focus the cutting stream, increase cutting speed, and reduce wear of high pressure components. Traditionally it has been used for high-pressure cleaning and water-only cutting applications. Although it is not widely used in the waterjet cutting industry, it may offer some benefits. More information on SUPER-WATER®.