Water Jet Cutting: The Importance of Water Quality

When it comes to water jet cutting, the quality of water used plays an important role. The very first hurdle in water quality is to filter out all impurities before it reaches the high-pressure line or cutting head. These impurities are measured in parts per million, or ppm, and consist of dissolved and suspended solids. There should be a total dissolved solids (TDS) in average tap water ranges from 140-400 ppm, with 500 ppm which is considered to be not safe for n consumption.

The water that is supplied to the intensifier pump can directly affect the service life of waterjet components. Having high concentration of TDS will cause the water to accelerate the wear of any components that come in contact with the water because of its increased abrasiveness.


Other Factors to Consider

Suspended Solids

In addition to the issue for total dissolved solids when talking about water jet cutting, water must be filtered for suspended solids. These are solids in the water that becomes trapped by a filter, whereas for dissolved solids, they would pass through a filter. Suspended solids constitute a variety of material, including decaying plant matter, silt, industrial wastes, etc.

In addition, suspended solids can also cause shortened pump life and difficulty with seals and nozzles. At the same time, if suspended solids get it into the high-pressure stream, they will act as an abrasive and damage the high-pressure equipment. Both the pre-filtration and final filters are designed for this purpose. This, however, depends on the size of the particle that should be removed. The filters are located inside the pump before the intensifier and this is easily changed by hand. All in all, the pump will send a notification when the clogged final filter should be replaced.


pH Level

The pH level of the water is just as important as the total dissolved solids as well as suspended solids. In case the inlet water has a low pH, the acidic properties can cause damage to the high-pressure tubing. This can lead for replacement more often than necessary. Also, if the inlet water has a high pH level, the basic properties may cause scaly buildup of calcium carbonate on the high-pressure tubing. This buildup of calcium carbonate will soon break off, move through the high-pressure tubing to gain momentum, and damage the orifice of the waterjet. Water used in a such cutting system needs to ideally have a pH level of 7 which is neither basic nor acidic. Adding water softener to regulate the pH level of the inlet water is a quick fix that is highly recommended by waterjet technicians.


Water Temperature

Water temperature also has a great effect on the life of the components. The water that enters through the high-pressure pumps should be kept cold (below 70* F), if not, it can affect seal longevity. Water coming from the tap may already be cool enough for some companies, if not, manufacturers would suggest a chiller system.

Other environmental factors such as rainfall and temperature of the climate may also affect the initial water temperature. If this is the case, waterjet professionals usually recommend a closed-loop system with chillers that will help keep everything at a constant temperature.

With the information given above, it’s important to know and make sure how important it is to secure the quality of water.