Tag: water quality

Quality of Water in Water Jet Cleaning-

This is a summary brief on the quality of water used in waterblasters, hydroblasters, and UHP WJ. Follow the equipment manufacturers detailed specification.

This is a brief of Water Quality which is used in pressure washers, water blasters, and UHP Water Jetting equipment. I compiled information from equipment manufacturers directly or from their published data.

When removing corrosion or coatings from projects, the contractor should use the best quality of water which is available within the constraints of the project. The better quality of water, the longer the the pumps will perform. For a paint or coatings re-application, the revealed substrate is often tested for residual contaminants- such as residual oil (water-break or fluorescent), or electrolytes (salts). The measurement on the surface should be below the limits of the project contractual requirements. In my opinion, the contractor truly does not want to add contaminants to the substrate.

Should you heat the water? That depends. Generally hot water will dissolve more “salts” than cold water. However, during the pump cycle the water is compressed and thus heated. You don’t want to use water that is so hot that bubble will form. So just be careful. Equipment manufacturers might place a limit on the upper temperature of the input water.

For specific details-see the paper Quality of Water in the library.

Quality-of-Water-2021-11-11

Quality of Water for Use in High Pressure Pumps

For 30 years, I have received questions about the quality of water that should be used for removal of coatings. How much dissolved material or minerals gets left on the surface? Just recently after an hour long webinar to 200 people, the questions was “What shoul the quality of the water be?”

Among the first comments which I received on the WJ standards documents came from Singapore: The complaint was that we didn’t advocate cleaning with brackish or filtered seawater.” Just recently in 2015, a Sherwin Williams representative talked about the methodology in Brazil where WJ was being used for primary surface preparation, and not just potable water. However, I also received call in the mid 190’s where contractors said that they could tell the difference of quality of water between municipality sources. The better the quality of water, the better the removal, and the less flash rust.

As a task group leader for NACE and SSPC, the task groups finally defined surface preparation water. Surface Preparation water is water of sufficient purity and quality that it does not prevent the surface being cleaned from achieving the WJ-1 degree of surface cleanliness or nonvisible contaminant criteria when contained in the procurement documents. SP water should not contain sediments or other impurities that are destructive to the proper functioning of the cleaning equipment.

The following is a monograph on

The Quality of Water to be used in Surface Preparation and to Protect the Pumps.

Quality of Water 2015-12-14