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Glossary
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The Glossary: The following terms are most often used (or misused) in discussions in standards committee meetings. We will continue to add to this Glossary as time and suggestions allow.
Dr. Frenzel's definition of SURFACE PREPARATION: Creating the situation so that the coatings will perform as expected.
Flash rust, is an oxidation of the steel that occurs, within minutes, as the water is drying. Flash rust is also the rusting of steel as a water-borne coating is drying. Steel naturally oxidizes when water is present. Flash rust quickly changes appearance to a rust bloom or water bloom over a large surface area. The color of the flash rust may vary depending on the age and composition of the steel and the time of wetness of the substrate prior to drying. Drying with hot air blowers or the use of the vacuum systems can reduce or eliminate the flash rust. Low-Pressure Water Cleaning (LP WC): Water cleaning performed at pressures less than 34 MPa (5,000 psig). This is also called "power washing" or "pressure washing." High-Pressure Water Cleaning (HP WC): Water cleaning performed at pressures from 34 to 70 MPa (5,000 to 10,000 psig). High-Pressure Waterjetting (HP WJ): Waterjetting performed at pressures from 70 to 210 MPa (10,000 to 30,000 psig). Nonvisible Contamination (NV): Nonvisible contamination is the presence of organic and/or soluble ionic materials such as chlorides, ferrous salts, and sulfates that remain on the substrate after cleaning Standard Jetting Water: Water of sufficient purity and quality that it does not impose additional contaminants on the surface being cleaned and does not contain sediments or other impurities that are destructive to the proper functioning of waterjetting equipment. Surface Preparation: Creating the situation so the coatings will perform as expected. This includes for example, consideration of: profile, visible cleanliness, non-visible contaminants, sharp edges, welds, voids, oil and grease, and humidity. Waterjetting (WJ): Use of standard jetting water discharged from a nozzle at pressures of 70 MPa [10,000 psig]) or greater. Waterjetting uses a pressurized stream of water with a velocity that is greater than 340 m/s (1,100 ft/s) when exiting the orifice. Water Cleaning (WC): Use of pressurized water discharged from a nozzle to remove unwanted matter from a surface. Wet Abrasive Blast cleaning (WAB) encompasses several different methods in which water, air, and abrasives are used to clean the substrate. The processes range from injecting water into abrasive streams propelled by air (air/water/abrasive blast cleaning) to adding abrasive into pressurized water stream (water/abrasive blast cleaning). Wet abrasive blasting has been found to be an increasingly popular application where dust cannot be tolerated in new and maintenance projects. The abrasive creates the profile. There are a large variety of systems for WAB ranging from almost all abrasive with a little water to mostly water with a little abrasive. Generic terms to describe specific air/water/abrasive blast cleaning methods are water shroud or wet-head blasting, wet blasting, low volume water abrasive blasting, and slurry blasting. Generic terms to describe specific water/abrasive blast cleaning methods are slurry blasting, abrasive waterjetting (AWJ), or abrasive injected waterjetting/blasting (AIWJ or AIWB). Ultrahigh-Pressure Waterjetting (UHP WJ): Waterjetting performed at pressures above 210 MPa (30,000 psig). Reference Sources for Glossaries: NACE/SSPC Standard nace no. 5/SSPC-sp 12 "Surface Preparation and Cleaning of Metals by Waterjetting Prior to Recoating" WJTA: "Recommended Practices for the Use of Manually Operated High-Pressure Waterjetting Equipment." |