Erosion applications

CVD/PVD thin films are usually considered as coatings having a thickness of less than ten microns. This is an arbitrary limitation and perhaps a better definition would be a coating that adds little if any mass to the substrate. Most thin films, in fact, are much less than 10 im and may be even less than 0.2 im in the newer semiconductor and optical designs, while some wear and erosion applications can be much thicker than 10 im. 

Hard coatings for cutting tools and erosion applications. 

The outstanding property of rubber in general is resilience, or low modulus of elasticity. The flexibility and physical properties of rubber account for its application in general engineering and automobile industries whereas its chemical, wear and abrasion resistance as a sacrificial material, plus its insulating properties are utilised in many corrosion and erosion applications in process industries. Rubber lined mild steel, pipes and tankages have been standard materials of construction for hydrochloric acid service for many years. 

S. J, Bull and A. Matthews, Diamond for Wear and Erosion Applications, Diamond and Related Materials, 1992, 1, 1049-1064. 

In agricultural ecosystems, the P cycle is more open than in undisturbed ecosystems, because some losses occur by the removal of agricultural products and in some situations by surface runoff and erosion. Applications of fertiliser are needed to compensate for these losses, as well as to raise the level of production above native levels. Where grazing animals are present, unevenly distributed returns of P through dung and, to a small extent, urine also occur. Consequently, in managed ecosystems the natural P cycle is modified by these additional factors, so that the importance of P mineralisation for plant nutrition is more difficult to assess. This is why... 

In low erosion applications, and in low pressure rating applications, cyclones are most commonly fabricated from sheet metal 10 or 12 gauge. Mild or galvanized steel is common for units smaller than about 1 meter in diameter. These units may have replaceable, flush mounted, metal wear plates affixed in areas that are prone to erosion. These areas normally include the inlet target zone and the lower cone section. 

Other examples of government and military applications of laser-based profilometry include the evaluation of rocket thruster nozzles to locate and measure flame erosion remote inspection of hypervelocity test track and the measurement of sludge deposits on tube internal surfaces. 

Pinch The industrial equivalent of controlling flow bv pinching a soda straw is the pinch valve, Mves of this tvpe use fabric-reinforced elastomer sleeves that completely isolate the process fluid from the metal parts in the valve. The valve is actuated bv applying air pressure directly to the outside of the sleeve, causing it to contract or pinch. Another method is to pinch the sleeve with a linear actuator with a specially attached foot. Pinch valves are used extensively for corrosive material service and erosive sliirrv senice. This type of valve is used in applications with pressure drops up to 10 bar (145 psi),... 

Interest in the application of turboexpanders turbine to FCC unit is very high, and deservedly so. The power recovery turboexpander offers practical improvement in FCC unit operating economics. Modern designs that encompass the entire system have fully overcome problems and concerns that may have existed decades ago. Expander metallurgy is available to vastly reduce erosion rates experienced when... 

A wide range of polyurethane-type products has become available in recent years for coating applications. These include simple solutions of linear polyurethanes, two-pot alkyd-isocyanate and polyether-isocyanate systems and a variety of prepolymer and adduct systems. The coatings can vary considerably in hardness and flexibility and find use mainly because of their toughness, abrasion resistance and flexibility. Uses include metal finishes in chemical plant, wood finishes for boats and sports equipment, finishes for rubber goods and rain-erosion-resistant coatings for aircraft. One type of coating is potentially competitive with PVC leathercloth. Both alkyd-di-isocyanate and adduct-diisocyanate compositions may be coated on to fabrics from solutions of controlled viscosity and solids content. Such coated fabrics are soft, flexible and, unlike PVC leathercloth, free from plasticisers. 

The information to be compiled about the chemicals, including process intermediates, needs to be comprehensive enough for an accurate assessment of the fire and explosion characteristics, reactivity hazards, the safety and health hazards to workers, and the corrosion and erosion effects on the process equipment and monitoring tools. Current material safety data sheet (MSDS) information can be used to help meet this requirement but must be supplemented with process chemistry information, including runaway reaction and over-pressure hazards, if applicable. 

As a slight departure from the present classification scheme, oxide-based cermets can be either oxide particles in a metal matrix or metal particles in an oxide matrix. Such cermets are used in tool making and high-temperature applications where erosion resistance is needed. 

For most process applications, the materia s of construction can be accommodated to fit both the corrosive-erosive and mechanical strength requirements. Manufacturers have established standard materials which will fit a large percentage of the applications, and often only a few parts need to be changed to adapt the valve to a corrosive service. Typical standard parts are (See Figures 7-3, 7-3A, and 7-4)... 

KCl-polymer (potassium chloride-polymer) muds can be classified as low solids-polymer muds or as inhibitive muds, due to their application to drilling in water-sensitive, sloughing shales. The use of polymers and the concentration of potassium chloride provide inhibition of shales and clays for maximum hole stability. The inverted flow properties (high yield point, low plastic viscosity) achieved with polymers and prehydrated bentonite provide good hole cleaning with minimum hole erosion. 

Refractory quality. Refractory lining was first developed mainly for use in the iron and steel industries. It was not until the refractory manufacturers began developing products specifically designed for FCC applications that tremendous improvements in erosion and insulating properties were realized. 

Lightarowicz, A., Cavilating Jet Apparatus for Cavitation Erosion Testing, Erosion Prevention and Useful Applications, ASTM STP 664, p. 530-549 (1979)... 

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