Search Results for high-purity water

Materials of construction for equipment and piping in pharmaceutical processing plants must be resistant to corrosion from the high-purity water, the buffer solutions used in preparation of the products, and the cleaning solutions used to maintain the purity of the product. The primary water used in pharmaceutical production is water for injection (WFI). This article presents the steps for preparing WFI and discusses the effect of chlorides on stainless steel. It provides information on the passive layer of stainless steels and chromium-containing nickel alloys. The article provides information on the surface finish of pharmaceutical equipment. It discusses the classification of rouge and the characteristics of cast type 316L stainless steel. The article also explains how and when to perform cleaning and repassivation process on classes of rouge.

This article describes the four major conditions that can cause beryllium to corrode in air. These include beryllium carbide particles exposed at the surface; surface contaminated with halide, sulfate, or nitrate ions; surface contaminated with other electrolyte fluids; and atmosphere that contains halide, sulfate, or nitrate ions. The article provides information on the behavior of beryllium under the combined effects of high-purity water environment, stress and chemical environment, and high-temperature environment. The compositions of the structural grades for intentionally controlled elements and major impurities are tabulated. The article discusses the in-process problems and procedures that are common but avoidable when processing beryllium and aluminum-beryllium composites. It also describes the types of coatings used on beryllium and aluminum-beryllium. These include chemical conversion coatings, anodized coatings, plated coatings, organic coatings, and plasma-sprayed coatings.

This article is an atlas of fractographs that helps in understanding the causes and mechanisms of fracture of P/M aluminum alloys (aluminum-lithium alloys) and in identifying and interpreting the morphology of fracture surfaces. The fractographs illustrate the fracture surface, and corrosion-fatigue crack initiation and propagation of these alloys.

This article discusses the corrosion characteristics of superaustenitic stainless and duplex stainless steels, which are used in pharmaceutical industry. It describes passivation treatments and the electropolishing of stainless steels. The article informs that electropolishing is not a passivation treatment, although the proper execution of the process will result in a passive surface. The article concludes with a discussion on roughing, which is a phenomenon of particular interest to the pharmaceutical industry.

This article discusses the materials of construction found in pharmaceutical production facilities. The materials discussed are different stainless steels, nickel and nickel-base alloys, titanium, zirconium, impervious graphite, fluoropolymers, and glass-lined steel. The article describes the three primary causes of failure in the manufacture of pharmaceuticals: embedded iron, failures of glass linings, and corrosion under thermal insulation.

Tin is a soft, brilliant white, low-melting metal that is most widely known and characterized in the form of coating. This article discusses the primary and secondary production of tin and explains the uses of tin in coating, namely tinplating, electroplating, and hot dip coatings. It presents a short note on pure (unalloyed) tin and uses of tin in chemicals. The article also covers the compositions and uses of tin alloys which include solders, pewter, bearing alloys, alloys for organ pipes, and fusible alloys. It goes on to discuss the other alloys containing tin including battery grid alloys, type metals, copper alloys, dental alloys, cast irons, titanium alloys, and zirconium alloys. Finally, it presents a short note on the applications of tin powder and corrosion resistance of tin.

This article focuses on the corrosion fatigue testing of steel in high-temperature water and discusses critical experimental issues associated with it. It provides information on the fundamental aspects of environmental crack advancement in general. The article explains the concepts and role of environmentally assisted crack growth in corrosion fatigue. It also discusses the fatigue test methods, including crack initiation testing and crack propagation testing. The article describes the specific types and influence rankings of experimental variables in corrosion fatigue.

Chemical brightening (bright dipping) and electrolytic brightening (electropolishing) are essentially selective-dissolution processes, in which the high points of a rough surface of aluminum are attacked more rapidly than the depressions, and the peaks and valleys are smoothed to produce a bright and beautiful finish. This article discusses the metallurgical factors, optical factors, and applications of the chemical and electrolytic brightening. It compares the chemical brightening and electrolytic brightening, and presents the advantages of the chemical and electrolytic brightening processes in terms of performance and economy. The article describes the phosphoric-nitric acid baths and phosphoric-sulfuric acid baths used for chemical brightening. Solution compositions and operating conditions for three commercial electropolishing processes, as well as for suitable post-treatments, are presented in a table.

This article presents a detailed account of ion chromatography (IC). It begins by describing the principles of common separation modes in IC. This is followed by a section on the different modes of detection, namely suppressed conductivity detection, nonsuppressed conductivity detection, spectrophotometric detection, and electrochemical detection. Various separation modes in IC are then described. The article further provides information on various eluents species, analyte range, and sample preparation techniques in IC. It ends by providing information on the instrumentation and applications and future directions of IC.

This article briefly reviews the production methods and characteristics of plain carbon and low-alloy water-atomized iron and steel powders, high-porosity iron powder, carbonyl iron powder, and electrolytic iron powder. It emphasizes on atomized powders, because they are the most widely used materials for ferrous powder metallurgy. The article provides information on the properties and applications of these powders. It also includes an overview of diffusion alloying, basics of admixing, and bonded premixes.