Vapor-degreasing,Stop Destructing the Ozone Layer!SOLUTIONS with Effective, Practical Advice
Its cleaning action occurred on the cold parts by condensation of the vapors of organic chlorinated solvents, dripping back to the tank with the contaminants like oil, grease and wax dissolved in the condensed solvent. Many good qualities of these solvents called collectively Chlorofluorocarbons (CFCs) (non-toxic, non-flammable, and non-reactive) contributed to their enormous diffusion, not only as degreasers but also as dry cleaners, aerosol propellants for many liquid applications and as refrigerating vapors. Huge quantities of these substances released by human activities found their way to the upper layers of the atmosphere where they remain for very long times. However well informed and expert you may be, you could certainly benefit from a vast repository of online authoritative welding information. Important AnnouncementWhen you need Welding-metallurgy knowledge (Sponsored Links) In 1973 it was determined that, unfortunately, chlorine is a catalytic agent active in ozone destruction. Stratospheric Ozone is a critical barrier to the harmful effects of ultraviolet radiation from the sun, a proven cause of increased occurrence of skin cancer in humans, and of disruption of genetic processes in the life and development of many organisms. The Montreal Protocol was a negotiated international process to control and reduce the release of harmful substances depleting ozone through a set of agreed upon goals and milestones, designed to be implemented by the adhering members. Replacement compounds for the banned Vapor-degreasing materials previously used were actively researched, and then patented and commercialized. Unfortunately some of these compounds, while effectively dealing with the ozone depletion problem, are still contributing unacceptably to the global warming. In particular Hydrochlorofluorocarbons (HCFCs), intended as transitional CFCs replacements, although having low Ozone Depleting Potential (ODP), in comparison to CFCs, have still unwanted remarkable greenhouse effects. Therefore they too are scheduled for phasing out. The traditional equipment, now called Open Top Vapor-degreaser (OTVD), produced very high levels of atmosphere pollution. This type is no longer legal for operation in many European countries. Solutions for a regulated use of Vapor-degreasing, an ubiquitous manufacturing process, were introduced in the US to protect investments and to permit a time limited phasing out of older installations. Regulations call for a much tighter process control to minimize the possibility of the solvent reaching the atmosphere. The way these requirements are implemented are clearly spelled out in informative documents readily available to all involved. To ease on operators, acceptable alternatives of compliance are proposed, to be selected according to the convenience for the application covered. A Guide issued by EPA to the new requirements can be found in: See also: Newer Vapor-degreasing technologies which unfortunately are more expensive to realize, achieve the lowest levels of contamination by complete insulation of the processing materials from the atmosphere through a closed loop of circulation within air tight systems. It is reported that in closed loop systems air emissions are reduced 98 percent or more when compared with OTVD. Other types of newer equipment include airless and vacuum systems, each with its specific set of advantages and disadvantages when employed for applications of any kind. A short overview of these various versions can be found in: It is hoped that the collective efforts will show, in time, drastic reduction of hazardous ozone depleting activity caused by chlorinated hydrocarbons, by the implementation of the adopted resolutions. Meanwhile technological progress will find more suitable means for performing satisfactory Vapor-degreasing without affecting negatively the environment we depend upon. A new website page on Solvent Cleaning was recently announced (8) in Issue 94 of Practical Welding Letter for June 2011. Click on the above link to reach that page or on PWL#094 to read the newsletter. Any questions or comments or feedback? Write them down and send them to us by e-mail. Click on the Contact Us button in the NavBar at top left of every page.
To reach a Guide to the collection of the most important Articles from Past Issues of Practical Welding Letter, click on Welding Topics. Hardfacing
 BUILT BY:
Click on this Logo NOW! Follow SiteSell and you will be amazed... SiteSell Facebook SiteSell Twitter On SiteSell Twitter, visitors will learn who SiteSell is, through each person delivering personal insights into SiteSell... his news, his interests and perspectives. They can interact with each "SiteSeller" too, asking questions of programmers, coaches or anyone else. SiteSell YouTube SiteSell Blog Copyright (©) 2011, by Elia E. Levi and |
