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Solvent Degreasing and Metal Cleaning
Solvent Degreasing and Metal Cleaning –
Future proof Vapour Degreasing from EnviroTech Europe
Innovation driven by legislation
Vapour degreasing, with or with-out ultrasonics, is the oldest, simplest and most effective solvent degreasing and metal cleaning process used today. It has, until recently, been subject to little change since it was first invented in the early part of the last century. In the UK, Europe, United States and other advanced industrialized economies increasingly stringent legislation to control emissions of VOCs, Global Warming Compounds, Ozone Depleting Compounds, and those compounds associated with human health concerns has led to new formulations for precision cleaning solvents.
Cleaning systems have had to change too. With increased legislation concerning the regulation of health and environmental safety, uses of solvents have been targeted and alternatives are encouraged by the relevant authorities and law makers, often without serious consideration of unintended consequences. For example, water-based cleaning is the obvious alternative but this has many disadvantages compared to vapour degreasing as although the machines are simple and relatively cheap the processes require multiple tanks for immersion or spray processing or long programmed cycles in batch machines for cleaning, rinsing and drying. Water based processes are slow, energy intensive and occupy more floor space than vapour degreasing equivalent where only one tank with small footprint is needed delivering shorter process times and most importantly using minimal energy. Then there is the disposal concern as the used water cannot just be disposed of by pouring it down a drain.
The ideal cleaning process would be vapour degreasing and cleaning with water, but due to the physical characteristics of the vapour/steam and the inability to carry surfactants to remove the oil, grease and soils and the difficulty of rinsing and especially drying this will only ever be a dream.
Halogenated hydrocarbons are the solvents of choice for vapour degreasing and cleaning. The process is essentially simple. A tank with a sump to contain the solvent, heaters at the base and condensation coils around the top section to control the height of the vapour is all that is needed. When heated in the sump halogenated solvents produce, in most cases, a saturated vapour between 3 and 4 times heavier than air at a temperature greater than the ambient temperature of the parts to be cleaned. This allows the solvent vapour to condense on the surface of the parts. The condensate dissolves the contaminants such as oil, greases, flux, and soils returning the used solvent into the sump of the machine for recycling into vapour which continuously condenses onto the parts until they have achieved vapour temperature when, with no further condensation, the process is complete. Parts removed from the cleaning machines are very clean, warm and dry.
The most common halogenated solvents, in use for commercial purposes, are non-flammable so present no risk in this process. Perchloroethylene, used mainly for dry cleaning, methylene chloride previously used widely in paint strippers, 1,1,1- trichloroethane and trichloroethylene used for vapour degreasing were the original materials used based on chlorine chemistry. However continuing concern about the environmental impact and danger to operators by exposure to chlorine-based solvents, especially trichloroethylene, has led to a continuing search for safer alternatives, such as ProSolv 5408e, a trans-1,2-Dichloroethylene based solvent mixture that is non-flammable.
As with all legislation for chemical use regulation and restrictions drive development of associated processes and equipment. The most important developments in vapour degreasing cleaning machines to use solvents for vapour degreasing use two different approaches and raise difficult questions as to which is the best most economical and simplest in use.
The single tank hermetically sealed machines favoured by mainly German manufacturers uses a process tank to contain the solvent and a separate storage tank/vapour generator. Baskets with parts to be cleaned are loaded from the top and lowered into the process tank. A lid then closes over the tank and is hermetically sealed. Solvent is pumped into the process tank. Baskets are immersed in the solvent where agitation, ultrasonics or pumped liquid is circulated through the parts. When the immersion process is complete solvent is pumped to the storage tank and vapour fed to the process tank from a vapour generator for rinsing and drying. Condensing coils/panels controlling the vapour height are linked to coils located within the vapour zone which, when the cycle is complete, collapse the vapour. The process tank is emptied. The saturated air/solvent from the process tank is then recycled through carbon absorption units to remove traces of solvent from the air until the concentration is below 2 grams per cubic meter when the lid opens automatically for the basket of parts, clean and dry, to be removed and replaced with a further basket.
Variations within the hermetically sealed tank are possible using sprays of cold or hot condensed solvent, immersion with or without ultrasonics and revolving baskets to cover most of the problems experienced when processing machined and fabricated parts. Continuous external distillation of the contents of the vapour generator is also an option depending on contamination.
The alternative technology is much simpler and cheaper and less time consuming using well trained techniques. This is favoured by UK based manufacturers. The multilevel system shown in the diagram uses a standard vapour degreasing tank design with a sealed loading section above the process tank.
Work baskets are fed to the load section from a hoist or conveyor. The loading door is then pneumatically sealed to hermetically isolate the process. The sealing lid on the process tank is opened and the basket lowered into the cleaning tank which can be simple vapour degreasing with vapour generator below or an offset generator can be used with the lower section being filled with clean solvent for immersion cleaning with or without ultrasonics or power sprays. Revolving baskets can also be added to improve cleaning in blind or through holes or oil ways in castings and fabrications.
When the process is complete the basket rises to the freeboard area where the condensation coils are located, and parts are allowed to drain and dry. The tank seal opens to allow the basket into the load section while the lid closes again across the process tank. A fan is then activated which produces a negative vacuum in the load area. The loading door is then partially opened to allow a flow of air through the loading section which is exhausted to atmosphere or can be recycled through carbon absorption systems if no external exhaust is preferred. As baskets entering the loading space contain parts drained and dried only very small amounts of solvent are carried in the exhausted air which is monitored to ensure compliance with local legislation. When this is achieved the door opens fully for removal of basket. The loading section can be fitted with top or side sealed doors allowing baskets to flow through on conveyor systems or be loaded from hoists. No solvent enters the work area. Both processes will produce parts cleaned to the highest standards but the choice of which offers the best solution needs a little more consideration.
The single tank process is complicated with the need to move liquids in the machine. It is relatively slow as the carbon adsorption process needs to remove high levels of solvent from the recirculated airstream from the process tank. This is inefficient as adsorption rates for carbon fall rapidly with increasing saturation. Final levels of solvent in the tank when the lid opens will be dragged into the workshop and the area in which the operator is working. Long process cycles reduce throughput.
The simpler multilevel systems where movement of liquids is not required are more efficient and offer much faster process times. Cost of manufacture is also cheaper as no liquid movement is involved. The extracted loading section ensures no leakage of solvent into the work area which offers complete safety for operators and factory staff. The disadvantage of the multilevel machine is the height of the equipment compared to the single tank machine. This will often require the equipment be installed in a pit for easy access.
Both designs of process machines fully comply with the emission regulations of the UK, EU and U.S authorities. Which to choose will depend on many factors which should be discussed with both the equipment and solvent suppliers who have the experience to advise on which offers the best process for the application. Equipment and solvent must work together and it is advisable to ensure that the suppliers work closely together to offer a package with high levels of responsible care and product stewardship to ensure the best and safest installation.
The vapour cleaning process still gives the highest levels of economical cleaning with minimum energy usage, low footprint on the factory floor, safety for the operator, and high production rates with low solvent usage or environmental impact. With the new generation of sealed cleaning machines its future as the process of choice is assured.
Envirotech Europe supplies three distinct products that use this process and we are happy to advise you on the best solution to suit your needs. Please visit our website to find out more about ProSolv 5408e, ProSolv and EnSolv® CC-A.
Image of Solvac hermetically sealed equipment by kind permission of CC Hydrosonics Ltd.
FURTHER INFORMATION
Please visit our website www.envirotech-europe.com for information about other uses and applications for our vapour degreasing and cleaning products.
Visit www.envirotech-europe.com/applications-and-case-studies for information about uses and applications for all EnviroTech Europe products.
For more advice, please telephone us on +44 (0) 20 8281 6370 or use our contact form. All products are supplied and supported by EnviroTech Europe Ltd. Manufactured in the United Kingdom and available on short delivery times through our dedicated team of distributors worldwide.
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Electrical corrosion protection
Electrical corrosion protection – Prevent hydrogen sulphide corrosion in electrical and electronic equipment
Super CORR A is a proven and cost-effective way to prevent or inhibit corrosion from destroying electronics and electrical components. Adverse work environments where corrosive gases such as hydrogen sulphide are found, can cause severe corrosion and rapid deterioration of electronic components and equipment, including connectors and switches.
Lost productivity and revenue caused by plant and equipment downtime
Corrosion, in its many forms, costs both private and public sectors hundreds of billions of Euros a year to repair or replace electrical, electronics, or avionic components because of failures caused by corrosion. While all metals corrode, due to a number of different factors, there is no simple or single solution to the overall corrosion problem. However there are some very cost effective and proven ways to prevent corrosion and failures caused by corrosion and thereby reducing or eliminating associated costs and increasing safety which should be foremost in the mind set of any preventative maintenance programme manager.
Super CORR Awas specifically designed to lubricate and prevent corrosion in electrical fittings and connectors; electrical and avionic harness assemblies and connectors; electrical and electronic switches; close tolerance and dissimilar metal components; lighting connectors and sockets. A unique non-flammable “self-healing” ultra-thin film lubricant with a proprietary corrosion preventive compound that will not harden or crack, is not a wax or oil-based product and is formulated without sulphates, chlorides or halogens.
Super CORR A inhibits corrosion caused by exposure to both fresh and salt water moisture as well as the corrosive vapours from Sulphur dioxide (SO2), Nitrogen dioxide (NO2), Hydrogen Sulphide (H2S), Ammonia (NH3), and Chlorine (CL12) based gases found in waste water and sewer treatment plants, pulp and paper mills and plants, chemical and petroleum plants, maritime industry, aircraft/airline industry, military equipment including ships, aircraft, and rolling stock, auto industry, farming and agriculture industry, and the list goes on.
Super CORR A extends the working life of electrical components and systems and other critical items by preventing the deterioration and/or failure caused by corrosion and can significantly reduce downtime, operating and maintenance costs as well as enhance safety. An ultra-thin film, water displacing lubricant and corrosion inhibiting compound Super CORR A has undergone extensive testing by Battelle Labs as well as the U.S. Air Force and meets MIL-DTL-87177B (revised MIL-L-87177A) specification. SuperCORR-A is used by NATO (NATO NSN 8030-99-226-6966) to protect avionic, electrical, electronics, electrical switches and connectors and components from corrosion in both the military and civilian aircraft. Savings for the U.S. government alone is estimated to be in excess of $50 million per year.
Super CORR Aprovides a superior lubrication coefficient and protects components against moisture, wear, general and fretting corrosion, surface static electricity, corona, and other electromigration problems. The super thin non-flammable lubricant film is only 7 microns (0.00028 inch) thick and is formulated to meet the RoHS directive. It is unexcelled in preventing deterioration and contamination on all surfaces of electronic equipment.
The question for you is: What is the cost of NOT using Super CORR A in your preventative maintenance programme?
FURTHER INFORMATION
Please visit our website https://www.envirotech-europe.com/supercorr-a for for information about other uses and applications for Super CORR A.
Visit www.envirotech-europe.com/applications-and-case-studies for information about uses and applications for all EnviroTech Europe products.
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ProSolv®5408e vapour degreasing solvent cleaner for flushing refrigeration pipeline systems
Vapour degreasing solvent cleaner for flushing refrigeration pipeline systems
Concerns connected with the challenging environmental profile of traditional refrigerant gases have led to changes in legislation which are a driving factor in phase-outs and bans on the use of some gases to remove the older materials typically with high ozone depletion (ODP) and global warming potential (GWP). Systems can be replaced or refurbished with new models using compressors able to use more sustainable and acceptable gases. The evolving trend to newer refrigerants continues as the chemistries develop. The refrigerant R-22, which itself was an improvement over earlier refrigerants, is phased out and replaced with R-410a and other alternatives based on HFOs are being marketed.
Retrofitting of current refrigeration systems to accommodate the new developments is not straightforward as most refrigerant gases are not cross-compatible, so the necessity to completely remove all traces of the older versions from the system, including refrigerant lines is essential.
Of course, where possible it’s best simply to replace existing lines with new ones. However, it’s not always possible to do this cost-effectively, especially when the old piping runs under floors or through walls. In such cases thoroughly flushing existing pipework is especially important because even tiny traces of impurities left in the lines can damage new equipment and lead to compressor failure.
THE PERFECT SOLVENT FOR FLUSH CLEANING REFRIGERATION PIPEWORK
Your first step to proper pipework flushing is to select the right solvent. The solvent you choose must be highly effective at dissolving oil grease and other contaminants, to ensure that all residue is removed from the pipes and must be sustainable, environmentally friendly and comply with current legislation.
ProSolv 5408e is the ideal solution to this problem with a profile of properties and advantages making it perfect as your solvent of choice for refrigerant pipeline flushing.
• No flash point Non flammable liquid.
• High specific gravity gives a high soil suspension loading.
• High solvency strength with a KB value of 98.
• Powerful cleaning agent that can flush lines fast, dissolving oil and grease releasing soils from the inner surfaces of pipelines and fittings
• Volatile for fast evaporation. Removing ALL solvent from the pipework after flushing is vital, very volatile so evaporates fast.
• Environmentally responsible. ProSolv 5408e is sustainable and kind to the environment with very low global warming potential, zero ozone depleting potential (ODP).
• Safe for operators when user conditions are followed.
• Economical as it is easily distilled for reuse. No testing or stabilisation required.
PROCEDURE FOR FLUSH CLEANING REFRIGERANT PIPELINES WITH ProSolv®5408e
Of course, simply replacing old piping is the only way to be 100 percent sure that your lines are clean. But in retrofit situations where complete replacement is not possible, flushing the lines with ProSolv 5408e solvent is the best alternative solution for the protection and long working life of your refrigeration system upgrade.
1 – Remove any obstacles. Any equipment and components such as valve, filters and expansion valves that might obstruct the line should be removed prior to the purge.
2 – Pre-flush. This will dislodge any loose debris from the sides of the lines enabling more effective use of the solvent, oil free air or nitrogen at 120 psi is recommended. It’s also good practice to oscillate the pressure to encourage dislodging of debris.
3 – Preparing the pipework. Reducing the length of piping can be more effective due to the pressure loss in long lengths. Section the operation into 15 metre lengths by cutting pipes where necessary. One end of the pipe must be fitted with a connector for the pipe to the nitrogen supply while the exit needs a restrictor valve to allow variable pressures to shock loose particles from internal walls.
IMPORTANT – Flushing with solvent. Refer to ProSolv 5408e Safety Data Sheets for advice on operator protection using solvents.
4 – Safe working. Full PPE with suitable eye protection goggles and gloves must be worn. Solvent fumes are heavier than air and exposure levels can easily be reached working in pits or enclosed spaces. Always institute a ‘buddy system’ and use air fed face masks with attached line.
5 – Delivering solvent. Use a drum pump electric or hand operated with a flexible tube connection for delivering the solvent to the open end of the pipe or tubing to flush the internal surfaces. Using a fresh drum of ProSolv®5408e connect drum pump and the delivery tube to the end of pipe/tube to be cleaned using a pre-fitted screwed or compression fitting.
6 – Drainage and Testing. The drainage end of the pipe or tube should be fitted with a flexible tube into a tank or drain sump allowing samples to be taken in a glass bottle or tube at regular intervals to be sure when no particles or soils are being expelled. The colour of the solvent will change as oil and soluble contaminants are removed and flushing must continue until the flow is totally clear and water white.
7 – Post-flush. ProSolv 5408e solvent is volatile so will dry completely using an oil free airline or nitrogen supply connected to the end of the cleaned pipe/tubing.
8 – A wipe of the pipe/tubing surface at the inlet and outlet using solvent saturated lint free cloth completes the cleaning. If not connected immediately to other parts of the system enclose both ends of cleaned item to prevent recontamination.
Used ProSolv 5408e should not be reused for flushing but can be recovered for reuse by a simple distillation process. Removal from site should use licensed disposal companies.
Further information:
For more information and advice please contact us by telephone on +44 (0) 20 8281 6370 or use our contact form. All products are supplied and supported by EnviroTech Europe Ltd. Manufactured in the United Kingdom and available on short delivery times through our dedicated team of distributors worldwide.
ProSolv 5408e is not just flushing refrigeration pipeline systems,
https://www.vapour-degreasing.com/prosolv5408e/ for information about other applications.
We can provide you with a Material Safety Data Sheets, independent laboratory reports, product samples and technical assistance.
For more information or advice please telephone us on +44 (0) 20 8281 6370 or use our contact form.
All products are supplied and supported by EnviroTech Europe Ltd. Manufactured in the United Kingdom and available on short delivery times through our dedicated team of distributors worldwide.
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Latest News
SuperCorr A defeats increasing gold prices for connector manufacture
Thinner plating caused problems with increased corrosion on USB connectors as gold coating thickness decreased with escalating gold prices.
A major company in the U.S. found that by using SuperCORR A it was able to prevent galling corrosion due to vibration on printed circuit leads and connectors.
They found that because of the advances in gold plating technology the plating thickness was being reduced over the base substrate metal of the connectors. The thickness of the gold plating became thinner and thinner over time. This thinner coating saved a lot of money as gold was and is becoming increasingly expensive. However the resulting reduced thickness of gold plating also resulted in failures caused by corrosion. Minute irregularities in the surface of the connectors base metal caused irregular or uneven wear of the connector causing the “high spots” on the connector to wear through the gold plating.
Using SuperCORR A prevented or delayed the corrosion and subsequent failures. However it must be recognized that
SuperCORR A is a lubricant with corrosion preventive compounds, and as is the case with all “lubricants” they will be worn off over time. Having said that, the Company also had SuperCORR A tested to see what the “life” of the lubricant was in a “rub test”. The typical test is 20,000 cycles, i.e. unplug, plug in is one cycle. The test results demonstrated that after 20,000 cycles there were no failures. It was decided to take it one more step and run the same tests for 200,000 cycles. The results again showed no indications of galling or scoring on the USB connectors at all. In fact they commented that the USB connector looked as good as new.
We can provide you with a Material Safety Data Sheets, independent laboratory reports, product samples and technical assistance.
For more information or advice please telephone us on +44 (0) 20 8281 6370 or use our contact form.
All products are supplied and supported by EnviroTech Europe Ltd. Manufactured in the United Kingdom and available on short delivery times through our dedicated team of distributors worldwide.
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Corrosion Control
Corrosion is a serious problem for industry and governments worldwide. Most people associate corrosion with rust, which only happens in things made of ferrous metals such as steel girders, ships, iron pipes, steel reinforcement rods, and steel tanks and is the reason metals deteriorate and fail.
Ferrous and non-ferrous metals corrode on contact with both fresh and salt water as well as water vapor. They will also corrode when they come in contact with chemicals, liquid acids as well as acidic vapors, salts and bases, and bacteria.
Read our article “Corrosion Control Solutions – A Solution To A Costly Problem” for more information about the enormity of the costs involved in failing to prevent corrosion.
We can provide you with a Material Safety Data Sheets, independent laboratory reports, product samples and technical assistance.
For more information or advice please telephone us on +44 (0) 20 8281 6370 or use our contact form.
All products are supplied and supported by EnviroTech Europe Ltd. Manufactured in the United Kingdom and available on short delivery times through our dedicated team of distributors worldwide.
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