【Wolm Vacuum Pumps – After-sales Maintenance】How to clean water ring vacuum pumps

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After operating for a long time, water ring vacuum pumps develop some dirt on both their exterior and interior. In such cases, it is necessary to clean them. Cleaning the exterior is relatively simple, while cleaning the interior of the pump is more difficult. Inside the pump, a lot of residual scale and impurities often accumulate due to inadequate operation; if the interior is not cleaned thoroughly or at all, it will affect the pump’s performance. So, how should we clean a water ring vacuum pump? 1. For the initial cleaning, recycled gasoline can be used to save costs; for subsequent cleaning, cleaning gasoline should be used, and finally, aviation gasoline is used to ensure thorough cleaning. Then carefully inspect the damage and scratches. 1. The water ring vacuum pump needs to have the debris accumulated in its pump chamber cleaned every month; this can be done by briefly opening the valve on the discharge line or briefly removing the drain plug. 2. Add nitric acid or other soluble substances, but they must be diluted; pure substances should not be used as this will directly damage the internal components of the water ring vacuum pump. Place it in a container and wait for about an hour, then rinse it thoroughly with clean water. 3. Carefully remove the nozzles and ducts inside the vacuum pump, disassemble it, and use clean cotton yarn, silk fabric, or waste paper to wipe away the grease from the interior of the pump as well as from the nozzles and ducts at various stages ； Soak the components in a sodium hydroxide solution with a concentration of 50–100 grams per liter, heated to 60–70°C, or directly use organic solvents such as carbon tetrachloride, vinyl trichloride, and propane for soaking. After that, rinse them multiple times with cold water, and dry them using hot air or in an oven. It is best not to use pure cotton yarn for cleaning the surface of the components, as fine fibers from the cotton could end up inside the pump. Be sure to dry the cleaned parts (by blowing air on them or wiping them with a silk cloth until they are dry), and cover them to prevent dust from accumulating. If there are components awaiting repair or processing, other components can be coated with clean vacuum pump oil to prevent rusting. 3. If rusted or burried parts are found, they can be gently polished using an oilstone or metallographic sandpaper to remove rust spots and burrs; care should be taken to maintain the smoothness and flatness of the parts. 4. Drain the old oil and debris from the oil drain hole, and pour in new oil through the intake port using a funnel (for cleaning purposes). Slowly rotate the pump by hand a few times before draining this oil as well. Repeat this process once or twice in the same way, and then new oil can be poured in for regular use. 5. If excessive scale accumulates in the water ring vacuum pump during operation, it should be flushed at regular intervals (usually every 5 to 10 days). First, it is rinsed with a suitable solvent (such as 10% oxalic acid or alcohol), and then washed with water. 6. All filters and strainers installed on the pipelines must also be cleaned or replaced periodically (once a month). The 4 pairs of oil passage holes, oil grooves, and gas channels should have any accumulated particulate impurities, dust, dirt, or oil residues removed completely; any hardened deposits in these areas should be gently scraped away. Finally, use compressed air to clear and dry the oil passages, making sure that no gasoline or solvents used for cleaning remain trapped in the grooves of these passages. It should be noted especially that the oil holes on some pump end caps are very small. To block it easily, it is necessary to ensure that the two oil holes are in communication with the hole of the oil valve adjustment screw. 7. When cleaning with compressed gas, personal protective equipment (such as goggles, masks, etc.) must be worn, and the discharged gas must be routed through designated ducts. When using chemical cleaners, it is necessary to pay attention to the warnings and instructions in the relevant safety materials. Chemicals must be compatible with the materials used, and care should be taken as chemicals may corrode the components inside the pump. 8. The next cleaning cycle must be determined based on the degree of scaling in the exhaust chamber of the water ring vacuum pump during the initial inspection, or the degree of clogging of the filters in the pipelines. Before cleaning a water ring vacuum pump, appropriate protective measures must be taken, such as wearing a gas mask, and then the cleaning process should be carried out using the correct methods. Since water ring vacuum pumps operate in harsh environments for extended periods of time and may be exposed to various chemicals, special cleaning methods are required: (1) Electrochemical cleaning: The metal parts to be cleaned are placed in a certain solution, and the parts are connected to either the positive or negative pole of a power source; meanwhile, a plate made of a specific material is connected to the other pole of the power source. By adjusting the voltage of the power source, a certain current density is achieved, which helps to remove oil and the oxide layer on the metal surface. (2) Acid and alkali etching treatment: After degreasing, an etching treatment is carried out to remove the oxides on the metal surface. For parts that have undergone heat treatment, oil residues are no longer present, so an etching treatment can be applied directly to remove the oxide layer formed after annealing. Etching is generally carried out in acidic solutions. The oxides of most metals, as well as the metals themselves, can undergo chemical reactions with acids at appropriate concentrations. Oxides react with acids to produce salts and water, while metals react with acids to yield salts and hydrogen gas. Part of this hydrogen gas gets adsorbed on the metal surface, which can make certain metals brittle. To prevent brittleness and excessive corrosion, corrosion inhibitors can be added to the etching solution, and the concentration and temperature of the etching solution should be controlled appropriately. (3) Ultrasonic cleaning: The principle of ultrasonic cleaning relies on the \"cavitation effect\" it creates in the medium; that is, the vibrations of ultrasonic waves cause changes in the density of the cleaning medium, thereby achieving the purpose of cleaning. Vibration causes the medium to become sparse at times and dense at other times; when it is sparse, temporary voids are formed ； The instantaneous impact force generated during closure can reach several atmospheres; this powerful force destroys the oil film on the surface of the object, causing it to separate from the surface along with contaminants and be washed into the solution. In short, after operating for a long time, water ring vacuum pumps need to be cleaned regularly in order to function better. Different vacuum pump components and different materials require specific cleaning methods. To ensure that there is no substance in the vacuum system that is prone to significant gas release, as well as to remove substances with high vapor pressures, thorough treatment is necessary. Especially since water ring vacuum pumps are used for biogas treatment over extended periods of time, dirt that can affect the operation of the equipment accumulates both on the surface and inside. If the interior is not cleaned thoroughly or properly, it will impact the performance of the pump. Note: A friendly reminder regarding the after-sales maintenance of Volm vacuum pumps: It is important to know the basic methods of maintenance. Each vacuum pump comes with detailed instructions for its maintenance. Generally, when a problem occurs with a vacuum pump, one should first compare these instructions with the maintenance procedures to determine whether improper or insufficient maintenance has led to the issue. Such problems can usually be resolved easily by following the usage instructions; they are quite simple to fix.