Analysis of common faults in the use of German Verder pneumatic diaphragm pumps

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A pneumatic diaphragm pump is a new type of conveying machinery and represents the most innovative pump design available in China at present. Using compressed air as the power source, it is capable of pumping out and sucking up various corrosive liquids, liquids containing particles, as well as liquids that are highly viscous, volatile, flammable, or highly toxic. 　　Pneumatic diaphragm pumps are available in four materials: plastic, aluminum alloy, cast iron, and stainless steel. Diaphragm pumps use NBR, neoprene, fluororubber, and PTFE depending on the different liquid media. To meet the needs of different users. Installed in various special applications to pump fluids that conventional pumps cannot handle, it has achieved satisfactory results. Of course, some failures are inevitable when pneumatic diaphragm pumps are in use. The common faults are analyzed as follows: 1. Reduced flow rate. This phenomenon generally occurs under the following circumstances: first, the diaphragm is stretched and deformed over a long period of time, resulting in a reduction in the volume of the material chamber. Second, the wear of the inlet and outlet check valves (plastic balls) has decreased. There may be strips that cause large particles to get stuck in the plastic balls. This causes the liquid at the discharge port to flow back during material suction, and it pushes the material back into the feed port again during discharge. 　　2. The pump will not move. There could be several reasons for this phenomenon. First, the valve core is severely worn and stuck. Second is the wear of the shaft sleeve of the central axis. The copper sleeve should be replaced at this time. Third, the screws at both ends of the central axis have fallen off. Fourth, both membrane layers are ruptured. Fifth, the diaphragm pump is inverted or placed flat. The valve spool cannot return to its original position. 　　3. The pump lacks power, resulting in a slower pumping speed. This phenomenon generally occurs in the following situations: one is a decrease in the air supply pressure. First, check the pressure on the intake pressure gauge; a normal pressure value is between 4 and 7 kilograms. Then check the opening position of the air supply valve; if the air supply is controlled by a solenoid valve, inspect whether there is any damage to the plastic valve element of the solenoid valve, which could prevent it from opening completely. Second, the silencer is clogged, preventing air from being discharged quickly, which results in a reduced pumping speed. Third, there is too much water or impurities in the compressed air. Blockage of the air inlet hole after entering the diaphragm pump’s valve, or jamming of the valve core. Fourth, the upper and lower end caps of the valve gear suffer damage and cause air leakage due to the constant impact from the valve spool over time. Fifth, air leakage occurs due to the wear of the four sealing rings on the internal central shaft of the pump. 　　4. The material contains impurities or oil stains. This is usually caused by a ruptured diaphragm. 　　5. Leakage of materials during import and export. First, the screw is not tightened properly; second, the ball seat is deformed or the O-ring is damaged; third, the pump casings at both ends are not aligned, causing them to tilt and resulting in the two discharge or inlet ports not being on the same plane.