Tips for Disassembly, Maintenance, and Repair of Air operated diaphragm pump
The pneumatic double diaphragm pump is a siphon-type pump driven by air pressure, with an internal check ball valve that achieves the check effect through the force of gravity and fluid pressure on the ball. When in operation, the pump maintains a pressure higher than the external environment and is commonly used for transporting chemical fluids. During disassembly, maintenance should consider factors such as the remaining pressure difference, the hazardous nature of the transported fluid itself, assembly tightness, and component orientation. The following are points to be aware of and maintenance techniques when disassembling and maintaining a pneumatic double diaphragm pump:
Proper protective measures: Before disassembling the pump, maintenance personnel should consider whether the transported fluid itself is hazardous. Please make sure to take appropriate safety precautions, wear protective equipment, and have a first aid kit prepared.
Release residual pressure: Before disassembling the pneumatic double diaphragm pump, it is crucial to fully release the pressure inside the pump and the pipelines. Pay attention to situations where the pump and pipelines may be blocked, as the inability to fully release the pressure can lead to possible spraying and hazards during disassembly. In such cases, exercise caution during disassembly and take necessary safety precautions. It is recommended to use a wrench to manually loosen the components slightly to release the pressure.
Screw disassembly techniques: It is advisable to first loosen the screws manually using a wrench before using air power tools for disassembly. This helps avoid potential damage to the threads due to vibrations caused by the direct use of air power tools. When tightening the screws, use a symmetric sequence and tighten them in stages. Ensure that the mating gaps are evenly sealed to prevent leakage or potential pump body rupture due to uneven stress distribution.
Pay attention to assembly sequence and direction: Some components within the pneumatic double diaphragm pump have fixed assembly sequences and directions. Incorrect assembly may cause the pump to malfunction or result in abnormal fluid transportation. It is recommended to refer to the disassembly diagram in the pump's operation manual before disassembling and familiarize yourself with the sequence and direction. (You can also refer to the video link below for reference.)
Maintenance of inlet/outlet pipes and ball valve components: Check for any blockages or adhesion in the pipelines and ball valve components (#6-#10). Use appropriate cleaning tools or solvents for cleaning, taking care not to damage the ball valve and seat, which could affect the check effect. If there is wear on the ball valve, ball cover, or ball seat resulting in loss of roundness, they should be replaced. Additionally, for the pipe sealing ring (#5), prepare a pointed screwdriver for disassembly and insert it from the bottom gap to lift it. Since the PTFE sealing ring is prone to deformation and lacks elasticity, it should be reinstalled in its original direction and position. If the deformation is too significant, resulting in a loss of sealing effect, it should be replaced.
Diaphragm component inspection: The diaphragm backing plate (#14) and the diaphragm itself (#15/16) may deteriorate or corrode due to the characteristics of the fluid. Verify the flexibility or color change of the diaphragm to determine if it should be replaced in advance. Additionally, if the fluid contains sharp impurities or particles, the diaphragm may develop dents, cuts, or even rupture under the reciprocating squeezing action. It should be regularly replaced based on usage conditions to prevent fluid from leaking into the air chamber, which could damage other components and increase maintenance costs.
Pneumatic valve (sequential valve) maintenance: After disassembly, clean the surface of the components from any oil contamination. Then, check the sealing ring (#37/38) and the main components of the air valve (#35/36/53/54) for any signs of wear. If there are noticeable damages, dents, or scratches, they should be replaced immediately to prevent abnormal pump operation due to air leakage. If there are no issues, apply a thin layer of lubricating oil (pressure and temperature-resistant grease) evenly on the aforementioned sealing ring and components before assembling them in the correct sequence and direction.
Pump air chamber maintenance: After disassembling the diaphragm, check if there is any oil contamination or accumulated water in the air chamber and clean it thoroughly. If fluid has entered the air chamber due to diaphragm rupture, causing corrosion or blockage, relevant components should be replaced promptly.
Diaphragm shaft and conversion valve component maintenance: After disassembly, clean the surface of the components from any oil contamination. Then, check the sealing ring, diaphragm shaft, and conversion valve components for any signs of wear. If there are noticeable damages, dents, or scratches, they should be replaced immediately to prevent abnormal pump operation due to air leakage. If there are no issues, apply a thin layer of lubricating oil (pressure and temperature-resistant grease) evenly on the aforementioned sealing ring and components before assembling them in the correct sequence and direction.
Muffler inspection: If the air quality in the vicinity of the air compressor or pump is poor, check if the muffler is severely soiled and causing exhaust blockage. Avoid pump malfunction or reduced performance due to inadequate exhaust.
Filter maintenance: If the pump is equipped with a filter, regularly inspect and clean the filter to prevent blockage or damage.
Regarding lubricating oil: When applying lubricating oil to components, ensure a moderate amount of oil is evenly applied to the surface. Avoid excessive lubricating oil that could block the gas passage and affect the normal operation of the pump.
In summary, proper inspection and maintenance of the pneumatic double diaphragm pump are crucial steps to ensure its smooth operation and prolong its lifespan. By implementing these maintenance measures, the pneumatic double diaphragm pump can continue to work efficiently in various applications, enhancing productivity and operational efficiency.
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