QBK Pneumatic Diaphragm Pumps also called Air operated double diaphragm pumps(AODD Pump)are rugged and durable self-priming, double diaphragm pumps, can handle any products that pours, form clean water to highly viscous, abrasive and chemically materials.
Simple structure, easy to use and maintenance, less wearing parts. It can be working under liquid and running dry as well.
Suction up to 5m, max discharge pressure is 7bar, max grain diameter is 10mm, max liquid viscosity is 10,000C.s.t.
Material:PP, Aluminum, Cast Iron, Stainless Steel. Diaphragm material:NBR, Viton, Teflon, FEP etc.
Flow rate can be controlled from zero to max flow by increasing or decreasing air pressure.
| Model | Diameter(mm) | Max Flow(L/min) | Suction(m) | Max Discharge Pressure(Bar) | Max Grain Dia(mm) | Max Air Consumption(L/min) |
| QBK-8 | 8 | 16 | 5 | 6.9 | 1 | 300 |
| QBK-10/15 | 10/15 | 20 | 5 | 6.9 | 1 | 300 |
| QBK-25 | 25 | 100 | 5 | 6.9 | 2.5 | 600 |
| QBK-40 | 40 | 140 | 5 | 6.9 | 4.5 | 600 |
| QBK-50 | 50 | 240 | 5 | 6.9 | 8 | 900 |
| QBK-65 | 65 | 280 | 5 | 6.9 | 8 | 900 |
| QBK-80 | 80 | 400 | 5 | 6.9 | 10 | 1500 |
| QBK-100 | 100 | 480 | 5 | 6.9 | 10 | 1500 |
QBK-25 Cast Iron Pneumatic Diaphragm Pump (AODD Pump): Comprehensive Product Guide
The QBK-25 Cast Iron Pneumatic Diaphragm Pump (AODD Pump) is a high-performance air-operated double diaphragm pump designed for reliable and efficient liquid transfer across a wide range of industrial and commercial applications. Constructed from robust cast iron, the pump is highly durable and resistant to mechanical wear, making it suitable for handling abrasive, viscous, and chemically aggressive liquids.
The pump operates on compressed air, delivering smooth, pulsation-free flow without electricity, which ensures safe operation in hazardous environments. Its energy-efficient design, corrosion-resistant components, and ease of maintenance make the QBK-25 Cast Iron AODD Pump a preferred choice for industries requiring dependable liquid handling solutions.
Durable Cast Iron Construction
Heavy-duty cast iron body provides mechanical strength and long service life.
Suitable for abrasive fluids and high-pressure applications.
Air-Operated Efficiency
Operates on compressed air, eliminating the need for electricity.
Safe for use in flammable or explosive environments.
Smooth and Consistent Flow
Pulsation-free operation reduces turbulence and backflow in pipelines.
Ideal for chemical, slurry, and industrial fluid transfer.
Versatile Applications
Handles a wide range of liquids including solvents, acids, alkalis, and viscous fluids.
Suitable for intermittent or continuous pumping tasks.
Low Maintenance Design
Minimal moving parts allow quick inspection and replacement of diaphragms, valves, and seals.
Reduces downtime and operational costs.
Energy-Efficient Operation
Optimized diaphragm movement reduces air consumption per unit of pumped liquid.
Efficient operation contributes to lower operating costs in industrial processes.
| Parameter | QBK-25 Cast Iron AODD Pump Details |
|---|---|
| Pump Type | Pneumatic Diaphragm (AODD) |
| Material of Construction | Cast Iron Body, Stainless Steel Wetted Parts |
| Flow Rate | 25 L/min (typical) |
| Maximum Pressure | 7 bar |
| Maximum Suction Lift | 6 m |
| Maximum Discharge Head | 20 m |
| Air Supply Pressure | 2–7 bar |
| Air Consumption | 3–5 m³/min |
| Viscosity Range | Up to 1000 cP |
| Fluid Temperature Range | -20°C to 80°C |
| Inlet / Outlet Connection | 1" BSP / NPT Threaded |
| Certifications / Standards | CE, ISO 9001 |
The QBK-25 Cast Iron AODD Pump meets global environmental and safety standards, ensuring sustainable and safe operation:
RoHS Compliance: Restriction of hazardous substances ensures environmentally friendly materials.
CE Certification: Confirms adherence to European safety and performance regulations.
ISO 9001: Quality management standard ensures reliable manufacturing processes.
Optional ATEX certification available for use in explosive environments.
By adhering to these standards, the pump supports eco-friendly and safe industrial processes, minimizing environmental impact while maintaining high operational efficiency.

Proper installation ensures optimal performance, longevity, and safety.
Verify the pump model and connection type.
Inspect all diaphragms, valves, seals, and fittings for integrity.
Ensure availability of clean, dry compressed air.
Place the pump on a stable and level surface to minimize vibration.
Secure the pump with appropriate bolts or brackets.
Avoid installation in areas with excessive dust, heat, or moisture.
Connect inlet and outlet pipes according to flow direction markings.
Use proper thread sealant or gaskets to prevent leaks.
Ensure straight pipe runs to reduce turbulence (minimum 3×DN upstream, 2×DN downstream).
Connect to a clean, lubricated, and regulated compressed air supply.
Install a filter, regulator, and lubricator (FRL) to maintain consistent pump operation.
Open air supply gradually to start the pump.
Monitor for leaks, abnormal noise, or pulsation during initial operation.
Adjust air pressure to achieve desired flow and efficiency.
Always follow the flow direction arrow on the pump body.
Prime the pump before operation to prevent dry running.
Use proper filtration to avoid abrasive particles damaging the diaphragm or valves.
Operate only within the recommended air pressure range (2–7 bar).
Wear personal protective equipment (PPE) such as gloves and safety goggles when handling hazardous liquids.
Ensure all connections are secure and leak-free before starting.
Disconnect the air supply and relieve pressure before maintenance or inspection.
Avoid using the pump for explosive or flammable liquids unless ATEX-certified.
Manufacturer provides technical guidance and support for installation, operation, and maintenance.
Assistance available for custom applications, troubleshooting, and spare parts selection.
| Problem | Possible Cause | Solution |
|---|---|---|
| Pump not operating | No air supply, blocked air line | Check air supply, clean filter, inspect tubing |
| Low flow or reduced output | Clogged inlet/outlet, worn diaphragm | Clean valves and tubing, replace diaphragm |
| Air leakage from pump | Damaged seals or fittings | Replace seals, tighten connections |
| Excessive noise or vibration | Improper mounting, cavitation | Reinstall securely, check suction, adjust air pressure |
| Pulsation in fluid flow | Air trapped or blocked discharge | Purge air, clear obstructions |
Daily: Inspect for leaks, monitor air supply, and check for unusual noise.
Weekly: Inspect diaphragms, valves, and seals for wear or damage.
Monthly: Clean internals and lubricate moving parts if applicable.
Annually: Replace worn diaphragms and valves, conduct efficiency tests.
The QBK-25 Cast Iron AODD Pump is suitable for a variety of industries and fluids:
Chemical Industry – Transfer of acids, alkalis, solvents, and aggressive chemicals.
Water and Wastewater Treatment – Dosing chemicals, sludge handling, and fluid transfer.
Food and Beverage Industry – Safe handling of syrups, juices, and other liquid ingredients.
Pharmaceutical Industry – Precise dosing and transfer of liquid medicines and solutions.
Industrial Manufacturing – Lubrication, chemical injection, and process automation.
Heavy-Duty Construction: Durable cast iron body for abrasive and high-pressure applications.
Air-Operated: Safe for hazardous or flammable environments.
Energy-Efficient: Optimized air consumption reduces operational costs.
Smooth Flow: Pulsation-free operation improves process stability.
Low Maintenance: Quick access to diaphragms, valves, and seals.
Global Compliance: CE, ISO, RoHS, and optional ATEX certification.
Versatile Applications: Suitable for chemicals, viscous fluids, and industrial liquids.
Pumps are packaged in protective foam and corrugated boxes.
Wooden crates for larger or export shipments.
Moisture-proof wrapping for long-distance transport.
Clear labels include model number, serial number, air pressure rating, and handling instructions.
Available via air, sea, or courier service.
Bulk shipping options and palletization available for distributors.
Packaging complies with international shipping standards.
The QBK-25 Cast Iron Pneumatic Diaphragm Pump (AODD Pump) delivers durable, reliable, and energy-efficient liquid transfer for industrial, chemical, food, and pharmaceutical applications. With its robust cast iron construction, smooth pulsation-free flow, air-operated safety, and low maintenance requirements, it is ideal for demanding liquid handling processes.
Whether for chemical dosing, water treatment, industrial automation, or abrasive fluid transfer, the QBK-25 AODD Pump ensures safe, efficient, and long-term performance, making it a trusted choice for global industries.
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