Air-Operated Double Diaphragm (AODD) Pumps
What are AODD pumps and how do they work?
What is an AODD pump?
An AODD pump is a pneumatically driven positive-displacement pump. Instead of using an electric motor to drive an impeller, it uses compressed air to alternately move two flexible diaphragms. This creates suction and discharge strokes that move liquid through the pump.
How an AODD pump works (step-by-step)
1. Compressed air enters the air valve and drives one diaphragm outward.
2. As that diaphragm moves, it pushes liquid out of its chamber through a discharge check valve.
3. At the same time, the opposing diaphragm moves inward, creating suction that draws liquid into the opposite chamber through an inlet check valve.
4. The air valve shifts, reversing the diaphragms, and the cycle repeats.
Because flow is created by diaphragm displacement and check valves, AODD pumps can often tolerate:
• intermittent running and frequent starts/stops,
• non-Newtonian or shear-sensitive fluids (with appropriate elastomers and valve choices),
• solids-laden liquids (within the pump’s valve/ball/seat limits and recommended particle sizes).
Key benefits of AODD pumps
Broad fluid compatibility
AODD pumps are available in multiple wetted materials (metals and plastics) and diaphragm/elastomer options, enabling compatibility with many chemical duties and abrasive services when correctly selected.
Simple, robust design
Fewer rotating parts means fewer components to wear in typical operation. In many AODD pumps, the primary wear/consumable items are the diaphragms and check valve components.
Intrinsically air-powered operation
Because they run on air, AODD pumps are widely used where pneumatic drive is preferred (for example, where electricity is inconvenient, or where operations favour air tools and air infrastructure).
Typical applications for AODD pumps
AODD pumps are widely used for:
• Chemical transfer (acids/alkalis/solvents) with compatible pump materials
• Wastewater, sludge and slurry handling (within solids-handling capability)
• Drum and IBC unloading
• Filter press feed
• Paints, inks, adhesives and coatings
• Food-related transfer where hygienic configurations are chosen (application dependent)
• General plant utility pumping where flexibility and reliability matter
(Exact suitability depends on fluid, temperature, solids content, required flow/pressure, and material compatibility.)
How to choose the right AODD pump
To size and select correctly, you typically need:
• Fluid type + concentration (chemical compatibility)
• Temperature range
• Desired flow rate
• Discharge pressure / backpressure
• Solids content and particle size (if applicable)
• Suction conditions (lift, flooded suction, line losses)
• Required certifications (e.g., ATEX where applicable)
Why buy AODD pumps from Triark?
A specialist focus on AODD pumps, spares and support
Triark positions itself as a long-established UK supplier of air-operated double diaphragm pumps, supporting customers with product selection and supply of pumps and spares.
Fast supply options
Triark highlights fast delivery options for pumps and spares, including next day delivery availability on its site messaging (stock and location dependent).
Aftercare: repairs and refurbishment
Triark offers pump aftercare services, and notes that a major service request is repair and refurbishment of AODD pumps—with claimed turnaround targets of under 48 hours (or 24 hours with a premium) for certain repairs.
(As with any service, turnaround depends on pump condition, required parts and workload—your page can add your current service SLA if you want it to be stricter.)
AODD spares: what wears, what to keep in stock
For most AODD pumps, the main consumables are:
• Diaphragms
• Check valve balls/discs
• Valve seats
• O-rings / seals (where used)
Triark’s own guidance also highlights valves, seats and diaphragms as key consumables and notes that selecting the appropriate components is important.
Practical tip: If uptime is critical, keep a simple spares kit aligned to your duty (correct elastomer/valve material) so you can service quickly without re-qualifying materials.
