Diaphragm
The heart of the pump. Made of PTFE, EPDM or NBR; flexible membrane that pushes and pulls the fluid.
Technical Guide
Diaphragm Pump
What is it?
Comprehensive introductory guide to the working principle, components and application areas of the AODD pump.
Basic Knowledge
How Does an Air Diaphragm Pump Work?
The Air-Operated Double Diaphragm pump (AODD) is a type of pump that operates with compressed air, is self-filling and resistant to dry running. It has two symmetrical pump chambers; each chamber has a diaphragm and the diaphragms move alternately to push the fluid.
The central air distribution valve directs the compressed air to both sides in turn. The left diaphragm is pushed forward while the right diaphragm retracts; the fluid is directed through the suction and discharge valves. Thanks to this mechanism, the pump produces a smooth, pulsating flow.
- No electricity required - just compressed air
- Dry-run resistant, self-refillable
- Suitable for fluids containing solid particles
- Pulse flow - preferred for precise chemical dosing
- Safe in explosive environment (with ATEX option)
Pump Anatomy
Diaphragm Pump
Basic Parts
Ball Valve
Non-return valve that controls the suction and discharge directions. Also known as a ball or ball valve.
Air Distribution Valve
Automatic transmission valve that directs compressed air sequentially into both pump chambers.
Body
It is selected according to the fluid and environment with PP, PVDF, aluminum or SS316L options.
Advantages
Why Is Diaphragm Pump Preferred?
A diaphragm pump is a positive displacement pump that draws and discharges liquid through the back-and-forth movement of a flexible membrane. In the air-operated double diaphragm (AODD) version, this movement is provided solely by pressurized air; no electric motor or mechanical shaft is required. This fundamental characteristic makes AODD pumps safely usable in explosive environments, wet areas, and sites with limited electrical infrastructure. Pumpport responds directly to domestic industrial needs by designing and manufacturing this technology in Turkey.
Air-operated diaphragm pumps operate on the principle of a central air distribution valve (ADV) that connects two pumping chambers. While one side performs suction, the other side performs discharge; the rollers automatically reverse. Thanks to this synchronized operation, the flow is continuous and nearly pulse-free. AODD pumps can withstand dry running without damage; this characteristic provides a critical advantage that protects pump life during process errors and level fluctuations.
Plastic (PP, PVDF) and metal (aluminum, SS316) body options are designed according to different chemical environments and pressure requirements. Models with PP bodies stand out in acid and base transfer, while models with stainless steel or aluminum bodies are preferred in high pressure and abrasive fluids. The selection of diaphragm material such as PTFE, EPDM, Neoprene or Santoprene is the key factor determining operating temperature and chemical compatibility. The Pumpport product family presents this diversity under one roof, enabling engineers to meet all process points with a single supplier.
- Cordless operation — Compressed air alone is sufficient; operates safely without generating sparks in ATEX zones
- Dry-run resistant — Pump remains on standby without damage when fluid runs out
- Wide chemical compatibility — PP, PVDF, SS316 body; PTFE, EPDM, Santoprene diaphragm options
- Self-priming — In dry conditions 4–5 m, in wet conditions up to 6–8 m suction height
- Quick disassembly-assembly — Diaphragm replacement is completed without requiring special tools thanks to the modular structure
- Linear flow control — By restricting air pressure, the flow rate can be precisely adjusted from zero to maximum.
Series Comparison
Which Diaphragm Pump
Is Right for You?
| Feature | Plastic (PP) | Metal (PA) | Hygienic (PH) | High Pressure |
|---|---|---|---|---|
| Body Material | Polypropylene (PP) or PVDF | Aluminum or SS316 | Electropolished stainless steel 316L | SS316 + pressure booster |
| Maximum Pressure | 8,4 bar | 8,4 bar | 8,4 bar | ~16 bar (with 2:1 booster) |
| Maximum Temperature (body) | ~65°C (PP) / ~93°C (PVDF) | Diaphragm attached | Diaphragm attached | Diaphragm attached |
| Diaphragm Temperature Range | PTFE: 4-177°C / Santoprene: -29-104°C | PTFE: 4-177°C / Viton: -40-177°C | PTFE 4-177°C | PTFE / Santoprene |
| Typical Application | Acid, base, chemical transfer | General industry, oil, solvent | Food, medicine, cosmetics | Filter pressure feed, paint |
| ATEX Compliance | Optional (conductive PVDF) | Yes | Yes | Yes |
| Outstanding Advantage | Low cost, corrosion resistance | Mechanical strength, long life | FDA-compliant CIP/SIP compatible material | High outlet pressure, compact |
Select by Pump Type
Which Diaphragm Pump Is Right for You?
Diaphragm Pump Operating Principle
Suction and discharge stroke step by step, AODD/EODD comparison, material selection guide.
ReviewPlastic Diaphragm Pump
PP or PVDF body, 7 bar, 16–894 lpm. First choice if chemical resistance is a priority.
ReviewMetal Diaphragm Pump
AL / Cast Iron / SS316, 8.4 bar, −18°C. For heavy industry and petrochemistry.
ReviewHygienic Diaphragm Pump
AISI 316L, CIP/SIP compatible. FDA approved solution for food, pharmaceutical and cosmetic processes.
ReviewHigh Pressure Diaphragm
8.4 bar, 160 m delivery head. For filter press feeding and long line transfer.
ReviewElectric Diaphragm Pump
380V electric drive, no compressor required. For 250-500 lpm constant flow requirement.
ReviewSectoral Use
Diaphragm Pump
Application Areas
Chemical Industry
Pumpport pumps with PP or PVDF bodies safely convey corrosive fluids such as sulfuric acid, hydrochloric acid, and caustic solutions. Conductive body and antistatic diaphragm options prevent static electricity accumulation in flammable solvent transfer.
Food & Hygiene
The Hygienic (PH) series is used in the transfer of milk, fruit juice, sauce and syrup with FDA compliant materials and internal geometry that leaves no dead spots. The electropolished SS316L surface is fully compatible with CIP/SIP processes.
Mining & Mineral Processing
AODD pumps transfer mining slurries with high solids content and clay suspensions without clogging risk. Large internal passage diameter and powerful ball-valve system provide long service life in abrasive pulps.
Petrochemistry
Metal-bodied, ATEX-certified Pumpport models are preferred for the safe transfer of crude oil, diesel, solvents and oil derivatives. The non-electric operating principle directly supports zone-compliant installation.
Pharmaceuticals & Biotechnology
PH series models with PTFE diaphragm; minimize the risk of cross-contamination in the transfer of active pharmaceutical ingredients (API), gels, creams and solutions. The dead-leg-free design provides critical advantage in sterile processes.
Waste Water & Environment
Treatment plants benefit from a reliable solution for transferring active sludge, polyelectrolytes, and flocculants. Its dry-run resistant design protects pump life in wastewater lines where level fluctuations are intense.
Our Products
Diaphragm Pump Models
Frequently Asked Questions
About Diaphragm Pump
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Centrifugal pumps operate in continuous rotary motion and are suitable for clean and low viscosity fluids. Diaphragm pumps, on the other hand, are positive displacement, self-filling, dry-running and preferred for particulate or viscous fluids.
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Standard AODD pumps operate with a 1:1 air-to-liquid pressure ratio; that is, approximately 6 bar of liquid pressure is achieved with 6 bar of air pressure. High-pressure diaphragm pumps can reach up to 8.4 bar, while booster system models can reach up to ~16 bar.
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Choose a diaphragm pump if: (1) the fluid contains particles, (2) there is a risk of dry running, (3) there is no electricity in an explosive atmosphere, (4) low flow precision dosing is required, (5) corrosive chemicals are to be transported.
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Diaphragm life varies according to fluid type, working pressure and diaphragm material. Under normal conditions a PTFE diaphragm can serve between 5,000-10,000 hours. Chemical damage or dry running significantly shortens this period.
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Pneumatic diaphragm pumps can operate over a wide range from low viscosity solutions to high viscosity pastes and adhesives. Standard models can be used in fluids with viscosity up to 50,000 cPs. As viscosity increases, the required air pressure also increases, so it is recommended to specify the fluid viscosity for proper model selection.
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AODD pumps can be used in dosing applications as they provide flow rate control by adjusting air pressure or stroke speed. However, for critical dosing points requiring precision of ±1% or less, a combination of peristaltic or piston pumps may be more suitable.
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Air-operated AODD pumps do not generate sparks by their nature. ATEX-certified models are suitable for use in explosive atmospheres: Gas Group for Zone 1 and Zone 2, Dust Group for Zone 21 and Zone 22. During installation, conductive/antistatic material selection and static grounding line must be applied without fail.
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The main elements that should be checked during routine maintenance of AODD pumps are the diaphragm, ball valves, valve seats, and air distribution valve (ADV). The modular design of Pumpport pumps allows the entire diaphragm assembly to be replaced within 20-30 minutes without requiring special tools.