Diaphragm Pump
Pumps & Valves
Diaphragm Pump
1. Product Overview
The diaphragm pump is a positive displacement pump that transfers liquid through the reciprocating motion of a flexible diaphragm inside the pump chamber. It consists of a pump body, diaphragm, drive mechanism, inlet/outlet valve balls and motor. The diaphragm fully isolates the pumped medium from the drive mechanism, ensuring leak-free operation.
Widely applicable to: transfer of flammable and explosive liquids, toxic and hazardous media, high-viscosity materials, and solid-laden slurries.
Key features: zero leakage, strong self-priming, dry-run capability, handles solid-containing slurries, easy maintenance.
2. Working Principle
The motor drives the diaphragm back and forth through a crank mechanism (the pneumatic version is driven by compressed air). As the diaphragm moves forward, the chamber volume decreases, the discharge ball valve opens and liquid is expelled while the suction valve closes; as it moves backward, the volume increases and negative pressure draws liquid in through the suction valve while the discharge valve closes. Continuous reciprocation delivers the liquid in a pulsating flow.
3. System Classification
By Drive Type
| Type | Features | Typical Applications |
|---|---|---|
| Electric | Motor driven, stable flow | Continuous chemical process transfer |
| Pneumatic | Air driven, explosion-proof without electricity | Hazardous areas, temporary sites |
| Hydraulic | Hydraulic-oil driven, high pressure | High-pressure transfer, metering duty |
By Diaphragm Material
| Type | Temperature Range | Suitable Media | Remarks |
|---|---|---|---|
| PTFE | ≤120℃ | Strong acids and alkalis | Best chemical resistance |
| NBR | ≤80℃ | Petroleum products, oils | Good oil resistance |
| EPDM | ≤120℃ | Weak acids/alkalis, water | Good aging resistance |
| FKM | ≤150℃ | Aggressive media, high temperature | Good all-round performance |
| PU | ≤60℃ | Abrasive slurries | Good wear resistance |
4. Detailed Technical Parameters
4.1 Typical Specification Table
| Drive Type | Flow (L/min) | Max Discharge Pressure | Max Suction Lift | Port Size | Drive Power |
|---|---|---|---|---|---|
| Electric | 5～1000 | 0.7～1.2MPa | 5m | DN10～DN80 | 0.37～7.5kW |
| Pneumatic | 5～1200 | 0.84MPa | 7m (dry) | DN10～DN100 | Air consumption 0.2～8m³/min |
| Hydraulic | 1～500 | 10～35MPa | 5m | DN10～DN50 | 1.5～15kW |
Note: the flow of pneumatic pumps varies with air supply pressure; rated flow is based on a 0.7MPa air supply.
4.2 Design Conditions & Performance Indicators
| Parameter | Specification |
|---|---|
| Pulsation rate | Approx. ±15% (reducible to ±3% with a pulsation damper) |
| Self-priming lift | Electric 5m / pneumatic 7m |
| Dry-running capability | Short-term dry running permitted (≤5 min) |
| Solid handling | Particles up to approx. 15mm |
| Noise | Pneumatic ≤85dB(A) (with muffler) / electric ≤75dB(A) |
4.3 Electrical Parameters
| Region | Voltage | Frequency |
|---|---|---|
| China/Russia/Central Asia | 380V | 50Hz |
| Middle East/Southeast Asia/Africa | 400V / 415V | 50Hz |
| South Korea | 380V | 60Hz |
| Americas (if required) | 440V / 480V | 60Hz |
Pneumatic pumps require only compressed air (0.2～0.7MPa). For electric pumps, please specify voltage and frequency.
5. Core Component Selection
| Component | Typical Brands | Features & Applications |
|---|---|---|
| Diaphragm | Imported / premium domestic | PTFE for corrosion resistance; NBR for oil service; PU for abrasion |
| Valve ball/seat | Imported / domestic | Ceramic for wear resistance; PTFE for corrosion resistance |
| Air valve | SMC, Airtac | For pneumatic pumps |
| Motor | ABB, Siemens | For electric pumps, explosion-proof optional |
| Muffler | Standard | Exhaust silencing for pneumatic pumps |
6. Typical Application Fields
Chemical: transfer of acids, alkalis and toxic solvents; Environmental: sewage, sludge and chemical dosing; Petroleum: oil transfer and crude loading; Mining: slurry and tailings transfer; Food: transfer of food-grade raw materials (with food-grade diaphragm).
7. Design Standards & Certifications
| Standard | Description |
|---|---|
| GB/T 7782-2020 | Technical conditions for metering pumps |
| ISO 9001:2015 | Quality management system |
| CE / EAC / GOST-R | Available upon request |
| ATEX | Available for explosive atmospheres |
8. Customizable Options
| Option | Details |
|---|---|
| Diaphragm material | PTFE/NBR/EPDM/FKM/PU |
| Pump body material | Cast iron/aluminum alloy/304/316L/PP/PVDF |
| Drive type | Electric/pneumatic/hydraulic |
| Configuration | Pulsation damper, back-pressure valve, relief valve, flow regulator |
| Explosion-proof requirements | Ex-proof motor / pneumatic (intrinsically safe) |
| Connection | Flange/thread/tri-clamp |
9. Warranty Terms
| Equipment Status | Warranty Period | Warranty Scope |
|---|---|---|
| New equipment | 12 months | Pump body, drive mechanism, valves (diaphragm excluded) |
| Refurbished equipment | 6 months | Pump body, drive mechanism, valves (diaphragm excluded) |
| Idle equipment (as-is) | 3 months | Main functional parts |
Note: the diaphragm is a consumable wear part; damage from normal wear is not covered by free replacement.
10. Packaging and Delivery
| Item | Packaging Method |
|---|---|
| Pump body | Wooden case |
| Motor / air valve | Wooden case |
| Spare diaphragm / valves | Carton, shipped with the main unit |
| Accessories | Wooden case or carton |
Container Estimation:
Small (≤1.5kW): approx. 30～50 units per 20'GP; Medium (1.5～7.5kW): approx. 10～20 units per 40'HQ
Installation: on-site guidance available.
11. Information Required for Quotation
Medium name, concentration, temperature, viscosity; solid particles (size and content); flow rate and discharge pressure; suction conditions (self-priming/flooded); corrosiveness; preferred drive type (electric/pneumatic/hydraulic); explosion-proof requirements; local voltage and frequency (for electric models); equipment condition preference (new/refurbished/idle); budget and brand preference; delivery terms (FOB/CIF/DDP); destination port or address.