When selecting a miniature diaphragm pump, it will focus on fluid parameters, such as working pressure, flow. and electrical parameters, such as drive voltage, control signals, and electromagnetic interference are also important. It also needs to consider application characteristics, such as medium composition, flow pulsation. Reliability requirements and costs are also key factors. All the above factors will have a huge impact on the selection results and actual application.
Here is the most important Tips as a selection guide:
- Considering Working Pressure
- Maximum Flow Rate and Actual Flow Rate
- Gas Tightness and Leakage
- Driving Voltage
- Control signal
- Electromagnetic interference
- Flow Pulsation
- Start with Load
- Medium Composition
- Reliability of Pump System
- Cost of Miniature Diaphragm Pumps
- Noise Level When Miniature Diaphragm Pumps Working
- Vibration When Pumping
1. Considering Working Pressure
Some of the miniature diaphragm pump work in the negative pressure range, that is, the diaphragm vacuum pump. Some can work in the negative pressure range or the positive pressure range and are called diaphragm compressors. Besides paying attention to the maximum vacuum and maximum pressure that the pump can reach when selecting the model, what is more important is the actual operating point, that is, the actual pressure of the pipeline during operation.
2. Maximum Flow Rate and Actual Flow Rate
Diaphragm pump manufacturers use different methods to identify the flow rate. Generally, when the flow rate is at room temperature and pressure, the flow rate measured with a rotameter is called the peak flow rate. Under normal temperature and pressure, the flow rate measured with a soap film flowmeter is called the average flow rate. In practical applications, pumps often work under a certain pressure, and the flow rate under a certain pressure is different than that under normal temperature and pressure. The flow rate under a certain pressure can be obtained by querying the flow-pressure curve.
3. Gas Tightness and Leakage
The factors that affect the gas tightness of miniature diaphragm pumps can be divided into external leakage and internal leakage. External leakage means that the gas in the pipeline and pump cavity leaks to the outside of the pipeline and pump cavity. External leakage is generally determined by the reliability of the pipeline connection and the sealing structure of the pump. The internal leakage refers to the leakage from the outlet of the pump to the inlet of the pump, which is a kind of fluid refilling. The internal leakage performance is determined by the internal check valve structure of the pump.
4. Driving Voltage
For miniature diaphragm pumps, common working voltages include 12 volts DC, 24 volts DC, and 5 volts DC. There are also models that can be powered by a wide voltage. That is, models that can work normally within a wide voltage range . Wide-voltage power supply can bring better electrical compatibility.
5. Control signal
Most of the current high-end diaphragm pumps are driven by brushless motors, so they have the ability to accurately adjust the speed and start-stop control. Users can control the brushless motors through digital and analog signals. With the cooperation of the sensor, accurate fluid transmission can be realized. More importantly, by controlling the speed through the signal, the flow rate of the pump can be matched with the actual demand, and lower noise and power consumption can be achieved.
6. Electromagnetic interference
The pump, the entire system and equipment may be sensitive to electrical radiation from AC or DC motors. The European Union has formulated standards such as EN61000 to solve the problems of electromagnetic interference and electromagnetic compatibility of pumps.
The reciprocating diaphragm will bring pulsating flow. In applications that are sensitive to pulsation, user can use dual-chamber or multi-chamber pumps, adjust the volume and connection of the pipeline, install dampers or silencers, thereby effectively eliminate flow pulsation.
8. Start with Load
the miniature diaphragm pump can work in a wide pressure range, but when the pump needs to be restarted after it stops under a certain pressure, it needs to overcome greater resistance, so when it needs to be restarted under pressure, it needs to get the on-load restart pressure parameters of the pump to ensure stable and reliable repeated restarts.
9. Medium Composition
Many customers choose micro diaphragm pumps for reasons of corrosion resistance. When transmitting corrosive chemical media, it is necessary to conduct a chemical compatibility analysis on the materials of the pump and pipelines to determine whether the pump cavity, elastic components, and fluid pipelines are different. It will react chemically with the conveyed medium.
10. Reliability of Pump System
The reliability of the pump needs to be evaluated from multiple dimensions, such as the reliability of starting, such as the above-mentioned starting with load and starting at low temperature. The second is life, including motor life, continuous working life under no-load, continuous working life under maximum load, etc.
11. Cost of Miniature Diaphragm Pumps
The cost of a pump is closely related to its application scenarios. In particular, it is necessary to consider both the purchase cost and the maintenance cost, and comprehensively consider the price and life of a pump and whether its life is consistent with the maintenance cycle and cost required by the application. Match
12. Noise Level When Miniature Diaphragm Pumps Working
Low noise is also a major feature of miniature diaphragm diaphragm pumps. In some special applications, such as some medical equipment, the overall noise needs to be less than 50 decibels. If lower noise is required, you need to choose a specially designed low Noisy diaphragm pump. For example, the flow channel is specially designed to reduce fluid noise. Optimize the motor and transmission structure to reduce mechanical noise.
13. Vibration When Pumping
The reciprocating diaphragm will bring mechanical vibration. In the application of some precision instruments, this kind of continuous working vibration can cause interference to the equipment. One way to reduce vibration is to specially design the pump motion characteristics, such as adding a dynamic balance device to the crankshaft operation to suppress vibration. Second, the link between the pump and the equipment can be optimized, and the suspension type flexible connection method can be used to avoid the transmission of vibration to the equipment.