Q: When do you choose 2900 RPM centrifugal pumps and when do you choose 1450 RPM centrifugal pumps
A: The most commonly used pump seals are mechanical seals and packing seals.

Q: When do you choose 2900 RPM centrifugal pumps and when do you choose 1450 RPM centrifugal pumps?
A: Industrial pump most will choose 2900r.p.m pump, 1450r.p.m or lower speed pump pump body volume is relatively large, generally used for low head large flow conditions, due to the low speed of the pump, for easy wear, worry about crystalline particles are broken materials can be considered. With small flow and large head, it is recommended to use 2900r.p.m pump, after all, the investment will be much lower.

Q: Why do Attec brand centrifugal pumps need to be filled with water and vented before initial start-up?
A:, resulting in the destruction of the pump equipment. Therefore, the manual of the centrifugal pump will first indicate: no idling without liquid. To put it simply: the pump is to remove the air inside the impeller, and the centrifugal pump can work.

Q: Why is the pump with high lift easy to burn the motor with low lift, not the larger the lift, the better?
A: This problem is the most encountered in our actual customer process, the pump head selection mainly depends on the form of the pump. If it is a positive displacement type, such as piston pump, screw pump, scraper vane pump gear pump, diaphragm pump, the lift exceeds the rated value, the pressure increases, the pump load increases, and the motor is easy to burn; For speed pumps, such as centrifugal pumps, the situation is just the opposite, low head but make the pump flow is large, the load is increased, and the pump is easy to burn. Therefore, before the large centrifugal pump starts, the outlet valve should be closed, and the operation is gradually opened.

Q: Centrifugal pump uses packing seal type, how much dripping water is normal?


A: The amount of dripping water at the packing seal of the centrifugal pump is determined by the diameter of the pump shaft, and the general requirements can not drop into a linear shape, and 60 drops per minute is appropriate. However, in actual operation and use, if it is to transport clean water, the dripping water can be appropriately relaxed, and the dripping water is diverted to the sewer to prevent corrosion of the centrifugal pump suspension and bearing box.

Q: What are the advantages and disadvantages of direct coupling type and coupling type for horizontal centrifugal pump?



A:The advantages of the direct-connected horizontal centrifugal pump: the direct-connected horizontal centrifugal pump has a compact structure, a small footprint, and the concentricity of the motor shaft and the pump shaft does not need to be adjusted during installation because the motor shaft is lengthened.

Q: Whether the stainless steel pump is made of authentic 304 stainless steel, can it be determined with a magnet?







A: Whether the flow parts of the stainless steel pump are authentic 304 or 316 material, it can not be accurately determined by whether the magnet is attracted, on the contrary, the 202 series stainless steel material that is worse than 304 sometimes does not attract magnets. The most accurate and effective way is to use a spectrometer test, which can accurately and effectively see the elements and content.

Q: Can the authentic 304 stainless steel pump rust?



Answer: Can not arbitrarily say that stainless steel 304 material pump will not rust, depending on the situation. Because stainless steel material contains chromium, nickel, titanium and so on. Chromium and nickel elements have anti-rust function, which forms a protective film-blunt film to prevent stainless steel from rusting.

Under normal circumstances, as long as the film is not damaged, cracked or contaminated by impurities, stainless steel will not rust. However, if the use or maintenance is not proper, the passivation film is damaged, and the stainless steel will rust.

Q: The caliber of the pump is inches, how many millimeters does it correspond to?



A: In the actual selection, the corresponding table of the caliber of the pump is as follows:

1 inch =25 mm 1.2 inch =32mm 1.5 inch =40mm 2 inch =50mm 2.5 inch =65mm 3 inch =80mm

4 inches =100mm 5 inches =125mm 6 inches =150mm 8 inches =200mm 10 inches =250mm 12 inches =300mm

By analogy

Q: How to convert the power of the pump to kilowatts?
A: The actual power conversion table of the pump is as follows: 1HP=0.75KW

The causes and treatment of insufficient flow of pipeline centrifugal pump



1. The steering of the pipeline centrifugal pump is wrong

Solution: Adjust the motor wiring



2. Pipeline centrifugal pump speed is too low

Solution: Check the speed and increase the speed



3. The static lift of the pipeline centrifugal pump conveying system is increased

Treatment method: Check the medium height and system pressure



4. The resistance loss of pipeline centrifugal pump increases

Solution: Check the management and check valve and other obstacles



5. The wear ring of pump shell and impeller of pipeline centrifugal pump is too large

Treatment method: Replace or repair the wear ring and pipeline centrifugal pump impeller



6. Leakage of pipeline centrifugal pump

Solution: Check the shaft seal and replace it with a new one



7. The impeller of pipeline centrifugal pump is blocked, worn and corroded

Treatment: cleaning, inspection, replacement

Q: Why do VMP vertical multistage centrifugal pumps need to lift the pump shaft when installing the motor?

A: VMP vertical multistage centrifugal pump installation requires the tool to lift the whole series of rotor 2mm, tighten the bolt on the clamp coupling, complete the rigid connection between the pump shaft and the motor shaft, which is especially important for customers who only buy the pump head back to install, the result of not lifting is the pump operation is difficult, seriously cause motor burn and bottom impeller damage.

Q: What material should be used to pump seawater, 316 stainless steel, duplex stainless steel or titanium?



A: This is a problem of pump selection for many pump companies (including, of course, Aitke pump industry). According to the experience of visiting the site after pump selection for customers, it is summarized as follows:

1. Austenitic stainless steel stainless steel pump has very poor chloride ion corrosion resistance, and dual-phase stainless steel corrosion resistant pump has much better seawater corrosion resistance at room temperature than austenitic stainless steel

2. For the order bits from high to low pitting equivalent: 2507 2205 2304 317L 304L;

3. Below 20℃, even the proportion of pitting in 304L is small, but it rises sharply above 20℃; The corrosion of 2205 steel only occurs when it reaches 80 degrees and 2%Cl ion concentration. Duplex stainless steel is often used to build offshore Bridges in foreign countries.

4. For Cl ion resistance at high tem

Q: The relationship between the outlet pressure of the stainless steel pump and the pump head?

A: The new colleagues who just entered the Aitek pump industry encountered such a problem, the selection manual of stainless steel pump is generally marked with the lift of the pump, but there are often customers, especially technical engineers, who ask how much water pressure and lift of your pump, and many new colleagues do not know how to choose in this situation.

In fact, it is very simple, the outlet pressure of the stainless steel centrifugal pump or the outlet pressure is equal to the sum of the inlet pressure of the pump and the outlet head of the pump, so you remember to calculate the suction or inlet pressure of the pump when choosing the pump head, otherwise it will cause a selection error.