The self-priming centrifugal pump is ready to be replaced. Which centrifugal pump manufacturers have better quality?
Thread Content
There are two sewage pumps in our factory, which are self-priming centrifugal pumps. They have been used for about 2 years. Since they were put into use, the two sewage pumps have experienced severe vibration and malfunction. The pump shafts, bearings, and mechanical seals have been replaced many times (there is cavitation on the impeller surface of one pump). After installation and alignment, the vibration is still large. We think it is a problem with the machine pump, and we want to replace these two self-priming centrifugal pumps. Are there any domestic manufacturers of self-priming centrifugal pumps with good quality? sewage pump: 65ZWPW-30-40 7.5Kw, 2900r/min head: 40m, flow rate 30m3/L sewage lift pump: 50CYZ-A-75 11Kw, 2930r/min, lift: 75m, flow rate 20m3/L
First check whether the working conditions, flow rate and head are working in the high efficiency zone. If there are no problems, consider replacing the pump. Sewage pumps also need to consider the pump medium. Domestic sewage pumps are strong in Shijiazhuang and Liancheng in Shanghai. For reference
Self-priming pumps have higher requirements on pump cavitation margin due to the requirement of suction height. Do the two pumps in this working condition meet the on-site self-priming height? Insufficient self-priming height will cause pump cavitation vibration due to long-term cavitation state operation of the pump.
Shenyang Corrosion Resistant has focused on self-priming pumps for many years
The actual flow rate of the sewage pump cannot be known because there is no flow meter, and the suction height is not indicated on the nameplate.
Let’s analyze the reasons for large vibration and corrosion of sewage pumps
Is the steel support between the base and the foundation of this pump not high enough when you installed it? It may cause resonance. From the vibration measurement data, it seems that the motor has more factors. Is there any mechanical expert to study it? When choosing a pump, I personally recommend using a corrosion-resistant and wear-resistant pump, and find a company that makes chemical pumps.
This steel support was added by the builder himself. I was not on site at the time and I don’t know the specific construction process.
It looks like the base was installed to match the pipe elevation. The vibration is largest in the vertical direction, indicating that the stiffness in the vertical direction is insufficient. You can measure the basic vibration and analyze it. We have four pumps with a similar situation, reflecting large vertical vibrations. However, the leaders have never heard of the concept of stiffness and ignore it. Let’s take a look at Wang Shaofeng and Mr. Wang’s WeChat public account mirook to chat about vibration.
It is obvious that the vibration of the motor exceeds the standard. Strengthen the fixation. The impeller is caused by cavitation.
This pump does not give a specific NPSH, which is an important parameter. In addition, regarding the foundation support issue, you can measure the foundation vibration value as a reference. It is not clear from the picture whether the bottom of the base is fully welded, so reinforcement can be considered. The stainless steel impeller can be replaced according to the corrosiveness of the sewage. The self-priming pump manufacturer Shijiazhuang is really good. Many manufacturers currently offer a solution of centrifugal pump + self-priming machine, which is also very reliable.