Today, Shanghai Shenquan wants to explain to you the knowledge content of the 6 major reasons for the low outlet pressure of centrifugal pumps, so please follow along and take a look.
ISG single-stage, single-suction vertical pipeline centrifugal pump.
1. The motor is reversed
Due to the reason of wiring, the steering of the motor will be opposite to the actual requirements of the pump, so that the steering of the pump should be observed first, if the steering is reversed, any two wires on the binding post on the motor should be exchanged.
2. The working condition point is offset to the large flow rate and low head
In general, centrifugal pumps have a continuous downward performance curve, and the flow rate gradually increases as the head decreases. In the process of operation, due to some reason, the back pressure of the pump is reduced, and the working point of the pump passively shifts with the curve of the device to the low head and large flow point, which will cause the head to decrease, in fact, this is caused by external factors such as the change of the device, and has no special relationship with the pump itself. In this case, the problem can be solved by increasing the back pressure of the pump, such as closing the point outlet valve.
3. The speed is reduced
The important factor affecting the pump head is the outer diameter of the impeller and the speed of the pump, under the condition that other conditions remain unchanged, the head of the pump is proportional to the quadratic of the speed, it can be seen that the influence of the speed on the head is very large, sometimes because of some external reasons to reduce the speed of the pump, the head of the pump will be reduced accordingly. At this time, the speed of the pump should be checked, and if the speed is not enough, the cause should be checked and solved reasonably.
4. Cavitation occurs at the inlet
If the suction inlet pressure of the pump is too low, below the saturated vapor pressure of the pumped medium, cavitation will form. At this time, it is necessary to check whether the inlet piping system is blocked or whether the opening of the inlet valve is too small, or to increase the level of the suction tank.
5. Internal leakage occurs
When the gap between the rotating part and the stationary part in the pump exceeds the design range, it will cause internal leakage, which is reflected in the drop of the discharge pressure of the pump, such as the gap between the impeller ring and the gap between multiple pumps. At this time, the corresponding disassembly and inspection should be carried out, and the parts that cause excessive clearance should be repaired or replaced.
6. The impeller flow channel is blocked
If part of the impeller's flow channel is blocked, it will affect the work of the impeller and cause the outlet pressure to drop. Therefore, it is necessary to dismantle the pump and check to remove foreign matter. To prevent the recurrence of this problem, a filter can be added before the pump inlet, if necessary.
Well, the above content is provided by Shanghai Shenquan for you, I hope it can be helpful to you.
Author: Shen Quan.
Title of this article: 6 reasons for low outlet pressure of centrifugal pumps.
Statement: Part of the article information ** on the Internet and netizens contributed, this site is only responsible for the content of the article to organize, typeset, edit, is for the purpose of transmitting more information, does not mean to agree with its views or confirm the authenticity of its content, such as this article and the transfer involves copyright and other issues, please contact the author in time, we will deal with it as soon as possible.