How to match the flow rate, head, and speed of a corrosion-resistant and wear-resistant multi-stage pump

Category: Water pump knowledge

2025-04-18

There is a close relationship between the flow rate, speed, and head of a corrosion-resistant and wear-resistant multi-stage pump. Reasonable matching can ensure its effective and stable operation. Generally speaking, it can be matched based on the theoretical relationship between the three and empirical formulas according to actual operating conditions.

1. Relationship between flow rate and speed

Under other unchanged conditions, the flow rate of a multi-stage pump is approximately proportional to the speed, following the law of similarity. The formula is Q1/Q2 = n1/n2, where Q1 and Q2 are the flow rates at different speeds, and n1 and n2 are the corresponding speeds. For example, when the speed is doubled, the flow rate will also increase accordingly, provided that the pump structure and operating conditions permit. However, increasing the speed may lead to changes in the flow state of the fluid in the pump, such as cavitation, so comprehensive consideration is needed.

2. Relationship between head and speed

The head is proportional to the square of the speed, and the formula is H1/H2 = (n1/n2)2, where H1 and H2 are the heads at different speeds. When the speed increases, the work done by the impeller on the fluid increases, causing the head to rise, but it will also increase the mechanical load and energy consumption of the pump. Therefore, the speed should be reasonably selected under the premise of meeting the actual needs to avoid unnecessary energy waste and equipment wear and tear.

3. Matching method of the three

Clarify operating conditions: First, determine the required flow rate and head in the actual application scenario. For example, in a high-rise building water supply system, the required head and flow rate need to be calculated based on factors such as building height, number of water points, and water demand.

Select a suitable pump type: According to the determined flow rate and head requirements, refer to the pump performance curve to select a multi-stage pump model that meets the operating conditions. The performance curve shows the relationship between the flow rate, head, and efficiency of the pump at different speeds, which is an important basis for selecting the pump type.

Adjust the speed: If the flow rate and head of the existing pump cannot fully meet the requirements, the speed can be adjusted for optimization. However, it should be noted that the adjustment range of the speed should be within the design allowable range of the pump, otherwise it may affect the normal operation and service life of the pump. At the same time, after adjusting the speed, the efficiency and energy consumption of the pump need to be re-evaluated.

In practical applications, it is also necessary to consider the influence of factors such as pipe resistance and fluid properties on the operation of the multi-stage pump, and through continuous debugging and optimization, achieve a good match between flow rate, speed, and head.

Previous: How to use corrosion-resistant and wear-resistant multi-stage pumps

Next: Factors affecting the cavitation margin of corrosion-resistant and wear-resistant multi-stage pumps and solutions

Contact Us

Free Hotline:0086-13307481676

Fixed telephone:0086-13307481676      

Mobile:0086-13307481676(WeChat)

E-mail:sales@sanchangpump.com