Relationship between pump head and inlet and outlet water

The power of the pump is directly proportional to the flow, while the flow is inversely proportional to the lift. When the lift increases, the flow decreases and the power decreases; On the contrary, if the lift decreases, the flow will increase and the power will increase.

Therefore, if the high-lift pump is used in low-lift for a long time (less than 60% of the calibrated value and not less than 80% recommended by some codes), the motor will be overloaded due to excessive flow, which will lead to overheating or even burning.

Actual lift of water pump = total lift loss lift. When the pump model is determined, the total lift is fixed, and the lost lift is mainly determined by the pipeline resistance. The smaller the pipe diameter, the greater the friction resistance, which leads to the increase of lost lift, but the actual lift decreases and the efficiency decreases (such as small pipe diameter with large pump).

When the small-diameter pump uses large water pipes, the pipeline resistance decreases, the loss head decreases, the actual head increases, the flow increases slightly, but the increase of power consumption is controllable. Within the rated lift range, large pipe diameter can reduce pipeline loss.

Users often mistakenly believe that increasing pipe diameter will lead to motor overload due to increasing water pressure. In fact, the liquid pressure is only related to the head and has nothing to do with the pipe diameter. As long as the head is constant, the impeller bears the same pressure, and the change of pipe diameter only affects the flow and resistance.

Therefore, in engineering application, it is necessary to avoid "lifting the lift" by reducing the pipe diameter, which will reduce the actual lift and efficiency. It is necessary to reasonably match the pipe diameter and pump parameters, and give priority to selecting the pipe diameter according to the design specification. Large-diameter system can reduce energy consumption loss, but it is necessary to calculate the flow rate and motor carrying capacity.

Pump selection needs to integrate parameters such as head, flow rate and pipe diameter to avoid the risk of system inefficiency or overload caused by misjudgment of a single parameter. However, traditional selection methods often rely on manual experience and static parameter calculation, and it is difficult to capture the dynamic changes under complex working conditions in real time.

As a pioneer in intelligent industrial pumps, SEAD leverages IoT, big data, and AI technologies to bridge the physical worlds of products, users, and enterprises. This endows traditional industrial pumps with smart sensing, remote control, and intelligent maintenance capabilities.

Its sensing function endows the product with life, which can make users, vendors and factories feel the working conditions of the product, and fundamentally solve the risks of inefficient and overload in product selection errors and irregular use. Ensure that the product always works under the best working conditions, so as to reduce the failure rate and prolong the product life.

SEAD Digital Smart Industrial Pump covers a wide range of centrifugal pumps, pipeline pumps, sewage pumps, middle-opening pumps, fire pumps, single-stage double-suction centrifugal pumps, end-suction centrifugal pumps and other categories.

It provides long-term reliable guarantee for industrial water treatment, district heating, HVAC, construction, municipal water supply and drainage, energy, metallurgy, environmental protection, food cleaning, petrochemical and other applications, marking the paradigm shift of industrial pumps from mechanical drive to data drive.

Turkey International Industrial Fair

From May 28th to 31st, 2025, SEAD PUMP will make a stunning appearance at WIN EURASIA 2025 with its wear-resistant sealed intelligent water pumps featuring patented sealing structures. You are warmly welcome to visit our booth, Booth No. [8G500]. Here, you will witness the innovative achievements of the water pump industry and experience the charm of cutting-edge technology.