When multiple nozzles are turned on at the same time and the water pressure drops, how should a water pump be selected?

To select the appropriate pump, we first need to calculate the total flow rate requirement and the required head. For 20 nozzles, with each nozzle having a flow rate of 10 L/min, the total flow rate is: Next, the calculation of head pressure requires taking into account the height to which the water needs to be lifted as well as the pressure that needs to be achieved. A water pressure of 1 kilogram per square centimeter (approximately equal to 0.1 MPa) corresponds to a water column height of 10 meters of water (mH2O). Since the head of a water pump typically includes the vertical lift of the water and the height of the water column corresponding to the required pressure, plus 3 meters representing the distance from the pump, the total head required is: Now that we know the total flow rate is 200 L/min, the required head is 13 meters. When selecting a water pump, it is necessary to find one that meets these two conditions. Most pump manufacturers provide a performance curve showing the flow capacity of the pump at different head pressures. You also need to take into account the minor losses that may occur in practical applications. Although the problem states that pipe losses should be ignored, it is safer to leave some margin when making a choice – for example, by adding a 10%-20% performance buffer. In summary, you need a water pump that can provide at least 200 L/min of flow at a head of 13 meters, with an appropriate margin for performance. .

Hehe, the most convenient way is to find a merchant and simply state your requirements clearly, for reference.

““The vertical lift height and the height of the water column corresponding to the required pressure, plus 3 meters, which is the height of the water pump.” What does it mean by the water pump being 3 meters high? Is this 3-meter height related to the 10-meter vertical lift height mentioned earlier? If they refer to the same thing, then why not simply state that the vertical lift height is 13 meters? Thank you for the introduction

Some merchants aren’t necessarily professional either; they just choose the larger option for you

After recommending Xianze, you can work backwards using the relevant conditions to determine whether your choice is reasonable. Generally, pumps are selected within a certain range; precise control can be achieved through adjustments for reference only.

This post was last edited by Aochuang Pump Industry on 2024-5-30 09:04. There are 20 nozzles, each with a flow rate of 10 L/min; the total flow rate is therefore 200 L/min, or 12 cubic meters per hour. I’m not clear regarding the height of 3 meters for the pump – if it refers to the liquid level being three meters below the pump, then a self-priming pump or a pump equipped with a foot valve would be necessary； If it refers to the outlet being three meters above the pump, then that needs to be taken into account in the head value. When 20 nozzles are turned on at the same time, the water pressure remains stable at 1 kilogram. What is the density of the medium? Anyway, I’ll give you the algorithm first: 1 kilogram is equivalent to approximately 10 meters of water column under standard atmospheric pressure, and 10 meters/ρ gives you the head height you need – simple and straightforward. Since pipe losses are not taken into account, I won’t talk about elbows. The pump you need is one with a flow rate of 12 cubic meters per hour and a head of 10/ρ meters. Based on my experience, centrifugal pumps are the most suitable for this flow and head range. There are two options: choosing 50-32-125 with a two-pole motor is the cheapest option; the impeller can be modified according to your specific requirements. If you want it to last longer, choose 65-40-200, which is equipped with a quadrupole motor; its speed being half that of a dipole motor makes it more stable and less prone to wear. As for whether to choose a plastic pump or a metal pump, a magnetic pump or a conventional centrifugal pump, it depends on the specific operating conditions in your application. This is Anhui Aochuang Pump Industry Technology Co., Ltd. Wishing you a happy life and pleasant work!

Pump selection (assuming a closed-pump system for lifting in pressure pipelines, with water as the fluid): 1) Flow rate: 10*20*60=12 m3/h. 2) Head: 3m (vertical lift height) + 10m (pressure maintenance) + 5m (friction losses due to flow components, elbows, and other factors) = 18m H2O. 3) Efficiency: 70%. Parameters at the pump’s installation point: 12 m3/h at 25m H2O; these values can be used by the pump manufacturer for selection.

How far is it from the water pump, how many bends are there roughly, and where does the water come from?