How to control the outlet pressure of a screw pump?
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I want to adjust the outlet pressure of the screw pump. How do I do that? If the pressure increases, can the pump outlet valve be closed? I’m asking for everyone’s help, thank you!
Like other positive displacement pumps, when the discharge outlet of a screw pump is completely closed, the pressure inside the pump rises to a level that can damage the pump or overload the motor. Therefore, the maximum pressure it can actually achieve depends on its mechanical strength. What is the landlord’s goal in increasing work pressure – to boost traffic? If that is the goal, speed needs to be taken into consideration.
A screw pump is a type of positive displacement pump; its outlet pressure depends entirely on the back pressure, and it cannot be adjusted through the outlet valve. If you want to adjust the flow rate (reduce the discharge flow), there are generally two methods: 1. Open the return valve. A portion of the medium is returned through a bypass. 2. Adjust the speed. Pump flow is related to rotational speed.
We often use a return valve for adjustment; it is not possible to use an outlet valve for this purpose, as that would cause the pump’s safety valve to activate and increase the pressure. By reducing the setting of the return valve, the pressure can be lowered, and vice versa
If it’s really not possible to make adjustments, then a return line can be added at the outlet to regulate the outlet pressure; the lubrication oil pumps in large-scale equipment are usually screw pumps, and they are controlled in this manner.
1. Bypass adjustment 2. Speed adjustment
The best approach is to use a frequency converter for the motor, and a pressure-controlled check valve at the outlet to set the outlet pressure and enable automatic adjustment; when the pressure is high, the check valve opens and the current decreases. It can also protect the motor.
The outlet pressure of a screw pump can be adjusted using a frequency converter, or it can also be done through a return valve. But under no circumstances should it be done by controlling the outlet valve. Remember
The flow and pressure regulation of positive displacement pumps is mainly achieved through two methods: frequency conversion to adjust the speed, and outlet bypass throttling!
Great material! Please share more of it
The outlet pressure of a screw pump (positive displacement pump) is automatically regulated, that is, it can automatically adapt to the pipeline system within its operating pressure range. Why is it necessary to adjust the outlet pressure? What generally needs to be adjusted is the flow rate, and the backflow method can be used.
The answer on the 3rd floor is the most accurate one; please do not be misled by incorrect answers!
Personally, I think there’s no problem with making adjustments within the specified range; it certainly won’t work if the settings exceed the required limits. I hope the experts at Haiyou can provide the final correct answer. :handshake
After backflow occurs, the flow rate in the pipeline decreases, the pressure drop reduces, and as a result the output pressure of the pump drops, thereby serving to regulate the pressure.