The pump is installed too close to the water outlet and the water outlet pipe is too short. What should I do?
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I am planning to add a new self-priming pump. The planned installation location of the pump is very close to the water outlet reservoir, which means that the water outlet pipeline is very short and far lower than the head. Remember that the actual lift should not be less than 60% of the pump's rated lift, otherwise the flow will be too large and the motor will be overloaded. Now the actual lift is less than 2 meters, while the pump's rated lift is 30 meters. In addition to closing the valve in the water outlet pipe (unprofessional operators on site can easily open the valve fully), is there any other way to limit the flow and motor load?
Add orifice plates to change the device characteristic curve.
If it is pumped into the pool, there will be no problem if it is not sealed. It is similar to the performance test platform of the water pump.； If it is sealed, it will not work. The phenomenon of stuffy pump will occur, the vibration will be large, the water temperature will rise, and the mechanical seal bearings will be easily damaged.
May I ask if you mean airtight?
1. The function of the flow-limiting orifice plate: 1. Occasions where process materials need to be depressurized. 2. When a large pressure drop is required upstream and downstream of the valve in the pipeline, in order to reduce the erosion of the valve by the fluid, when throttling through the orifice plate does not produce a gas phase, an orifice plate can be connected in series upstream of the valve. 3. Places where fluid requires small flow and continuous flow, such as pump flushing pipes, hot standby pump bypass pipes (low flow protection pipes), analytical sampling pipes, etc. 4. Where pressure reduction is required to reduce noise or wear, such as venting systems. 2. Principle of flow-limiting orifice plate: The flow-restricting orifice plate can be used as a flow measurement element to measure flow, or as a throttling element to limit flow and reduce pressure. When there is a certain pressure difference before and after the orifice plate, the fluid flows through the orifice plate. For a certain orifice diameter, the flow rate through the orifice plate increases as the pressure difference increases. But when the pressure difference exceeds a certain value (called the critical pressure difference), the flow rate of the fluid through the shrinkage hole of the orifice plate reaches the speed of sound. At this time, no matter how the pressure difference increases, as long as the pressure upstream of the orifice plate remains constant, the flow rate flowing through the orifice plate will remain at a certain value and will no longer increase. The flow-limiting orifice plate is based on this principle to limit the flow of fluid and reduce the pressure.
I have encountered such a problem. Without any restrictions, the motor often burned. Later, I changed the motor to a low-speed one and it was fine. If you don't want to change the motor, you can just add an inverter.
Changing to a low-speed motor will affect parameters such as flow rate, and the most important suction lift may have a greater impact. If an inverter is added, if the motor speed drops a lot and the heat dissipation is high, I don’t know if it can keep up.