PVC pipe expansion and deformation
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I have a hydrochloric acid tank with a self-priming pump connected to it, 2.2kw. This self-priming pump has two functions. One is to pump external incoming materials into the tank, and the other is to pump the contents in the tank to the workshop cache tank. Use manual valve to switch. I added an electromagnetic flowmeter in the middle of the pipe flowing into the workshop, using DN40 PVC pipe. The on-site operation is that after the workers use up the buffer tank in the workshop, they will manually turn on the self-priming pump to extract hydrochloric acid. This process takes about 5 minutes. I observed that the moment it was turned on, the impact of the self-priming pump was quite large. 1/After using it for a period of time, the PVC pipe expanded and deformed, connecting the joint of the self-priming pump. But I'm not sure what's causing this, is it a matter of momentary pressure? 2/ It seems that the electromagnetic flowmeter is not accurate, especially when the flow rate changes greatly, even if the pipe is full, the error is quite large. In the end only the volumetric flow rate can be calculated. I would like to ask, regarding chemical raw materials such as hydrochloric acid, formaldehyde or acids and alkalis, if you want to measure the usage more accurately, can you use a flow meter? Or under what circumstances the flow meter will have the smallest error and the most stability.
It looks very dangerous. The pressure-bearing strength of the pipeline is not enough. The electromagnetic flowmeter has certain installation requirements. It is best to try it strictly in accordance with the installation requirements!
Brother, what you focus on is that the flow meter is not a problem and there is no problem with the installation. It must be caused by unreasonable pipeline design or other reasons.
Is it possible that the wall thickness of the pipe is not enough to bear the pressure? I feel like it needs to be checked. The riser is already bent, so it is recommended to make a limit. The use of a flowmeter requires a certain straight section before and after the measuring device. Generally, when in doubt, the length of the front and rear straight sections can be no less than 20 times and 6 times the inner diameter of the pipe respectively.
1. Confirm whether the hydrochloric acid contains other impurities, such as solvents, which will cause the PVC pipe to swell. 2. Whether the pipe is a thickened chemical pipe. 3. It can also be replaced with a polypropylene pipe.
You are obviously using a Lesso 1.0mpa tube, which is not suitable for use as a dosing tube. The minimum requirement for a dosing tube is 1.6mpa. Generally, no matter how low the cost, you have to use Nanya.
It shouldn't be a problem with the material of the pipe. It has been used without problems for many years. Our initial suspicion is that the worker turned on the pump, but the manual valve for pipe switching was not opened, causing idling. The question is why does it heat and expand when idling?
What is the concept of water hammer? We suspect that the workers turned on the pump, but the manual valve for switching the pipeline was not opened, so this phenomenon was caused. Is this right?
Is there still this requirement? I really didn’t know that the minimum requirement for dosing is 1.6mpa. But the problem is that there shouldn't be that much pressure inside.