Problems with metering pump flow rate
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At the same stroke, the dosing volume of the two pumps differs by more than a factor of two. There is no problem with the diaphragm oil and the diaphragm of the pump. May I ask the experts what caused this situation?
Check the check valves for import and export to see if there are any issues with their sealing.
If the operating conditions of the two pumps are the same, pay special attention to the inlet and outlet valves as well as the check valves.
All the opinions above are correct~~~~ There is a high probability of internal leakage in the seal between the seat and the ball of the one-way valve at the entrance/exit.
With two pumps and one tank, the liquid level drops over 12 hours for one pump and 6 hours for the other; could it be that the check valve of the pump that takes 12 hours to cause such a drop has worn out and is leaking?
Let’s take a close look at the check valves on the inlet and outlet of the metering pump! The check valves in such pumps are very small; even a slight amount of dirt or impurities, or poor manufacturing precision of the check valves themselves, can prevent the pump from delivering fluid properly! In our department, there was a problem with the flocculant pump in one desulfurization and denitration unit; the maintenance staff tried to resolve it for over a week without success. When the manufacturer from Benxi (I won’t mention the full name – those who are familiar with the company will know right away which one it is) arrived, they found that there was some roughness between the valve seat inside the outlet check valve and the valve ball. After filing those areas, the pump started working properly again! Damn it! ! ! !
Check the one that has less leakage. Examine the check valve, that is, to see if the valve ball and the valve seat are sealing properly. If the liquid cannot be sealed off, you can use grinding paste to polish the sealing surfaces.
If all the equipment related to the pump is in good condition, it might be worth checking whether there is any blockage in the outlet pipeline. The metering pump in my company once became clogged due to the operator adding the wrong fluid. . . . .
In addition to checking the check valves at the inlet and outlet, it is also necessary to verify whether the O-rings on the plunger are worn