Analysis of the reasons for low feed volume in hydraulic diaphragm metering pumps
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Our company uses two hydraulic double-diaphragm metering pumps, with dual pump heads and dual valve assemblies. The medium transported is a formalin aqueous solution containing tiny particles of solid carbon catalyst. The two metering pumps operated continuously and stably for 15 months, but recently they started to malfunction, resulting in a decrease in the flow rate of fluid fed by the pumps. During the maintenance, the safety valve, check valve, transformer oil, etc. were replaced, and the packing gland, oil filler valve, etc. were inspected; no issues were found. I’m asking the great HaiChuan for help in analyzing what other possible causes there might be ? ?
Additional info: When the feed volume decreases, the safety valve sometimes releases oil for a while, allowing normal feeding for 2-3 hours, after which the feed volume decreases again. The reason has never been found~~
We also encountered the problem here where the hydraulic diaphragm pump couldn’t deliver the required flow rate. We disassembled it and replaced the hydraulic oil; the manufacturer recommended using Mobil XP150, but it wasn’t available on site, so we used grade 10 oil instead. Things worked normally after that replacement. I’m not sure if it was the same issue for you
Is it impossible to measure the flow upstairs, or is the feed rate gradually decreasing? ? Are you using Mobil XP150 for your hydraulic system? ? Is it still Mobil 150 that is used on the mechanical side?
Our problems aren’t exactly the same; in my case, the flow rate increases, and after 2–3 hours of operation, it decreases on its own. I’m using No. 25 transformer oil at the hydraulic side, and I replaced it with new oil as well as the safety valve yesterday. I’ll start the trial at 8 o’clock today; I’m not sure if it will solve the problem~
Check whether the inlet pipe is blocked.
There should be no problem; by using a spare one, the regular piston pump will operate normally, with no issues
Have you checked the pre-filter? ~~
The pre-filter has been checked and there are no issues~~ Someone at Haichuan said it might be a problem with the diaphragms; I plan to replace all of them soon and give it another try
Well, we can check whether the diaphragm is deformed~~ We can also check the condition of the pump head~~