What could be the reasons why a hydraulic diaphragm pump fails to deliver a sufficient flow rate, and how can it be resolved? Thank you!

Is it a new pump or an old one? If it’s an old pump, check whether the check valves at the inlet and outlet are in good condition, as check valves have a shorter lifespan compared to diaphragms. If it’s a new pump, could you check whether the pipes you designed have excessive pressure?

There are many reasons for this situation. 1: The pump’s stroke regulator is damaged, causing it to perform useless work. 2: The check valves at the pump inlet and outlet are not properly sealed. 3: The outlet pressure is too high, preventing the pump from delivering sufficient flow. 4: The inlet filter is clogged. 5: There is too little hydraulic oil in the pump. 6: If this pump is equipped with inlet and outlet crosslines, is the manual valve not sealing properly? 7: Clogged outlet pipeline. When a diaphragm metering pump is first started, the flow rate is not very high; the entire pipeline needs to be filled before the fluid reaches the process equipment. There is no flow for a short time, so one needs to wait a bit. As long as liquid flows out in a rhythmic manner from the pump’s outlet vent valve, it indicates that the pump is working properly. If that’s not the case, then it’s necessary to check whether the pump meets the requirements of the pipeline design.

Diaphragm pumps are positive displacement pumps, and there could be several reasons why they cannot deliver the desired volume of fluid: 1. The diaphragm is damaged； 2. Pipe blockage ； 3. The check valve is stuck and cannot return to its original position, or the seal of the check valve has failed ； 4. Diaphragm pumps generally draw in material under negative pressure; if there is air leakage in the feeding section of the diaphragm pump, it will not be able to draw in enough material.

Check the check valve seat; generally, the sealing surface of the seat should be at a right angle. A depression in it can affect flow, and because of wear, it may appear smooth and thus be mistaken for being in good condition.

1. Damage to the intake and exhaust valves； 2. Plunger packing leakage ； 3. The diaphragm or discharge pipeline is not properly sealed ； 4. Damaged diaphragm or gas not discharged from the diaphragm ； 5. Clogged filter screen ； 6. Safety valve failure ； 7. Loading adjustment failure or low oil level ； Wait

I’m not sure if the hydraulic diaphragm pump mentioned by the poster refers to the so-called diaphragm plunger pump If so, the following checks can be performed: First, check whether the hydraulic oil level is sufficient. Second, check if the pressure in the pipelines is too high, exceeding the pressure at the pump outlet ； III. Check and clean the check valves at the inlet and outlet ； Also, note that if it is an empty pipeline, it will take a long time to build up pressure; you can close the outlet valve to check whether pressure can be generated at the pump’s outlet.

There was such a post before! What the original poster is referring to is probably a metering diaphragm pump, which belongs to the positive-displacement type. Apart from the possibility that the diaphragm is not damaged, as mentioned by the poster, there are several other possible reasons for the lack of accurate measurement. 1. The valve ball and seat do not seal properly. Grind or replace. 2. The valve ball gets stuck, caused by the entry of foreign objects, etc. After knocking failed, it was disassembled for inspection. 3. The inlet filter is clogged. Turn on cleaning 4; there is air leakage in the inlet pipeline. Identify and address leakage issues. 5. The back pressure is too high. The oil refill valve does not refill oil in a timely manner. 6. Safety valve tripping, etc.