A project has been given to me at work, with no schematics or idea of where it was going. I need to fill 5 30ml bottles at a time with a food-grade liquid.

Based on the parts I have, I think the design was going to use a air agitated pressure pot tank which is used for spraying paint, which would work if we weren't using food grade liquid, so right off the bat I cant use that.

The main parts that I can use are an Allen Bradley micrologix plc, 2 pneumatic cylinders, a couple solenoids, start and stop buttons.

My question is: to fill a 30ml bottle with this liquid, would a positive displacement pump with a vfd be the best way of slowing the pdp down enough to fill the 5 30ml bottle at a time?

I do have a little experience with this particular plc so the ladder logic is not the issue, its the figuring out the specs for the pump and the motor. Any input would be very helpful also any links would be great. At this point im trying to determine if this is a huge waste of time and money or should I just go buy a filling machine for $3-5000.


A specific type of equipment is named 'metering pump' (chemical dosing pump) which can be controlled by PLC, computer, serial link or on-off switch, etc. These are standard equipment as used in lab., hospital for patient, chemical process control for PCB factory and food-processing factories.

'Metered' refers to precise control of either or both (one-shot) volume and (continuous) flow-rate, depending on specific mechanical configuration and working principle.

search google will give hundreds of units, from many brands, functions, size, and price. Try look for lab type unit for your 30ml requirement (there are big unit for hundred of litres as in food industry). There are specific types for food, 'harsh chemical (PCB etch)' and even living human/animal blood/fluids.


As original poster questioned price, one may google and get prices listed on some seller's site at much lower cost than original poster's mentioning.

Hope it helps


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