Metering Pump in Conjuction with Booster pump

[brs11]

We have to transfer a very viscous liquid through the metering gear pump. Can we use a gear pump with positive displacement as a booster pump installed before this meterimg pump?

 

[jistre]

Hmm...

I don't think two PD pumps in tandem are a very good idea. Let's say that the booster pump delivers 1.01 gpm and the metering pump delivers 1.00 gpm. Then, that extra 0.01 gpm will likely try to collect between the two pumps. At some point, you'll likely overpressure and either open a protection device or break something.

On the other hand, if the booster pump only delivers 0.99 gpm and the metering pump is delivering 1.00 gpm, then whatever overhead volume exists between the two pumps will be slowly drained down until the only thing in the line is the 0.99 gpm that the booster pump can deliver. Then, at the very least, your metering pump will be unable to deliver the flow rate simply because it's being fed less than the needed flow rate.

If one of the pumps isn't PD, then this is all useless.

 

[Compositepro]

A booster pump is just that - a pressure booster. It can be any type that has a pressure controlled output. Air-driven reciprocating with air pressure control will work. So will a gear pump with a recirculation line and relief valve. These are "positive displacement" pumps but you are not using that feature so it isn't really relevant.