RAMPF dispensing systems use piston dispensing pumps and gear pumps to convey the material to be dispensed. While a cylinder with internal piston transports the material in piston dispensing pumps, gears control the conveying of material to the mixing head in gear pumps.
The external gear pump used at RAMPF consists of a housing containing two identical gears, one of which is driven. The material to be transported is conveyed in the spaces between gears and housing, and subsequently reaches the mixing head. External gear pumps are extremely accurate but rather susceptible to wear, especially in the case of coarser materials with an abrasive action. External gear pumps are able to dispense extremely small volumes with high precision.