METERING PUMP TECHNOLOGY Posiload Piston Metering Pump |  Posiload Rod Metering Pump Gear Pump |  Double Ball Check Pump Posiload Piston Metering Pump The piston is fully retracted and material enters the metering tube through the pump inlet. The piston advances to the entrance of the metering tube and closes it off, acting as an inlet non-return valve. As the piston travels through the metering tube, the outlet non-return valve opens and material is accurately displaced. The length of metering stroke is adjustable. To reload the pump, the piston quickly withdraws from the metering tube closing the outlet non-return valve, and creating a vacuum to assist material loading. Posiload Rod Metering Pump The metering rod is fully retracted and material enters the metering tube through the pump inlet. The metering rod advances to the seal at the entrance of the metering tube and closes it off, acting as an inlet non-return valve. As the metering rod travels through the metering tube, the outlet non-return valve opens and material is accurately displaced. The length of metering stroke is adjustable. To reload the pump, the metering rod quickly withdraws from the metering tube, closing the outlet non-return valve, and creating a vacuum to assist material loading. Rod Positive Displacement Metering To load the valve, the metering rod is retracted to a precisely set position determining the volume of each material. The outlet ports are blocked and material feed inlets are opened. Materials are transferred into the metering chamber by a pressurized feed system. During the dispense delay, the balanced spool assemblies shift. The material inlets are blocked and the outlet ports are opened. The metering rod remains in the retracted position. Dispensing begins when the metering rod is driven down. "A" and "B" materials are simultaneously dispensed from the metering chamber into the disposable mixer.  Each component is dispensed at the predetermined ratio. Gear Pump Material is drawn into the pump inlet to be metered by the gear teeth around the inside circumference of the pump. The gear teeth carry the material through the pump with the accuracy of volumetric displacement subject to how close tolerance is maintained between the teeth and the inside walls of the pump. Metered material is discharged through the pump outlet. Both the size of the pump and the rotational speed determine the volume to be discharged subject to any slippage within the pump. Double Ball Check Pump Figure A This type of pump utilizes two ball checks to produce double-acting pumping action to dispense on both the down and up stroke. At the top of the stroke, the piston rod is ready to move down and both the upper and lower ball checks are momentarily closed. Figure B As the piston rod pushes the piston down through the pump tube, the lower ball check remains closed preventing material flow out the pump inlet. The material in the lower chamber lifts the upper ball check from its seat and material flows into the upper chamber. Since the upper chamber has less volume (approximately one-half) than the lower chamber due to the displacement of the piston rod, material is forced through the pump outlet. Figure C At the bottom of the stroke, the piston rod is ready to move up and both the upper and lower ball checks again are momentarily closed. Figure D As the piston rod pulls the piston up through the pump tube, the upper ball check remains closed preventing material flow from the lower chamber into the upper chamber. A vacuum draws the lower ball check off its seat and material flows through the pump inlet into the lower chamber. At the same time, material in the upper chamber is forced out the pump outlet as new material is drawn into the pump inlet.   Applications |  Products |  About Us |  Contact Us |  Request Information