Metering Pump

A metering pump moves a precise amount of liquid during a specified time period yielding an accurate volumetric flow. Metering pumps are used to pump chemicals, solutions, etc- There are a range of different metering pump technologies, and generally the application drives the pump selection. Critical application criteria include the viscosity, temperature, discharge pressure, required flow rate, and compatible wetted path materials. Most metering pumps have a pump head and a motor with some adjustment mechanism either manual or electronic depending on the pump manufacturer.

Piston Pumps

Many metering pumps are piston driven. A piston driven pump is a positive displacement method where the piston displaces the fluid in the reservoir chamber. The stroke and internal volume of the pumpingchamber determine the dispense amount and flow rate. Often piston pumps have two check valves on the inlet and outlet. As the piston recedes in the pumping chamber a negative pressure or vacuum is generated which opens the inlet check valve and pulls fluid towards the pumping chamber. Once fluid has filled the reservoir and the pump begins the discharge stroke, the piston pushes the fluid out of the fluid chamber through the outlet and through the outlet check valve. Instrument Pump Inc.`s positive displacement piston pump uses a valveless rotating, reciprocating precision Ceramic Piston. Located on the piston is a flat which act as a valve. The benefit of a valveless piston pump is there are no valves to clog. A valveless piston pump is ideal for applications with high viscosities as well as fluids with particulate or colloidal systems

Advantages of metering with a valveless piston pump

Compared with other metering pump technologies, valveless positive displacement metering pumps have a few key advantages:

• Long life span
• Pressure range up to 200 psi
• Independent flow rate at varying pressures
• High accuracy <0.5%
• High repeatability
• High precision
• Wide range of applications including high viscosities up to 250,000 cps.
• Valveless action enables pass through of particulate and solids
• Ceramic internals are chemically resistant to a wide range of corrosive materials
• One moving part