Dispensing Pumps

Dispensing Pumps

As with other liquid pumps, dispensing pumps are made up of three main parts: a cylindrical body, a pump head and a piston. Dispensing pumps typically rely on pressure created within the cylinder to move liquids from an area of high pressure to an area of low pressure. As the piston moves in and out of a cylindrical chamber, a vacuum is created which results in a buildup of pressure. The pressure forces the liquid in the cylinder to move out through the outlet valve in a specific amount. The inlet valve then releases more liquid into the cylinder to allow for the process to be repeated. In most metering systems, the piston is powered by an electric motor which enables it to achieve that linear motion. The inlet and outlet valves only allow the liquid substance to flow in the desired direction, ensuring the vacuum seal of the cylinder and preventing backflow in the pumping system.

Pumps can be fitted with either manual or automatic control systems and this operating choice will often depend on the accuracy and processing speed required by the operator. Dispensing pumps can be fitted with computers or digital pump drives that allow flow rates and mix ratios to be quickly and easily altered. They can work automatically or can alternately be activated by the push of a button or foot pedal. Using inlet and outlet valves and tubing allows a pump operator to control the substance being pumped more carefully, and further allows for the pump to be used on another product without fear of contamination. This is important in applications such as laboratory operations or food processing. Displacement dispensing pumps are particularly accurate as the amount dispensed each time is equal to the amount removed from the chamber, providing a level of high consistency in pumping. There are a number of options available and manufacturers have to decided what metering equipment is best suited to their needs. Further pump customization can be made in terms of pump speed and repetitiveness, as depending both on the substance and the receptacle, more care may need to be taken in some applications than with others.