Piston metering systems

DOPAG piston pump metering and mixing systems feature a modular and customer-specific design. Therefore, different basic configurations are available with regard to the intended application and the requirements.

Basically, a distinction can be made between this group of dosing pumps according to their mode of action. Here the so-called "single-acting piston pump" or also called shot pump as well as the "double-acting piston pump", which is also called differential piston pump, are used.

• With the shot pump, the functions are different in both strokes. The medium is sucked in one stroke and discharged in the other. This conveying process is achieved by the use of automatic (non-return) or controlled valves in the material flow.
• The differential piston pump is characterised by a combination of two pistons of different diameters connected in series and mechanically fixed to each other. The lower piston sucks in the larger volume in the upward stroke, while at the same time the upper (smaller) delivery chamber is emptied in the delivery direction. In the downward stroke, the lower (larger) dosing chamber is pressed out in the conveying direction and the upper (smaller) conveying chamber is filled simultaneously with this larger volume flow. If the ratio of the upper to lower conveying chamber is adjusted accordingly, a continuous material flow can be created.