Hydraulic oil is pumped under pressure to the working cylinders. The hydraulic brain block runs through a compulsory control sequence and extends one of the working cylinders, while the other one retracts at the same time.
This "boxer stroke" is transferred to the concrete pumping cylinders so that one cylinder pumps draws in concrete and the other one pumps concrete into the connected pipeline.
The switch point in the system (the concrete valve) is stroked at the same time to steer the flow of concrete. In the majority of applications, the concrete valve is the famous SCHWING Rock valve.
The SCHWING Rock valve has proven itself over many years and in countless applications to be the epitome of economy in the world of concrete valves. The Rock is robust and easy to service. It is subject to natural wear when pumping concrete and can then be rebuilt with hard-face welding. That makes it multi-economical. A real example of foresighted engineering and value for money.