In applications for lowering groundwater, piston pumps have served as reliable pumping units for many years. In the 1970s, the piston pump was increasingly replaced by modern vacuum units. The main reason for this was the demand for greater pumping capacity. In practice, the vacuum of piston pumps is limited to a suction height of 7 m water column and the actual volume flows do not exceed 90 m³/h per unit (air flow rate, water flow rate or a mixture of both). Of course, several units can increase the total pumping capacity, but this is associated with higher equipment usage and thus higher costs. Demands are placed on the quality of the pumped groundwater. Sand in the water causes premature wear and can lead to the premature failure of the unit and thus to unforeseeable consequential damage. Nevertheless, there are niche applications for piston pumps. These can be found, for example, in so-called line construction sites (pipeline construction).
The HC 272 is designed for tough construction site use. An external galvanized steel frame with an integrated tray provides very good protection against external mechanical damage and also protects against liquid leakage. The units are stackable and the solid supporting structure allows a secure pick-up by a load hook. The engine with the large oil pan in combination with the sufficiently dimensioned fuel tank allows 24/7 operation at full load. The piston pump is lubricated automatically. Long service lives are achieved by oversized bearings and low piston speeds. The piston pump has an integrated air vessel. This pressure compensation protects the hoses, for example, if the distance to the receiving water is longer. The pulsation of the discharge hoses is practically eliminated.
