| Metering pumps of DC VP and VPA type (for using in potentially explosive atmospheres) are single acting, valve, plunger pumps with one pump head assemblies. The dose adjustment is performed by length of plunger stroke changing during the machine standstill manually and metering pumps of DC VPA type allow for continuous control of number of plunger stroke changing during the machine operation either manually or automatically in dependence on the flow rate or other control variables. |  |