The new piston diaphragm pumps of the series R510.1 and 511.1 (photo) deliver flowrates of 65 to 1,900 L/h at pressures up to 220 bar. The pumps are qualified for a wide range of applications, including the petrochemical industry. The stroke mechanism of the pumps has been designed as variable eccentric drives, which provides a number of benefits, including: it enables a linear and precise stroke-length setting, thus enabling precise metering even with high flowrates and high pressure; the harmonic movement sequence — even for partial stroke operation — produces significantly less pulsation than other metering pumps; and the stroke can be adjusted from 0 to 100% using a hand wheel or actuator. The pumps are available for explosion-protected areas and are in accordance with API Standard 675. — Seybert & Rahier (SERA) GmbH + Co. KG, Immenhausen, Germany