These pumps are noted for a metering accuracy that is independent of back pressure. Boasts of a flow rate that is linear to the variation in stroke length. The diaphragm is very durable because it is balanced by the liquid to be dosed and the pressure exerted by hydraulic oil. The excellent metering accuracy is due to the automatic air bleeding from the hydraulic oil. The built-in pressure valve provides sufficient protection from over-pressure. Rupture Indication Arrangement (RIA), an innovative device that senses rupture in diagram is integrated in the pump. Whenever these pumps are to be used in hazardous areas, then it is possible to place the liquid head at a distance away from the drive side. Hydraulic oil in a flexible tube couples both the head and the drive.