Positive metering pumps offers hd series hydraulically actuated diaphragm pumps, which are available in different models. These pumps have capacity up to 7000 pressure up to 100 kg/cm2. The capacity can be varied from 0 to the maximum. Metering accuracy is almost independent pressure. Flow rate is linear to stroke length variation. Diaphragm is always balanced between the pressure exerted by the hydraulic oil and the liquid to be dosed. Longer diaphragm life automatic air bleeding from the hydraulic oil ensures better, metering accuracy arrangement of in-built pressure relief valve to protect the pumps from pressure exceeding the rated pressure. Rupture indication arrangement [ria] is an additional facility available with these pumps. These pumps with ria are provided with a sandwich of two diaphragms. The rupture of anyone of the diaphragms can be sensed by pressure sensing device. In case of metering pumps to be used in hazardous areas the liquid head can be kept at a remote place from the drive side. The head and drive are coupled by hydraulic oil in a flexible tube.
