Digital Computer Simulation as an Aid in Improving the Performance of Positive Displacement Pumps with Self-Acting Valves

Abstract

There is significant and growing demand for pumps with self-acting valves capable of handling water and water-based fluids. This paper describes a study performed on an eight cylinder radial piston diaphragm pump designed for water-based fluid operation. Pumping dynamics have been modelled by digital computer simulation and the results compared with those obtained from an extensive experimental programme. By means of simulation it has been possible to examine the effects of modifications to the original design. The influence of valve mass, lift, and valve seating springs on volumetric efficiency are presented. Delivery manifold pressure fluctuations are predicted using the method of characteristics taking into consideration the configuration and size of the manifold. These predictions are compared with experimental results. A modular approach has been adopted in the development of the model and as a result it may be readily adapted to suit a wide range of pumps employing self-acting valves.