Specifics of pipeline strength calculations for cold water pumping stations

Summary

A practical case of identifying and eliminating design faults in the piping arrangement of a second-lift pumping station in Latakia, Syria, is considered. Despite the basic design conforming to the standard solutions, misalignment of the double-entry pumps occurred during hydraulic tests. This was caused by micro-extensions of the pipelines during filling, creating torques not accounted for by the original support design. Strength verification calculations using SA 03-003-07 method and specialized software packages provided for identifying the problem and developing corrective actions: the introduction of semi-sliding bearings and elimination of vibration dampers. Implementation of these solutions ensured the reliable operation of this strategically important utility infrastructure facility.

Key words

designing , torsion torque , cold water supply pumping stations , pump misalignment , semi-sliding bearing

Method of pressure control in the water supply system

Summary

A method for pressure control in the network during the operation of pumping stations of the second elevation is proposed. The device consists of an asymmetric planetary differential connected to an eddy-current slip clutch. The method provides for maintaining the maximum efficiency and economic operation of the pump in the entire regulating range. The design of the pressure regulator in the network can be estimated by comparing the calculated efficiency value that is at least 94% for the minimum flow rates whereby the regulation is very difficult. At the optimal flow rates in the system there are no tangible losses. The synchronous electric motor is most resistant to overloads; while at the minimum flow rates it provides for the required pressure consuming the minimum amount of electricity and at the same time maintaining the rated rpm. The mechanism was implemented in models and proved the claimed parameters. The presented control scheme neither has been approbated at existing facilities, nor its technical and economic parameters have been investigated, so far. It can be used in pressure control systems of a municipal water supply system, in control systems at industrial enterprises and in individual water supply systems in private houses.

Key words

pumping station , eddy-current clutch , planetary differential , torsion torque , pressure control in a network