Evaluating performance and suction limits of No.6 hand pumps with varying operational parameters

ABSTRACT Access to clean water remains a critical challenge in underdeveloped and developing regions, where suction hand pumps are a primary means of water extraction from shallow water tables. This study investigates the performance and suction limits of No.6 hand pumps under varying operational parameters, encompassing both controlled model settings and actual field conditions. Conducted in Birgunj, Nepal, an area heavily reliant on hand pumps, the research examines the influence of parameters (model/field condition, suction head, stroke speed, pipe diameter, and length) on discharge and volumetric efficiency. The findings demonstrate a significant impact of operational conditions on pump performance, with discharge and volumetric efficiency highly dependent on the tested parameters. Notably, the practical suction limit observed in field conditions (21.0 feet) is lower than in model tests (26.5 feet) for the same 1.5-inch diameter pipe, while the maximum suction limit is consistent for all cases (31.0–31.5 feet). These values represent the practical working limit and the failure point of hand pumps, providing valuable insights into their operational boundaries. The findings of this study underscore the importance of considering operational conditions for optimal hand pump performance, paving the way for enhanced water accessibility in developing countries.