Laboratory Testing of Hand - Operated Water Pumps
A program was undertaken to subject the durability and reliability of A.I.D.-designed hand pumps to laboratory testing. This report presents results and conclusions from tests of 15 pumps made in Tunisia, Ecuador, the Dominican Republic, Honduras, the Philippines, and Haiti, the United States and the United Kingdom (the Moyno and Mono rotary hand pumps), and Malawi (reciprocating hand pumps), as well as of three types of foot valves. All pumps except those from Haiti appeared suitable for field use with minor design changes, assuming the availability of foundry technical assistance, tight quality control, and responsible maintenance (lubrication, minor part replacement). The Malawi hand pumps were found to be of good quality, as were the rotary pumps, although additional testing was recommended for the latter. A brass foot valve from the Dominican Republic performed well, but one made of plastic did not. The tests revealed that a leather foot valve, while inexpensive, is less durable than metal designs, and that threaded connections should be minimized as much as possible. The quality of castings and machining, and of the hardening process for pins and bushings, varied widely. A Honduran shallow well pump with properly hardened pins and bushings showed negligible wear after 6 million cycles without lubrication. It is recommended to consider using sealed bearings in the A.I.D. cast iron pump in order to eliminate the need for lubrication, and to specify steel for the pump body in order to provide for uniform material, simple fabrication, and reduced maintenance.