Some have run without stopping for ten years or more in systems supplied with clean water from a reservoir. Failures in ram pumpsystems often occur outside the pump itself - blockage of dilter screens, damage to pipes, sedimentation of pipes and tanks etc. Poorly located drive pipes sometimes show perforationdue to a process called cavitation. Pumps made in local workshops are less durable than some of the imported machines made of cast iron, but their lower price usually makes them better value than either imported ram pumps or other pumps of comparable throughput. They also have the advantage of being locally repairable with ready access to spare parts.
Ram pumps run unattended for long periods, so running faults can go unattended for days or weeks.
This can lead to expensive failures. The historical high reliability of ram pumps may reflect in part the social circumstances of their traditional use on large farms or mission stations where regular checks are made. The routine supervision of village systems may be much poorer and great care should be taken to ensure adequate caretaking. Any particular ram pump is normally capable of running under quite a wide range of conditions. In situationswhere the water source has a larger flow than that required, each pump can be tuned to use as much drive water as possible to ensure minimun capital costs.