Module - An assembly of PV cells framed into a weatherproof unit. See PV Array. Most solar crystalline solar panels have 36 cells, most thin film panels have 33. Piston Pump - A type of pump in which water is drawn in and forced out of a chamber by a piston mechanism. The pistons have a very short stroke, allowing the use of flexible gaskets to seal water out of the piston mechanism.
Check valves let water into and out of the chamber.
Safety Rope - Plastic rope used to suspend the pump, primarily in case of pipe breakage. May be subject to seasonal changes or lowering due to depletion. Elsewhere it is specified in millimeters. It is connected to a pump by splicing. Surface Pump - A pump that is not submersible.