Assembly Notes:
Pressure Chamber - A bicycle or "scooter tire" inner tube is placed inside the pressure chamber (part 15) as an "air bladder" to prevent water-logging or air-logging. Inflate the tube until it is "spongy" when squeezed, then insert it in the chamber. It should not be inflated very tightly, but have some "give" to it. Note that water will absorb air over time, so the inner tube is used to help prevent much of this absorbtion. You may find it necessary, however, to drain the ram pump occasionally to allow more air into the chamber. (The University of Warwick design (link below, pages 12-13) suggests the use of a "snifter" to allow air to be re-introduced to the ram during operation. Their design, however, is substantially different from the one offered here and provides a location (the branch of a tee) where the addition of a snifter is logical. This design does not. Also, correctly sizing the snifter valve (or hole as the case may be) can be problematical and may allow the addition of too much air, resulting in air in the drive pipe and ceasing of pumping operation. For these reasons we have elected not to include one in this design.)