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In 1996 an English engineer, Frederick Philip Selwyn, patented a ‘fluid pressure amplifier’ which differed in many ways to the contemporary ram pump technology by the development of a venturi effect waste valve.

This utilises the low pressure generated by high velocity water flow around a curve-shaped elastomeric valve (with low pressure loss) to allow a valve design that enables rapid closure and with a relatively small cross sectional area and low weight. This venturi valve is configured as a ring section positioned around the supply inlet of the pump with the delivery outlet of the pump being directly in line. This allows the pump structure to be concentric and therefore inherently strong. Upon closure of the valve, it permits efficient water delivery by acting in line with the supply via a second smaller venturi effect delivery non return valve. The elastomeric material and operation of these valves also allows them to self-return without weight or spring assistance.

A pressure vessel installed on a tee connected to the delivery port of the pump provides the pulsed flow accumulation means. This unique technology and design dramatically reduced the weight, manufacturing cost and number of components required - as well as providing an overall improvement in efficiency.

Inside the Papa Ram Pump

cross section through the papa ram pump


papa ram pump section 1

Water enters the ram pump through the supply port and flows around the main valve to the exhaust port.

As the flow increases around the main valve, a differential pressure occurs causing the valve to suddenly close. The flow and mass of water is then directed through the non-return valve into the delivery port at a higher pulsed pressure.

papa ram pump section 2

This pressure suddenly reduces causing the main valve to reopen and the cycle repeats.

papa ram pump section 3

Turning the adjuster to open
the valve allows flow through
the pump to be regulated so
that a greater flow generates a
greater pressure and water delivery.

Animation of the  Pumping Cycle

gif animation of a working papa ram pump

Papa ram pump

gif video of working Papa ram pumps

Recommended Installation

This is a typical scenario where water from the source can be diverted to a catchment tank and fed to the supply tank. This provides the supply head pressure for the Papa Ram Pump to work. Water can then be pumped to a higher level, providing ‘free water’ and eliminating the need for a fueled pump or mains water

installation of papa ram pump side view
installation of papa ram pump plan view

Note: If you have a dam or weir in the watercourse it can replace the need for a catchment tank.

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