Petrol drive diaphragm

Self priming diaphragm pumps



Self-priming diaphragm pumps

Ideal for pumping thick, muddy, abrasive liquids with solids in suspension.
Often used for smaller wellpointing applications such as installing small pump chambers, where a vacuum prime centrifugal pump is too large.

The system consists of a diaphragm guided by a coupling rod. The flow generated by the movement of the diaphragm is controlled by check valves at the suction and delivery.

As the diaphragm rises away from the bottom of the casing it produces a vacuum which draws the liquid into the casing through the suction valve. When the diaphragm is on the downstroke, the liquid is expelled through the delivery valve.



Product Information

Overview Inside the pump

Caffini Diaphragm Pump - Honda engine

  • Rapid dry self-priming down to 6 m in a few seconds
  • Can run dry indefinitely
  • High abrasion resistance
  • Large size solids handling
  • Capacity is proportional to speed
  • Simple construction: the parts subject to wear or aging, such as diaphragms and valves, are easily replaceable
  • Aluminium or cast iron construction available


ModelSolids (mm)Max Head (m)Max Flow (l/min)Engine
Caffini Lib 1-35015330Honda GX160
Caffini Lib 1-46015500Honda GX270
Caffini Lib 2-66015800Honda GX390
Overview Inside the pump
Caffini diaphragms


Diaphragms made from
several different rubber
materials depending on your
application. Allows the
pump to pass large solids.

Caffini Simple Design

Simple design

No rotating part or seal in
contact with the liquid.

Caffini Helical Gears

Helical Gears

Helical cut gears reduces
noise and gear chatter during

Caffini Valves


Heavy rubber check valves
on suction and discharge

Caffini Suction Chamber

Suction Chamber

Chamber on the suction side
of the pump helps to reduce
surges in the flow


Caffini Drive Rod

Drive Rod

Caffini models have either
a sprung loaded or rigid
drive rod.

Caffini Spares

Spare Parts

Only a few spare parts
needed to keep these pumps
running! Very simple and
occasional maintenance

Caffini Construction


Cast iron, aluminium,
stainless steel or bronze
construction for wetted