How Does It Work?
All HEYPAC pumps are driven by compressed air or other inert gases. The compressed
air is applied to either side of an air drive piston which is connected via a piston
rod to a smaller diameter fluid piston. The ratio between the diameter of the air
drive piston and the diameter of the fluid piston gives the pumps intensification
ratio. The diameter of the air drive piston remains the same across a pump series
while the fluid piston diameter varies from model to model to give a range of intensification
ratios.
Pump up and down positions: click to enlarge
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The reciprocating action of the pump is controlled by an internal system of air
valves and pilot valves and is completely pneumatic requiring no mechanically actuated
valves to function. The pump will begin to cycle automatically whenever a demand
is placed on the system or the air pressure is increased and will cycle until the
forces on the fluid side equal the forces on the air drive side at which point the
pump will stall out and maintain pressure with zero energy consumption. The pump
will remain in the stalled condition until either the air pressure is increased
or a demand is placed on the fluid side at which point the system balance will be
lost and the pump will start to reciprocate again until it reaches the balanced
condition again and stalls out. Flow rates from the pumps are highest at low pressure,
diminishing as the pressure increases, with a corresponding reduction in pump speed
as it approaches the pressure balance/ stall condition.
The majority of HEYPAC pumps are of a double acting nature, delivering flow on both
the up and down stroke of the pump mechanism via an internal system of suction and
transfer valves.