Vibration Pumps vs. Rotary Vane/Permanent Displacement
A common myth for newcomers to the espresso
machine world is that rotary vane pumps, also known as permanent
displacement pumps, are superior to vibration pumps.
At 1st-line Equipment, LLC, we feel there are benefits and disadvantages
to both types of pumps.
Typically, vibration pumps are mostly found on tank- or reservoir-type
espresso machines. In a few small cases, they are found on espresso
machines with a direct water connection hookup. Vibration pumps
that are connected to a water line must have a solenoid valve and/or
water pressure restrictor located before the pump so as to not damage
the pump from ongoing water pressure.
Vibration pumps have the following benefits:
- Ability to draw water out of a reseroir without damage
- Lower cost for replacement
- Less susceptible to buildup of limescale causing agents (calcium
- Handle up to 40 espresso extractions every day
- Smaller size
- Built-in passive preinfusion as the pump takes 4-7 seconds to
achieve optimal extraction pressure
- Brew pressure semi-controlled by an overpressure valve (when
present in an espresso machine)
Vibration pumps have the following disadvantages:
- Noiser when refilling boiler (these pumps do go quiet to a hum
when under full pressure for extraction)
Typically, rotary vane pumps are found on espresso machines with
a direct water line connection. Just as with vibration pumps with
directer line connections, there are a few exceptions where a rotary
vane pump will be found on a tank- or reservoir-type espresso machine.
Rotary vane pumps on tank-type espresso machines run the risk of
running dry/damage in cases where the water can be extracted out
of a reservoir faster than the espresso machine can turn it off,
where the reservoir hose does not allow water to extract out of
the reservoir, or extracting water from a reservoir.
- Quieter operation when pump and motor is powered on
- Immediate ramp up brew pressure when pump is engaged
- Motor separate from pump
- Brew pressure controlled by adjusting built-in screw
Rotary vane pumps have the following disadvantages:
So, the question is why are rotary pumps used in cafes and coffee
shoppes around the word. The reason is simply volume. Rotary pumps
are determined by volume output. There are 100 and 200 liter per hour
rotary vane pumps. A rotary vane pump can extract many more espresso
per day than a vibration pump.
- Noiser when the incoming water line pressure is too low
- Longetivity diminishes when performing double duty functions
of extracting water from a reservoir and pumping water through