Vibration Pumps vs. Rotary Vane/Permanent Displacement Pumps

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.

Vibration 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 and magnesium)
• 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:

• 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 coffee grinds