The barrel-pump, is a vertical pump where it's pump-casing or pump-rotor is vertically dumped within the liquid. The rotor is mounted with the driven axe onto the pipe-shaped casing, which is conneted with its upperside to a screw-coupling. The bottom side of the tube has holes, this let's the liquid flow into the pump chamber.
Liquid barrels are available in different measures and volumes. The pump-manufacturers use the same measures and over time the measures have been standarized. When emptying smaller barrels the laboratorium barrel pump is used instead of the standard pump. This pump has been developed which is optimized for little capacity.
The barrel pump can be driven by an electromotor or by air pressure, which is placed vertically on the barrel. There are different types of motors available for the pump tubes.
For lower viscosity:
| Electro motor | Voltage | Frequency | power | Protection rate |
| Universalmotor | 220 v / 155 v | 50 Hz / 60 Hz | 290-288 Watt | IP 23 |
| Universalmotor | 42 v | 50 Hz | 440 Watt | IP 54 |
| Universalmotor | 24 v | 50 Hz | 400 Watt | IP 54 |
| AC current motor | 220 v / 380 v | 50 Hz | 0.75 - 1.1 KiloWatt | IP 54 |
Air operated barrel pump
Air use: 0.88 Nm³ / min 330 Watt
Rpm: 6900 rpm
Air pressure: 6 bar
A major disadvantage from the standard barrel pump, is the high rotation speed. The support of the drive shaft is a crucial component and has to be maintained closely. The technical lifetime of a barrel pump is notably lower than a horizontal centrifugal pump, which are constructed with motors that can handle 1450 or 2900 rpm. Because of the low rpm the pump produces relatively little noise, compared to the faster barrel pump.
Sometimes the pump is constructed with a mechanical seal. This depends on what liquid is used.
When the liquid crystallize or harden or which are sticky a mechanical seal is used. For all
other applications the sealles type drum pump is used, since it cannot fail when running dry.