Very often, a 55 gallon (45.8 liter) barrel, or drum, is used to transport and store liquid products. These barrels can be quite heavy and are somewhat bulky. In order to easily get the product out of the barrel, a barrel pump is used.
Generally, a barrel pump consists of a long tube or hose, able to reach to the bottom of the barrel, the pump housing on top, and another hose leading from the pump housing to a separate container. The pump housing encompasses the pump motor, or crank, as well as the impellers and gearing that rotates the impellers. These pumps are reasonably simple and straightforward to operate. The pump operator simply opens the small “bung hole” at the top of the barrel, and inserts the tube, or hose at the bottom of the housing into the barrel. The hose leading from the side or top of the pump housing is placed in the container to be and the pump is started.
For the most part, barrel pumps are used in the chemical, petroleum, and food industries. Therefore, barrel pumps are ordinarily used to pump volatile or toxic fluids, such as acids, alkalis, combustible solvents, and petroleum products. The food processing industry uses a special type of barrel pump called a “sanitary barrel pump.”
The most popular barrel pumps, especially in chemical and petroleum facilities, are hand operated. The operator of a hand-cranked barrel pump simply turns a crank located at the pump housing to operate the pump. There are, however, some barrel pumps that are electrically operated, as well as pumps that are pneumatically operated, or air-driven. An electrically operated barrel pump is very seldom used where volatile chemicals, solvents, oil, gasoline, etc. are handled, for obvious reasons. A pneumatic barrel pump requires air hoses, compressors, and other costly and bulky equipment, thus are also used infrequently.
There are, as well, barrel pumps designed for smaller containers, such as 30 gallon (24.98 liter) barrels, and five gallon (4.16 Liter pails. Many of these are known as high viscosity barrel pumps, since these smaller containers often contain grease, glue, and other high-viscosity liquids. Most chemical, petroleum, and food processing fluids are lower viscosity, thus they weigh less, and a 55 gallon barrel is adequate to contain these more free-flowing liquids.
Occasionally, barrel pumps will be modified to mount a metering system. Metered pumps are also sold as a unit, but are fairly expensive in comparison with the smaller meters that can be easily mounted and unmounted. These metered pumps keep track of the amount of liquid pumped.