Constructed most often from carbon steel or stainless steel, steel barrels or steel drums are durable and cost-effective, allowing a manufacturer to get many uses from the same drum and then recycle it once it is finished being used.
Steel barrels can be either closed top or open top depending on their intended application. Closed top drums will usually have two bung openings, one for pouring and the other for venting, as the lid is manufactured to be sealed to the body of the drum. Open top drums have removable lids which are used connected to the drum with a gasket or seal made out of neoprene or another polymer or rubber to ensure a tight seal. These lids can be then be secured closed with a bolt or lever lock system depending on the contents of the drum and the required security.
Barrels are typically constructed according to standard configurations in order to ensure they can be processed with generic tumbling and stacking machinery, as well as other drum handling equipment. As industrial drums are used for product transportation, they are required to meet certain conditions in terms of material quality, construction methods and final product standards etc. Testing that barrels undergo to ensure they meet these stringent standards includes water spray, leak testing, free drop, penetration and stacking tests.
Due to their sealed and durable exteriors, certain barrels may be specifically designed to carry flammable, toxic and otherwise hazardous waste materials in order to dispose of them or relocate them to an area in which they may be used. Steel barrels are used to ensure that the materials are not leaked or exposed at any point along their transportation route.
Any number of liquids or solids, or a combination of the two may be stored or transported in steel barrels. They can also be used for the storage of wine and beer in place of the more traditional wooden barrel. For sensitive materials or applications, seamless steel barrels can be constructed from stainless steel, providing a sanitary environment for a liquid or other product.
Military spec barrels can be manufactured by some barrel makers to be used in the transportation of military products and materials. The construction standards for these drums are even higher than for commercial drums and manufacturers have to pay particular attention to the requirements. In addition to the locking systems on open top barrels, some manufacturers are able to place a safety seal, or tamper proof seal on the lids of the barrels to guarantee the product inside is free from contamination.