Barrel (volume)

The barrel is the name of several units of volume, generally in the range of about 100-200 L (30-50 US gallon).

Dry goods

* US dry barrel: 7,056 cubic inches (~3.28 bushel / 115.6 litres).
**Defined as “length of stave 28.5″, diameter of head 17.125″, distance between heads 26″, circumference of bulge 64″ outside measurement; representing as nearly as possible 7,056 cubic inches; and the thickness of staves not greater than 0.4″.” [http://uscode.house.gov/download/pls/15C6.txt 15 USC 234] ] (≈ 724mm, 435mm, 660mm, 1626mm [Ø ≈ 20.37″/517mm] , 10mm) And any barrel that is 7,056 cubic inches is recognized as equivalent.
* US barrel for cranberries 5,826 cubic inches (~2.71 bushel / 95.47 litres)
** Defined as “length of stave 28.5″, diameter of head 16.25″, distance between heads 25.25″, circumference of bulge 58.5″ outside measurement; and the thickness of staves not greater than 0.4″.” (≈ 724mm, 413mm, 641mm, 1486mm [Ø ≈ 18.62″/473mm] , 10mm) No equivalent in cubic inches is given in the statute, but later regulations specify it as 5,826 cubic inches. [ [http://www.sizes.com/units/barrel_cranberry.htm cranberry barrel ] ]

Some products have a standard weight or volume that constitutes a barrel
*cornmeal, 200 pounds (90.7 kg)
*Portland cement, four cubic feet (113 L) or 376 pounds (170.6 kg). [cite web| title = U.S. Traditional and Commercial Barrel Sizes| publisher = 2000 Sizes, Inc.| url = http://www.sizes.com/units/barrel_USconv.htm| accessdate = 2007-04-26]
*sugar, five cubic feet (141 L)
*wheat or rye flour, three bushels or 196 pounds (88.9 kg).
*lime (mineral), 280 lb (127 kg) large barrel, or 180 lb (81.6 kg) small barrel. [http://uscode.house.gov/download/pls/15C6.txt 15 USC 237] ]

Liquid Volume (other than oil)

* UK beer barrel: 36 UK gallons (163.7 litres).
* UK wine barrel: 26.25 UK gallons (119.3 litres).
* US beer barrel: 31 US gallons (117.3 litres), the result of tax law definitions.
* US non-beer liquid barrel: 31½ US gallons (119.2 litres), or half a hogshead.
* Somali water barrel: 200 litres - used in Horn of Africa to measure water and diesel.

Oil barrel

* Oil barrel: 42 US gallons, 158.9873 litres,cite web |author=B. N. Taylor |publisher=NIST |work=Guide for the Use of SI units |url=http://physics.nist.gov/Pubs/SP811/appenB8.html#B |title=B.8 Factors for Units Listed Alphabetically - Section B |accessdate=2007-10-18] or 34.9723 Imperial (UK) gallons.

The standard oil barrel of convert|42|usgal|L|sigfig=3 is used in the United States as a measure of crude oil and other petroleum products. Elsewhere, oil is commonly measured in cubic metres (m³) or in tonnes (t), with tonnes more often being used by European oil companies. International companies listed on American stock exchanges tend to convert their oil production volumes to barrels for global reporting purposes, and those listed on European exchanges tend to convert their production to tonnes.

The wooden oil barrel of the late 1800s is different from the modern day 55-gallon steel drum (known as the 44-gallon drum in Britain and the 200-litre drum in Australia). The 42-US gallon oil barrel is a unit of measure, and is no longer used to transport crude oil - most petroleum is moved in pipelines or oil tankers.

The 42 US gallon size of barrel as a unit of measure is largely confined to the American oil industry, since other sizes of barrel were used by other industries in the United States, and nearly all other countries use the metric system. Many oil producing countries that did not have the technical expertise to develop their own domestic oil industry standards use the American oil barrel because their oil industries were founded by U.S. oil companies.

The measurement originated in the early Pennsylvania oil fields. In the early 1860s, when oil production began, there was no standard container for oil, so oil and petroleum products were stored and transported in barrels of different shapes and sizes for beer, fish, molasses, turpentine, etc. Both the 42-US gallon barrels (based on the old English wine measure), the tierce (159 litres) and the 40-U.S.-gallon (151.4-litre) whiskey barrels were used. 45-gallon barrels were also in common use. The 40-gallon whiskey barrel was the most common size used by early oil producers, since they were readily available at the time. [ cite web | author=Judith O. Etzel | title=The 42 Gallon Barrel (History) | work=The 150th Anniversary of Oil | date=2008 | url=http://www.oil150.com/essays/2007/08/the-42-gallon-barrel-history | publisher=Oil Region Alliance of Business, Industry and Tourism |accessdate=2008-04-11 ]

The origins of the 42-gallon oil barrel are obscure, but some historical documents indicate that around 1866 early oil producers in Pennsylvania came to the conclusion that shipping oil in a variety of different containers was causing buyer distrust. They decided they needed a standard unit of measure to convince buyers that they were getting a fair volume for their money. They agreed to base this measure on the more-or-less standard 40-gallon whiskey barrel, but added an additional two gallons to ensure that any measurement errors would always be in the buyer's favor as an additional way of assuring buyer confidence (The same principle as behind the baker's dozen and some other "long" units of measure.Fact|date=July 2008) By 1872 the standard oil barrel was firmly established as 42 US gallons. [ cite web | title=Barrel (of petroleum) | work=Units and Systems of Units | date=2004 | url=http://www.sizes.com/units/barrel_petr.htm#ft5 | publisher=Sizes, Inc | accessdate=2008-04-11 ]

The abbreviations 1 Mbbl and 1 MMbbl have historically meant one thousand and one million barrels respectively. They are derived from the Latin "mille" meaning "thousand" rather than the Greek "mega". However, this can cause confusion with the SI abbreviation for Mega- (and in non-industry documentation Mbbl, "megabarrel", can sometimes stand for one million barrels).

ee also

* 55 gallon drum
* United States customary units
* Imperial unit
* Petroleum
* Petroleum pricing around the world
* Barrels per day (BPD)

References

External links

* [http://calcme.com/calc/oil01 Crude Oil and Oil Products Conversions]
* [http://calcme.com/calc/oil02 Oil Industry Unit Conversions]