2003-01-19
A good source of info on units is:
There are 4 definitions for the barrel:
barrel (bbl or brl or bl) [1]
a commercial unit of volume used to measure liquids such as beer and wine.
The official U. S. definition of the barrel is 31.5 gallons, which is
about 4.211 cubic feet or 119.24 liters. This unit is the same as the
traditional British wine barrel. In Britain the barrel is now defined to be 36
imperial gallons, which is substantially larger: about 5.780 cubic feet or
163.66 liters. This unit is slightly larger than the traditional British beer
and ale barrel, which held 5.875 cubic feet or 166.36 liters. There are other
official barrels, defined in certain U.S. states; most of them fall in the
general range of 30-40 gallons. A barrel of beer in the U.S., for example, is
usually 31 U.S. gallons (117.35 liters). The origin of the standard symbol
bbl is not clear. The "b" may have been doubled originally to indicate
the plural (1 bl, 2 bbl), or possibly it was doubled to eliminate any confusion
with bl as a symbol for the bale (see above).
barrel (bbl or bo) [2]
a commercial unit of volume used to measure petroleum. By international
agreement a barrel of petroleum equals 42 U. S. gallons, which is
about 158.987 liters. The symbol bo (barrel of oil) is used for this unit
in the petroleum industry. The petroleum barrel originated in the Pennsylvania
oilfields (the first commercial oilfields) in the late nineteenth century.
Apparently, 40-gallon barrels were increased to 42 gallons to provide insurance
aganst any spillage or underfilling. By coincidence (it seems), this unit is the
same size as the traditional tierce, a wine
barrel.
barrel (bbl or brl or bl) [3]
a commercial unit of volume used to measure dry commodities such as apples.
The U. S. dry barrel, established by Conress in 1912, is 105 dry quarts, which is
about 4.083 cubic feet or 115.63 liters. (This is the only case in the United
States customary system where a dry volume is less than the corresponding fluid
volume.) For certain commodities, other sizes are traditional in the U.S.; for
example, a barrel of sugar was traditionally 5 cubic feet (about 141.58 liters).
barrel (bbl) [4]
a commercial unit of weight, varying with the commodity being measured. In
the U.S., for example, a barrel of flour traditionally holds 196 pounds (88.90 kg)
and a barrel of beef, fish, or pork 200 pounds (90.72 kg). A barrel of cement is
traditionally equal to 4 bags, which is 376 pounds (170.55 kg) in the U.S. and
350 pounds (158.76 kg) in Canada.
And the BTU is:
British thermal unit (Btu)
a unit of heat energy defined as the amount of heat required to raise the
temperature of one pound of water by one degree Fahrenheit. In America the
British thermal unit is sometimes called the heat unit. In
defining the Btu, it is necessary to specify the temperature of the water; thus
there have been several definitions over the years. However, one Btu is equal to
about 251.996 (small) calories, or
0.251 996 of the (kilo-)calories counted by dieters. Using the current
definition of the calorie (the IT calorie), one Btu equals approximately 778.169
foot pounds, 1.055 056 kilojoules or 0.293
071 watt hour.
The symbol BThU has also been used, especially in Britain.
to determine what 42 gallons is, you need to be specific as to what gallon
you are speaking of. The gallon also has 4 definitions:
gallon (gal) [1]
a traditional unit of liquid volume, derived from the Roman galeta,
which originally meant a pailful. Gallons of various sizes have been used in
Europe ever since Roman times. In the United States, the liquid gallon is
legally defined as exactly 231 cubic inches; this is equal to the old English
wine gallon, which originated in medieval times but was not standardized
until 1707, during the reign of Queen Anne. Some scholars believe the wine
gallon was originally designed to hold 8 troy pounds of
wine. The U. S. gallon holds 4 liquid quarts or exactly
3.785 411 784 liters; a U.S.
gallon of water weighs about 8.33 pounds. American colonists were also familiar
with the Elizabethan beer and ale gallon, which held 282 cubic inches
(4.621 liters).
gallon (gal) [2]
a historic British unit of dry volume still used implicitly in the U.S. In
the U. S., the term "gallon" is not used in dry measure, but if it were it would
be equal to 1/2 peck, or 4 dry
quarts, or 268.8025 cubic inches, or approximately 4.404 884 liters. This unit
is the English corn or grain gallon, standardized during the reign
of Elizabeth I in the sixteenth century. The earliest official definition of a
dry gallon in Britain is a 1303 proclamation of Edward I, where the gallon is
defined as the volume of 8 pounds of wheat; the current U.S. "gallon" contains
about 7.5 pounds of wheat. Grain gallons have tended to be larger than liquid
gallons throughout the history of British units, apparently because they were
based on heaped rather than "struck" (leveled) containers. A container in which
grain has been heaped above the top will hold as much as 25% more grain, and the
traditional corn gallon is in fact 16.4% larger than the wine gallon.
gallon (gal) [3]
currently the British use a larger gallon than either of the American
gallons. The Imperial Weights and Measures Act of 1824 established a new unit
for all volumes, liquid or dry, replacing all the other gallons in previous use
in Britain. The imperial gallon, designed to contain exactly 10
pounds of distilled water under precisely defined conditions, holds exactly
4.546 09 liters
or approximately 277.4194 cubic inches. The imperial gallon equals 1.20095 U.S.
liquid gallons (British wine gallons) or 1.03206 U.S. dry gallons (British corn
gallons).
gallon (gal) [4]
a traditional unit of volume in Scotland equal to 4 Scots quarts. This is
almost exactly 3 British Imperial gallons, 3.6 U.S. liquid gallons, or 13.63
liters.
Thus, a conversion of 42 gallons to litres depends on which gallon to litre
conversion factor applies. However the 2-nd definition of the barrel above
states the 42 gallon type as being US gallons. Since 1 gallon US is 3.785
411 L; 42 gallons would be about 159 L.
As for the origins of the term barrel as used for oil, you may want to
write to the guy who runs this website and see if he knows:
[EMAIL PROTECTED]
I'm sure we could guess, but that is not what you are looking for.
John
----- Original Message -----
Sent: Saturday, 2003-01-18 16:23
Subject: [USMA:24491] Help Needed
> I am writing a
paper that I have about 1 week to finish
> I need to know where the barrel
of oil term comes from and what is 42 US
> galllons in SI.
>
> What is a BTU in SI?
>
> I have to get this right hence my
asking
>
> John Nichols BE, Ph.D. (Newcastle), MIE (Aust),
Chartered Professional
> Engineer
> Assistant Professor
>
Texas A&M University
> Department of Construction Science
>
Langford AC
> Rm: A414 MD 3137
> College Station, TX
77843-3137
>
> Electronic mail: [EMAIL PROTECTED]>
Telephone: 979 845 6541
>
Facsimile: 979 862
1572
>
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> a
fronte praecipitium a tergo lupi
>
> in front a precipice,
behind a wolf
>
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