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Engineers Guide, 1935
Table 3. Commercial Standard Fuel Oil Specifications** A. Detailed Requirements for Domestic Fuel Oils
Grade of Oil
Approx. per
No. 1 Domestic
Fuel Oil A light distillate
139.000
oil for use in burners_requij- _ Inga high grade
Flash Point
Min. Max.
110 F 165 F or legal
Water AND
Maximum
0.05%
Pour I
Point.* | Maximum
Distillation Test
1 /ISCOSITY Maximum
10% point, maximum
End point, maximum
15 F
420 F
600 F
-
No. 2 Domestic Fuel Oil A medium distil late oil for use in burners re-1 qiiiring a high
141.000 1 125 F 190 F or legal
0.05%
15 F
10% point, maximum maximum
440 F
620 F
No. 3. Domestic Fuel Oil , A distillate fuel oil for use in burners where a low viscosity oil
is required.
143.400 150 F or lega
200 F
0.1%
15 F
110% point I maximum
maximum
Universal at 100 F
460 F
675 F 65 seconds
Detailed Requirements for Industrial Fuel Oils B.
Grape of Oil
Approx.
Btu PER Gal>
Flash Point. Min. Max.
Water AND
Sediment. Maximum
Pour Point.*
Maximum
No. 4. Industrial Fuel Oil a ,, nil known to the trade as a lisht fuel on lor SS"n buruera where a low via-
144.500
150 F7~See~ Note*
1.0%
See Note*
V.SCOSITY. Maximum
Saybolt Universal at 100 F 125 seconds
No. 5 Industrial Fuel OU
Same as Federal SpedtoUons Beard KemadapS tortile use ofindus' trial fuel oil of medium viscosity.______
146.000 [
No. 6 . ~., Industrial Fuel Oil Same as Federal Specifications Board
150.000
150 F 150 F
1.0%
1 Water 1 sediment
1.75% 0.25%
Furol at 122 F 100 seconds
Saybolt Furol
at 122 F 300 seconds
merce. Burn u of SionddJ ds. Commercial
... .
`Loweemr oinrehnitgshpeercpifiocuartiopnosindtso mnoatygbiveesBpetucifpieedr gwahlelonne,vberutretqhueiyreadrebuyuc^ounditions of_s_t_orage and useHowever, these specifications shall not require a pour point less than 0 F under any conditions.
.^Whenever required, as for .example in burners with automatic igmtion.a maximum flash point may 3e specified. However, these specifications shall not require a flash point less than 250 F under any
Pour point may be specified whenever required by conditions of storage and use. However, these renditions. specifications shall not require a pour point less than 15 F under any conditions. -
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27Chapter --Fuels and Combustion
gallon increases more rapidly than the decrease in heat units per pound, and oil is bought by the gallon. As a consequence, while a No. 1 oil may contain 139,000 Btu per gallon, oil No. 5 may test 146,000 Btu per gallon, or 6 per cent more. Usually there is a differential of 3(* to 4 between the No. 1 and No. 5 oils, so that the economy of buying the heavier fuels is apparent; there remains the economic utilization of the heat content of the heavier oils.
The cost of oil fuel is dependent also upon the amount that can be delivered at one time, and the method of delivery., Common practice hassplit thetank-of- the truck delivefingoils for domestic use into compart ments of 150 to 500-gal capacity, and these unit dumps are made the basis of price. Where a truck can be connected to a storage-tank fill and quickly discharge its oil by pump, the price obviously can be less than where a smaller quantity must be drawn off in 5-gal cans and poured. For similar reasons an installation that can be supplied from. a.tank car on a siding provides for a lower unit fuel cost than one where the oil must be trucked, even in the large trucks holding 2,000 gal or more that are used for distributing the heavier oils.
GAS
Gas is broadly classified as being either natural ot manufactured. Natural gas is a mechanical mixture of several combustible and inert gases rather than a chemical compound. Manufactured gas as dis tributed is usually a combination of certain proportions of gases produced by two or more processes, and is often designated as city gas.
When gas is burned a large amount of water vapor is produced as one of the products of combustion. This: ordinarily-escapes up the chimney, carrying away with it a certainamount of heat. However, when the heat value of gas is determined in an ordinary calorimeter, this water vapor is condensed and the latent heat of vaporization that is given up.during the condensation is reported ;as a. portion of the heat value .of the gas. The heat value so determined is termed the gross or higher heat value and this is what is ordinarily meant when the heat value of gas is specified. The heat that is reclaimed by the condensation of the water vapor amounts to about 10 per cent of the total heat'value. It is impractical to utilize the'entire higher heat value of-the gas in:any house-heating appliance, because to do so it would be necessary to cook the products of combustion down below their dew point, which is ordinarily in the neighborhood of . 130 F........................... . w
Natural gas is the richest of the gases-and contains from 80 to'95 per cent methane, with small percentages of the other combustible hydrocarbons. In addition, it contains from 0.5 to 5.0 per cent of COj, and from 1 to 12 or 14 per cent of nitrogen. The heat value varies from 700 to 1,500 Btu per cubic foot, the majority of natural gases averaging about 1,000 Btu per cubic foot; Table-4 shows typical values foK'the three main oil fields, although values from any one field vary materially;
Table 4 also gives the. calorific values of the more common types of manufactured gas. Most states have legislation which controls the distri bution of gas and fixes a minimum limit to its heat content. The 'gross
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