Document wDJMypyx9E8J86bzNV1eb236B

American Society of Heating and Ventilating Engineers Guide, 1934 Table 2. Commercial Standard Fuel Oil Specifications a n*tnn.A t>-- ............. - - ~ -- -- Grade of Oil No. 1 Light Domestic . Fuel Oil A light distillate oil for use in burners requir ing a high grade fuel. Approx Btu per Gal. Flash Min. Point Max. Water and Sediment, Maximum * Pour Point. Maximum Distillation Test Viscosity Maximum 139,000 110 F 165 F or legal or legal 0.05% 15 F 10% point End point, maximum maximum 420 F '600 F No. 2 Medium Domestic Fuel Oil A medium distil late oil for use in burners re quiring a high grade fuel. 141.000 125 F 190 F or legal or legal 0.05% 15 F 10% point, 00% point, maximum maximum 440 F 620 F No. 3 Heavy Domestic Fuel Oil A distillate fuel oil for use in burners where a low viscosity oil is required. 143.400 150 F 200 F or legal or legal 0.1% 15 F 10% point, 90% point, maximum maximum Saybolt Universal 460 F at 100 F 675 F 55 seconds However, ^hese specifiratior^s^l^f n^u^re^iwur^hf^fessThan^f^un^eTany'conditions.5* B. Detailed Requirements for Industrial Fuel Oils Grade op Oil No. 4. Light Industrial Fuel Oil An oil known to the trade as a light fuel oil for use in burners where a low vis cosity industrial fuel oil is required. Approx Btu per Gal. Flash Point. Min. Max. Water and Sediment. Maximum Pour Point, Maximum Viscosity, Maximum 144,500 150 F. See Note b 1.0% See Note e Saybolt Universal at 100 F 125 seconds ,, No. S Medium Industrial Fuel Oil Same as Federal Specifications Board specification (or bunker oil "B" for burners adapted to the use of industrial fuel oil of medium viscosity. 146,000 150 F 1.0% Saybolt Furol at 122 F 100 seconds ,, N-6 Heavy Industrial Fuel Oil Same as Federal Specifications Board specification lor bunker oil "C" for 150,000 burners adapted to oil of high viscosity. 150 F Water sediment 1.75% 0.25% Saybolt Furol at 122 F 300 seconds "wcenever required, as for example in burners with automatic ignition. a maximum flash point'may cboensdpiteiocnifsie.d. However, these specifications shall not require a flash point less than 250 F under any cpour point may be specified whenever required by conditions of storage and use. However, these specifications shall not require a Dour point less than 15 F under any conditions. use, while the last three were suitable only for commercial and industrial burners. This differentiation has not proved stable, and today domestic installations are using Nos. 4 and 5 of the so-called heavy-oil group. Several burners adapted to domestic use have recently been listed for automatic operation with No. 5, or even No.. 6, oil. Usually oils Nos. 5 or 6 require 374 Chapter 27--Fuels and Combustion preheating for proper operation, but where conditions are favorable, No. 5 can be used without the equipment that this entails. There are two reasons for the trend to lower grades of oil. While the lighter oils contain slightly more heat units per pound, the weight per 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(f to 4ff 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 has split the tank of the truck delivering oils for domestic use into compart ments of 400 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. CAS Gas is broadly classified as being either natural or 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 certain amount of ljeat. 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 cool the products of combustion down below their dew-point, which is ordinarily in the neighborhood of 130 F. 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 CO2, 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 3 shows typical values for the three main oil fields, although values from any one field vary materially. Table 3 also gives the calorific values of the more common types of 375