Document vBqmv088LkmX4eoNm0qwO1DX8

American Society of Heating and Ventilating Engineers Guide, 1932 Table 10. Linear Expansion of Solids at Ordinary Temperatures3 (Tabular values represent increase perfoot per 100 deg increase in temperature, Fahrenheit). Substance Glass (Emzlish flint) Granite (avpxa^p) Iron (cast) Iron (soft forged) Iron (wire) Temp. Coefficient Conditions b per 100 Dbg. Fa an. Dbg. Fahr. Substance Temp. Coefficient Conditions b per 100 Deq. Fahr. Deg. Fabr. 32 to 212 32 to 212 32 to 212 32 to 212 32 to 212 104 Oto 212 32 to 212 0.001042 0.001072 0.000926 0.000451 0.000482 0.000589 0.000634 0.000800 32 to 212 Steel (Bessemer rolled, hard). Steel (Bessemer rolled, soft)__ 8teel (cast, French)..... ............ Steel (cast annealed, English). 32 to 212 Oto 212 Oto 212 104 104 0.001505 0.009Q84 0.000139 0.00056 0.00063 0.000734 0.000608 oFrorn Mechanical Equipment of Building,, VoL I, by Harding and Willard, revised edition, 1929. bWhere range of temperature is given, coefficient is mean over range. eCoefficient of cubical expansion. gas, then ^ or Px Vi V 2 Jr 1 Pi Vi, but since Pi Vi for any given case is a definite constant quantity, it follows that the product of the absolute pressure and volume of a gas is a constant, or P V -- C, when T is kept constant. Any change in the pressure and volume of a gas at constant temperature is called an isothermal change. Charles' Law refers to the relation between pressure, volume and tem perature of a gas and may be stated as follows: The volume of a given weight of gas varies directly as the absolute temperature at constant pressure, and the pressure varies directly as the absolute temperature at constant volume. Hence, when heat is added at constant volume, Vc, the resulting PT equation is -- = ~, or, for the same temperature range at constant pres- Pi Pi' sure, Pc, the relation i.s Vi .7 = II Vq 7V In general, for any weight of gas, W, since volume is proportional to weight, the relation between P, V and T is where PV = WRT (2) P = the absolute pressure of the gas in pounds per square foot. V = the volume of the weight W in cubic feet. W = the weight of the gas in pounds. R = a constant depending on the nature of the gas. T = the absolute temperature in degrees Fahrenheit. This is the characteristic equation for a perfect gas, and while no gases are perfect in this sense, they conform so nearly that Equation 5 will apply to most engineering computations. 544 Chapter 40 GENERAL INFORMATION Codes and Standards; Greenhouse Heating; Specifications; Humidification for Residences; Panel Heating System; Sound Level; Trouble Shooting. CODES AND STANDARDS THE following codes and standards relating to the design, installation, testing, rating and maintenance of materials and equipment used for the heating and ventilation of buildings, have been adopted by the American Society of Heating and Ventilating Engineers : Subject Air purity Title ' Synthetic Air Chart Boilers (testing) Standard and Short-Form Heat Balance Codes for Testing Low Pressure Steam Heating Solid Fuel Boilers (Codes 1 and 2) Boilers (testing) Performance Test Code for Steam Heating Solid Fuel Boilers (Code 3)a When ADOPTED June, 1917 June, 1929 June, 1929 Reference A.S.H.V.E. Transactions, Vol. 23, p. 607, and The Guide, 1931 A.S.H.V.E. Transactions, Vol. 35, 1929. Reprints available A.S.H.V.E. Transactions, Vol. 35, 1929. Reprints available Boilers-- Oil Fuel (testing) Code for Testing Steam Heat ing Boilers Burning Oil Fuel January, 1931 Heating, Piping and Air Conditioning, March, 1931 Boilers (rating) Code for Rating Steam Heat ing Solid Fuel Hand Fired Boilers April, 1930 A.S.H.V.E. Transactions, Vol. 36, 1930 Ethics Code of Ethics for Engineers January, 1922 A.S.H.V.E. Transactions, Vol. 28, 1922, p. 6 (See also p. xiv Guide, 1932) Fans Standard Test Code for Disc and Propeller Fans, Centrifugal Fans and Blowers. May, 1923. Revised June, 1931 A.S.H.V.E. Transactions, Vol. 29,1923, p. 407b ^Originally adopted t>y the National Boiler and Radiator Manufacturers Association. bAlso, see Healing, Piping and Air Conditioning, August, 1931, p. 743. . 545