Document oe0KkxR9GynM38bY5nwxG1kro

624 CHAPTER 28 1953 Guide TaBI.F! 5, Area of Flanged Fittings, Square Feet* Flanged Nominal' Coupling Pipe Size (Inches) Standard Extra Heavy 90 Deg .Ell Standard .Extra Heavy Long Radius Ell Standard Extra Heavy Tee Standard Extra Heavy Cross Standard Extra Heavy 1 iI)K2 2 2H .3 3H 4* m 5 6 8 ,10 12 0.320 0.383 0.477 0.672 0.841 0.945 1.122 1.344 1.474 1.622 1.82 2.41 3.43 . 4.41 0.438 0.510 0.727 0.848 1.107 1.484 1.644 1.914 2.04 2.18 2.78 3.77 5.20 0.71 0.795 1.015 01957 1.098 1.174 1.332 1.65 2.01 2.09 2.57 2.38 .3.49 2.98 3.96 3.53 4.64. 3.95 5.02 4.44 5.47 5.13 6.99 6.98 9.76 10.18 13.58 13.08 17.73 0.892 1.083 1.084 1.340 1.337 .. 1.874 1.84 2.16 2.32 2.76 2.68 3.74 3.28 4.28 ` 3.96 4.99 4.43 5.46 5.00 6.02 5.99 7.76 8.56 11.09 12.35 15.60 16.35 - 18.76 1.235 1.481 1.815 2.54 3.21 3.66 4.48 5.41 6.07 6.81 7.84 10.55 15.41 19.67 1.575 1.925 2.68 3.09 4.05 5.33 6.04 7.07 7.72 8.52 10.64 14.74 20.41 26.65 1.622 1.943 2.38 3.32 4.19 4.77 5.83 .7.03 ' 7.87 8.82 10.08 13.44 19.58 24.87 , 2.07 2.53 *3.54 4.06 5.17 6.95 7.89 9.24 10.07 10.97 . 13.75 . 18.97 26.26 34.11 * Including areas of accompanyingflanges bolted to the fitting. Standard _ thicknesses of 85 percent magnesia pipe covering are not exactly 1 in. However, the loss through any given thickness of insolation can be obtained by interpolation. Also, the losses through any of the insulations given in Table 6 can be obtained by multiplying the losses obtained from Figs. 1, 2, or 3 by the factors given in Table 7. Pipes operating at high temperatures are frequently insulated to the Table 6. Thermal Conductivity (k) op Various Type Pipe Insulations ' fob Medium and High Temperature Pipe* Expressed in Btu per (hour) (square foot) (Fahrenheit degree temperature difference ' per inch) ,4 Types op Insulating Materials Density Temp. Range op Accepted - Use' - Mean Temperature, F Deo 100 200 300 400 500 Corrugated Asbestos--Type Laminated Asbestos--Type Mineral Wool--Type.................... ................. 11-13 15-17 10-15 13-15 Up to 600 F Up to 300 F Up to 300 F Up to 300 F Up to 700 F Up to 1900 F Up to 1200 F 0.39 0.45 0.51 0.57 0.68 0.80 0.51 0.59 0.69 0.49 0.57 0.65 0.39 0.40 0.63 0.34 0.44 0.45 0.66 0.39 0.49 0.50 0.69 0.44 0.54 0.55 0.72 0.49 0.75 0.54 ' * Average values from laboratories for insulating materials of various manufacturers. Table 7. Pipe Covering Factors Types op Insulating Materials Temperature Dippehence, Pipe to Air, F Deg 100 200 300 400 500 Corrugated Asbestos--Type Laminated Asbestos--Type........... ........... ................. Mineral Wool--Tvpe.................. ....................................... Diatomaceous Silica--Type..........................:.................. Brown Asbestos Fiber--Typ............................................ 1.30 1.19 . 1.15 0.96 0.98 1.37 0.86 1.36 1.23 1.19 0.98 1.00 1.36 0.88 1.42 1.27 1.23 1.00 1.02 1.35 0.91 1.02 1.05 1.35 0.93 - 1.04 1.07 1.34 0.96 Pipeflnstilation 625 best advantage by combining a high temperature insulation near, the pipe with a. moderate or low temperature insulation around it as an outer.layer: By this method an efficient material may be used for each of the two tem perature ranges encountered. In calculating the heat loss through such a 40 80 120 160 200 240 280 TEMP DIFF FROM PIPE TO ROOM. F DEG Fig. 1. Heat Loss Through X In. Thick 85 percent Magnesia Type Covering combination the mean temperature of each layer must be determined along with the thickness of each. This is readily done in three or four calculations performed as a series of approximations, in which assumptions of thickness and mean temperature are adjusted as indicated in the dis cussion which follows. In the case of a single thickness of pipe covering, the quantity of heat