Document jyOjK1kYMNpZoQNkaOn90j5QO

Heating Ventilating Air Conditioning Guide 1938 Table 6. Length in Feet of Pipe to be Added to Actual Length of Run-- Owing to Fittings--to Obtain Equivalent Length Size of Pipe Inches St'd. Elbow Side Outlet Tee Gate Valve Globe Valve Angle Valve Length in Feet to be Added to Run 2 2H 3 m 4 5 6 7 89 10 12 14 5 16 7 20 10 26 12 31 14 35 18 44 22 50 26 55 31 63 35 69 39 76 47 90 53 105 2 18 9 3 25 12 3 33 16 4 39 19 5 45 22 7 57 28 9 70 32 10 82 37 12 94 42 13 105 . 47 15 118 52 18 140 63 20 160 72 Example of length in feet of pipe to be added to actual length of run. nfAsuseo lchsth. - m.-o. h......m.Jfc -t---------------- ! BaumLEHT UH6TH - 193-0' til TABLES FOR PIPE SIZING1 Factors determining the size of a steam pipe and its allowable limit of capacity are as follows: 1. Pipe condensate flowing with steam. 2. Pipe condensate flowing against steam. 3. Pipe and radiator condensate flowing with steam. 4. Pipe and radiator condensate flowing against steam. It is apparent that (3) and (4) are practically limited to one-pipe systems while (1) and (2) cover all other systems. Tables 7 and 8, worked out for determining pipe sizes, have their col umns lettered continuously, Columns A through L being in Table 7, and M through EE in Table 8. In the following text, reference made to columns will be by letter. The tables are based on the actual inside diameters of the pipe and the condensation of. ]/i lb (4 oz) of steam per square foot of equivalent direct radiation (abbreviated EDR) per hour. The drops indicated are drops in pressure per 100 ft of equivalent length of run. The pipe is.assumed to be well reamed without unusual or notice able defects. 1Pipe size tables in this chapter have been compiled in simplified and condensed form for the convenience of the user; at the same time all of the information contained in previous editions of The Guide has been retained. Values of pressure drops, formerly expressed in ounces, are now expressed in fractions of a pound. *As steam system design has materially changed in recent years so that 240 Btu no longer expresses the heat of condensation from a square foot of radiator surface per hour, and as present day heating units have different characteristics from older forms of radiation, it is the purpose of The Guide to gradually eliminate the empirical expression square foot of equivalent direct radiation. EDR, and to substitute a logical unit based on the Btu.. The new terms to express the equivalent of 1000 Btu (Mb), and 1000 Btu per.hour (Mbh), have been approved by .the A.S.H.V.E. 306 Chapter 16. Piping for Steam Heating Systems Table 7 may be used for sizing piping for steam heating systems by determining the allowable or desired pressure drop per 100 equivalent feet of run and reading from the column for that particular pressure drop. This applies to all steam mains on both one-pipe and two-pipe systems, vapor systems, and vacuum systems. Columns B to G, inclusive, are used where the steam and condensation flow in the same direction, while Columns H and / are for cases where the steam and condensation flow in opposite directions, as in risers and runouts that are not dripped. Columns J, K, and L are for one-pipe systems and cover riser, radiator valve, and vertical connection sizes, and radiator and runout sizes, all of which are based on the critical velocities of the steam to permit the counter, flow of condensation without noise. Sizing of return piping may be done with the aid of Table 8 where pipe capacities for wet, dry, and vacuum return lines are shown for the pressure drops pier 100 ft corresponding to the drops in Table 7. It is customary to use the same pressure drop on both the steam and return sides of a system. Table 7. Steam Pipe Capacities Capacity Expressed in Square Feet of Equivalent Direct Radiation (Reference to this table will be by column letter A through L) This table is based on pipe size data developed through the research investiga tions of the American Society of Heating and Ventilating Engineers. CAPACITIES OF STEAM MAINS AND RISERS Direction of Condensation Flow in Pipe Lute Special. Capacities fob Onb-Pepe Systems Only Pipe - Size ;IN. A With the Steam in One-Pipe and Two-Pipe Systems J/s lb 1/i4 lb l/s lb or or HO. HOt 10* Drop Drop. Drop. Hlb 20. Drop Hlb 4 0s Drop Hlb 80s Drop BCD B F a Against the Steam Two-Pipe Only Vertical Honsontal Supply Risers UpFeed Radiator Radiator and and - Riser Run- nections /o Jb K La X 30 l 39 46 56 79 Tii 30 157 5fr 26 IX 87 100 122 173 245 346 122 58 m .134 155 190 269 380 538 190 95 2 273 315 386 546 32X 449 518 635 898 822 948 1,163 1,645 3X 1,228 1,419 1,737 2,457 771 1,270 2,326 3,474 1,091 1,797 3,289 4i913 386 635 1,129 1,548 195 395 700 1,150 4 1,738 2,011 2,457 3,475 4,914 6,950 2,042 1,700 5 3,214 3,712 4,546 6,429 9,092 12,858 3,150 6 5,276 6,094 7,462 10,553 14,924 21,105 8 10,983 12,682 15,533 21,967 31,066 43,934 10 20,043 23,144 28,345 40,085 56,689 80,171 12 32,168 37,145 45,492 64,336 90,985 128,672 16 60,506 69,671 84,849 121,012 169,698 242,024 -- -- 25 45 98 152 288 464 799 1,144 1,520 -- 20 20 55 55 81 81 165 165 260 475 745 1,110 2,180 ---- A0 Horizontal Mains and Down-Feed Risers UpFeed Risers Mains and Un Updripped Feed Run -Risers outs Radiator Con- nections Run outs Not Dripped Note.--All drops shown are in pounds per 100 ft of equivalent run--based on pipe properly reamed. Do not use Column H for drops of 1/24 or 1/32 lb; substitute Column C or Column B as required. bDo not use Column J for drop of 1/32 lb except on sizes 3 in. and over; below 3 in. substitute Column B. On radiator runouts over 8 ft long increase one pipe size over that shown in Table 7. Copyright i American Society of Heating and Ventilating Engineers j Not to be.Reprinted With* 9 (. Heating, Piping and Air Conditioning Contractor* National Association ) out Special Permission 307