Document oMaYwpYq2yqoJvXp3pVQk1vo8

American Society of Heating and Ventilating Engineers Guide, 1928 Table 1: Flow of Steam in Pipes f/oiv of Sfetrm //> f'z/oes oss xv fSessse/Br //v os. tos/ae D/am/ts* orP/rr /-v Ab/cmss --Le/vcm or P/bjt //v Prrr Wc/cstr or / Cufr orS/sam SV"Lbs o/r SrorA* /*& M/w P-O.OOO/52 f/ 4 ^LS. ) ( a/ oct^. S^ssst/r. Cot./ A^/rr S/rr A/vrs/e/Mi Cot.2 St/am oss xv AVotf/A/At Ae/uAt . 47A OJT A^rrssy Oz* &7osz: A/srsMAi A7r>e B/GaC* V/oo P/A*t7J*A Soy A/vs 0.23 A033 / A049 0.364 * 0.556 -AO o.so 333 ti A.330 7496 t/70 ** ~o.s Col .3 r a/07 0/90 l SA/Cr/7 or A^/rs /tv 2o 40 Cot.4 I AOO V 2. 2. 24o /.SGo /oo 2/73 /i - / 6/o 2.036 A323 0:0 O. A93 60 A Zfo z 3 076 2 2.067 3.336 5.7/0 0.3 0/75 30 A A20 3 3767 2.46? 4.7BB 6/09 A3 0.20/ AOO AOOO 4 4 3SO 3 3.063 7J?3 A//63 2.3 o zo7 A20 O 9/2 S 4:363 3i 3.540 9007 76 705 S3 0.223 A4o 0,34/ 6 3328 4 4.026 72.730 2363/ AO. 3 0.243 A60 6. 793 7 3.733 4 i 4.S06 A3. 947 32/34 A33 0270 /so 0.74/ 3 6/32 S 3047 20. 006 43.7/9 20.3 0.290 Zoo O. 7/0 to 6/76 6 6.063 2G.&G6 7A76Z 3o.3 0 326 2SO 0.632 A2 7434 7 7023 33. 743 06.273 40.3 0.3SB 300 O.S73 /4 A/36 3 775/ 50027 /49.382 So 3 OJ33 350 0.338 A6 3.7oo 9 3.94/ 62706 20/655 60.3 0.4/3 400 O.SOO ZO 972? AO 0.020 76 334 272.592 743 0.432 430 0.477 24 AO. 6S3 /Z ZB //.SO?' AS. 72.000 AA3.0fa 437.303 A00.3 \ A3.230 A37.3SO 366.6f3 /23.3 O.S07 OSS7 . 300 600 0.4*7 0:407 32 40 ZB 4 /So 320 430 A2 304 A6 75.250 732.651 3/6.672 A30. 3 0.603 .700 ' 0.373 A3 746 /SO69 A94S4 Column 1 X 2 X 3 X 4 = lb. of steam per minute that will flow through a A/S3 straight pipe for a given condition. ZOO. 3 tsxampit.--I oz. drop -- 2 in. pipe .-- 1.3 lb. press. -- 100 ft. equivalent length: 0.643 Goo 0.334 0633 900 -O 333 AOOO O. 3/6 775/2 2.175 X 3.710 X 0.201 X 1 = 1.62191b. per min. 1.6219 X 60 X 4 = 389.3 sq. ft. equivalent radiation. AZOO 0.239 33 9o6 Table 1 does not allow for entrained water in low-pressure steam, condensation in covered pipe and roughness in com 47-652 mercial pipe as found in practice. 300 0.233 20O0 0.224 *1 lb. per sq. in. gage = 2.04 in. Vacuum, Mercury Column. 90 r ' . Chapter III--Steam Heating Systems and Piping hammer or store water in some parts of the system. The velocity "iTvhich such disturbance takes place depends upon the size of the pipe, > location (whether, vertical or horizontal), its pitch and the quantity ofS water flowing counter to the steam. Unusual Conditions IJ der this heading are the character and class of the building, the odicity of use aiid the degree of normal temperature to be attained at the beginning of each period of use. In public buildings, schools, offices, places of assemblage, and such buildings (where the occupants are normally at rest) the building should be heated to its required temperature at the beginning of each period of use In some buildings (especially offices, schools and public buildings), the time between heating periods is relatively short; whereas in others (such as churches, theaters and places of assemblage), these periods are comparatively long. In other buildings, where the occupants are moving about, it is not always necessary for the building to be heated to the required temperature at the beginning of its period of use. In all cases heat given off by machinery, occupants and illumination, also the heat absorbed by the contents of the building should be taken into account. GENERAL DATA ON PIPE SIZE TABLES The following Tables 1 to 20 have been compiled for use in designing all types of steam heating systems, and may be used, by those experienced in the profession, with satisfactory results. The following general principals should be followed: 1. The initial pressure should not exceed 16 oz. gage. 2. It is recommended that the drop in pressure in the mains and riser to the farthest radiator should not exceed 1 oz. per 100 ft. of straight pipe or its equivalent length, with a lower rate of drop for systems with long runs.* 3. In small installations, such as residences, where the longest actual runs is seldom over 200 ft. and where the firing periods extend over several hours, resulting in boiler pressure, fluctuating from zero to about 1 lb., the total pressure drop should not exceed 2 oz. for gravity systems. In large buildings, where boilers are under the constant care of a fireman and a uniform pressure is maintained, and where the water line dif ference will permit, the total drop in pressure may range from 3 to 8 oz. depending upon the equivalent length of the longest run. 4. The total allowable drop in pressure depends upon (a) the water line difference, (6) the equivalent length of main and riser from the boiler to the farthest radiator, and (c) the regularity of the pressure maintained at the boiler or source of steam supply. 5. The water line difference or distance between the water line of the boiler and the low point of steam main and dry return main should be not less than 24 in., because of the heavy drop in pressure from condensation in heating up a cold system. This difference should be increased 2 in. for every ounce pressure drop in the system. If the total pressure drop were 6 oz., the water line difference should be 6. X '2 -|- 24 or 36 In. 6. There should be a nearly uniform drop in pressure between the source of steam supply and the farthest radiator on every riser. Care should be taken however, to see that the maximum allowable velocity for smooth operation is not exceeded. 7. In using this method of proportioning a system, care must be exercised to see that no pipe carrying condensate counter to the steam, is loaded to a capacity above the maximum for the particular part of a system in question as shown in Tables 4,5 and 8 to 16. This rule applies only when the amount of radiation on any riser does not exceed the values in Tables 4 and 5.