Document 06YOVNLn0nndpnQpyVjKwbvmb

764 CHAPTER 55 1960 Guide nraina as affected by bacteria (New England Water Works As sociation Journal, Vol. 46, No. 42). " R. F. Hadley: Microbiological anaerobic corrosion of steel pipe lines (The Oil end Cos Journal, September 1939). 17S. T. Powell: Cold water vacuum deaeration (Water Con ference Proceedings, Engineers' Society of Western Pennsyl vania, 1945, p. 51). UG. B. Hatch and Owen Bice: Corrosion control with threshold treatment (Industrial and Engineering Chemistry, VoL 32,1940, p. 1672). " J. H. Wilson and E. C. Groesback: Tests of corrosion in hibitors for water treatment in air conditioning equipment (National Bureau of Standards Journal of Research, VoL 24, 1940, p. 665). "C. M. Sterne: The control of corrosion in air-conditioning equipment by chemical methods (American Society for Testing jfatertoie Proceedings, Vol. 38,1935, Part 2, p. 261). 11 Sidney Sussman and J. B. Pullman: Corrosion in closed recirculating water systems (Healing and Ventilating, October 1953, p. 77). "F. N. Speller: Corrosion--Causes and Prevention (MoGraw-Hill Book Co, New York, 1951, pp. 805, 905, 910, 912). Rolf Eliassen, R. T. Skrinde, and W. B. Davis: Experi mental performance of miracle water conditioners (American Water Works Association Journal, Vol. 50, No. 10, October 1958). **J. F. Keville and M. A. Scicchitano: Your stake in water conditioning (Refrigeration and Air Conditioning Business, Oc tober 1958). "L. F. Collins: Engineering problems of water treatment (Power Plant Engineering, July 1946, pp. 78, 120). * Corrosion and its Prevention (Air-Conditioning and Re frigeration Institute, Washington, D. C, 1958). "J. J. McNeil: Rubber linings and coatings (Corrosion and Material Protection, March-April 1947). "J. V. Schaefer: Protection of steel bins from corrosion (Power Plant Engineering, Vol. 28,1922, p. 632). " E. R. Walters: Some Notes on Corrosion of Cast-Iron Sectional Boilers (The Institution of Heating and Ventilating Engineers, preprint, 1944). " See p. 67 of Reference 2. * K. H. Logan and M. Romanoff: Soil corrosion studies, 1941 (National Bureau of Standards Journal of Research, Vol. 33, 1944, p. 145). " L. P. Sudrabin: Cathodic protection of steel equipment submerged in water (Water Conference Proceedings, Engineers' Society of Western Pennsylvania, 1944). "D. W. Hasting: A discussion. (See p. 66 of Reference 14.) MT. 8. Carswell and H. L. Morrill: Cyclohexytamine and dicydohexylamine (industrial and Engineering Chemistry, Vol. 29, 1937, p. 1247). "Drinking Water Standards, etc. (Public Health Reports, Vol. 58, No. 3, Reprint No. 2440, January 15,1943). **R. M. Palmer: Discussion (Heating and Ventilating, Oc tober 1953). * Official Plumbing Code of the City of Detroit, Article V. "Private Communication from H. S. Jordan, AWWA. CHAPTER 56 WATER SERVICES Sizing Cold Water Supply Piping, Procedure for Sizing CoId Water System*, Cooling Wafer Piping, Estimating Heating Load and Storage Capacity, Methods of Heating Water, Direct-Fired, Electric, and Indirect Water Heaters, Computing Heat Transfer Surface, Hot Water Supply Piping, Control of Service Wafer Temperature, Safety Devices, Solar Water Heaters, Domestic Hot Water by Heat Pump PROPER design of the water distributing system in a types of fixtures, and the average pressure necessary to give building is necessary in order that the various fixtures this rate of flow. The pressure necessarily varies with fixture may function properly. The amount of either hot or colddesign, a much greater pressure being necessary with some water used in any building is variable, depending on the type fixtures to give the same rate of flow as in others.- In general, of structure, usage, occupancy, and rime of day. It is neces the lower the quality of the faucet the greater will be the sary to provide piping, water heating, and storage facilities pressure required. of sufficient capacity to meet the peak demand without In estimating the load, the rate of flow is frequently com wasteful excess in either piping or equivalent cost. puted in fixture units. One fixture unit is equivalent to 75 SIZING COLD WATER SUPPLY PIPING gal per min. Table 2 gives' the demand weights in terms-of fixture units for different plumbing fixtures under-several One of the important items that must be determined before any part of the water-piping system can be sized, is the probable rate of flow in any particular section of piping. The rate of flow in the service line, risers, and main branches, however, will rarely be equal to the sum of the rates of flow of all connected fixtures. In fact, the probability that every fixture in a large group will be in use at the same rime is so remote that it would be very poor engineering practice to design the piping to take care of such simultaneous flow. The demand load in building water supply systems cannot be determined exactly and is not readily standardized. The two main problems to be considered are: (1) the satisfactory supply of water for a given fixture, and (2) the number of fixtures which may be assumed to be in use at the same time. The minimum flow that will be satisfactory to the con sumer depends greatly on the consumer, his standard of liv ing, his professional needs, size of family, garden require ments, and similar factors. Depending on these factors, the per capita water ednsumptionfor domestic use usually varies conditions of service, and Fig. 1 gives the estimated demand in gallons per minute corresponding to any total number of fixture units. Fig. 2 shows an enlargement of Fig. i for a range up to 250 fixture units. The estimated demand load for fixtures used intermittently on any supply pipe will be obtained by multiplying the num ber of each kind of fixture supplied through that pipe by its weight from Table 2, adding the products, and then referring to the appropriate curve o! Figs. 1 or 2 to find the demand corresponding to the total fixture units. In using this method it should be noted that the demand for fixture or supply out lets other than those listed in the table of fixture units is not yet included in the estimate. The demands for outlets (such as hose connections, air-conditioning apparatus, etc.) which are likely to impose continuous demand during times of heavy use of the weighted fixtures, should be estimated sepa rately and added to the demand for fixtures used intermit tently, in order to estimate the total demand. So far, the information presented makes posable the de- between 20 and 80 gal per day. Experience indicates that the type of dwelling also has considerable influence on the water consumption. In apartment houses the per capita daily water consump Table 1.... Proper Row and Pressure Required During How for Different. Fixtures tion is generally higher than in single-family houses. This is due to the use of a central metering system which is not con ducive to the saving of water, and to the long hot water lines Fixture flour Pressure? . flow gpa which cause high beat losses and an increase in the wasting of the cooled water. In designing water supply systems for apartment houses, a daily per capita water consumption of 75 gal may be considered a safe design figure. Ordinary basin faucet................................ 8elf-closing basin faucet... /................... Sink faucet--in...................................... Sink faucet--H in....................................... 8 12 10 5 3.0 2.5 4.5 4.5 Although a considerable number of housing projects have Bathtub faucet........................................... 5 6.0 been developed throughout the United States, conclusive Laundry tub cock--% in..... .................... 5 5.0 water consumption data have not been gathered. The daily per capita water consumption in housing projects apparently Ball-cock for closet.................................... 15 3.0 falls in between the consumption in apartment bouses and that in single dwellings at the same geographical location. In general, a daily per capita water consumption of 70 gal Flush valve for closet................................ Flush valve for urinal ............................. Garden hose, 50 ft, and sill cock........ 10-20 15 30 1&-40* 15.0 5.0 can be used as a safe design figure for housing projects. This is indicated by New York City housing project records. Table 1 gives the rate of flow desirable for many common * Flow {Jwme is the Piemue p*5g in tbe pipe t the entrance to the per:ular fixture eaneidered- b Wide range due to vefieticn in deggnend type cf fineh-Telredoeete. 765