Document dYkLjw4j6nk976J3q67Je70ze

American Society of Heating and Ventilating EngiKeers Guide, 1926-27 of hot water made is overhead, where it is not required, and in order to heat the floor coils from end to end, and it is impossible to heat them evenly from end to end, a little larger fire must be maintained than would be necessary if the coils were in two rows, i.e., going and coming, flows and returns under the benches. ' With gravity hot water heating, boilers should always be in pits. The use of overhead mains never makes up for lack of depth of boiler pit. 98 Chapter VI WATER SUPPLY SYSTEMS AND PIPING THE lack of data upon which to base water pipe sizes for plumbing fixtures, branches and mains is probably due to the great number of variables which enter into their proper determination. 'Plumbing fixtures in common use, having what is known as good water flow, deliver the quantities of water per outlet as given in Table 53. Table 53. Cold Water Branch Supply Sizes for Fixtures and Maximum Flow in Gallons per Minute Number of Fixtures 1 2 4 8 12 16 24 32 40 Water Closets-- Gal. per Min.......................................... 8 16 24 48 60 80 96 128 150 Tanks Pipe Size..................................................... X Gal. per Min.............................................. 30 5X0 IX IX IX 2 2 2 80 120 140 160 200 250 300 Flush Pipe Size ................................................... 1 IX IX 2 2 2 2X 2X 2X Valves Urinals----- Gal. per Min.................. ........................... 6 12 20 32 42 56 72 90 120 Tanks Pipe Size...... ........................................... X X Gal. per Min.............................................; 25 37 1 45 IX 75 IX 85 m 100 IK 125 2 150 2 175 Flush Pipe Size.......................... ........................... 1 IX IX IX IX 2 2 2 2 Valves Lavatories and Wash Sinks---- - Based upon Each Faucet Gal. per Min.............................................. 4 8 12 24 30 40 48 64 75 Pipe Size................................................... . X X X 1 ' 1 m IX IX IX Bath Tubs-- , Gal. per Min.......................................... .. 15 30 40 80 96 112 144 192 240 Pipe Size...................................... ............... X 1 m IX 2 2 2 2X 2X Shower Baths-- Gal. per Min.............................................. 8 16 32 64 96 128 192 256 320 8" rain Pipe Size.................... .................... X X IX IX 2 2 2X 2X 3i Head . Acid and Slop Sinks. Manufacturing, Kitchen and Laundry-- Gal. per Min. 15 25 40 64 . 84 120 150 200 per bibb Pipe Size......................... X 1 IX IX IK 2 2 2 2X per bibb Note.--The above sizes are based upon a pressure drop of 30 lb. per 100 ft. In estimating risers and mains, the number of gallons for W. C. and urinals where flush valves are used are to be as given for tanks. The hot water faucets are to be disregarded when estimating cold water risers and mains. Water flowing in pipes is retarded by friction, the extent of which depends upon the velocity, which is the cause of unsatisfactory service when pipes are too small. The amount of head necessary to overcome this friction is known as the friction head, which is usually expressed in feet. It is also known as pressure drop, usually expressed in lbs. per sq. in. per 100 ft. of pipe. The total pressure needed to discharge a given Material for this section furnished for The Guide by W. S. Timmis, consulting engineer, New York. 99 ;