Document e7yVrEpZXdK86jEqddege5GJm

American Society of Heating and Ventilating Engineers Guide, 1928 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. 146 Chapter VI PIPING FOR WATER SUPPLY SYSTEMS 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 1. Table 1. 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 Mih.................................. : 8 16 24 48 60 80 96 128 150 Tanks Pipe Size............................................. ...... X X l IX IX m 2 2 2 Gal. per Min--............................. ; 30 50 80 120 140 160 200 250 300 Flush . Pipe Size...... ............................................. 1 m IX 2 2 2 2X 2X 2X Valves Urinals-- x Gal. per Min........................................ 6 12 20 32 42 56 72 90 120 Tanks Pipe Size.................................................... X 1 IX IX l IK 2 2 Gal. per Min........................................ 25 37 45 75 85 100 125 150 175 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............... 1................................... X X X 1 IX IX IX IX Bath Tubs-- Gal. per Min......................................... . 15 30 40 80 96 112 144 192 240 Pipe Size.............................1................... % 1 IX IX 2 2 2 2X 2X Shower Baths-- xGal. ner Min. 8 Pipe Size........................... ........................ 16 32 64 X IX IX 96 128 192 256 320 8" rain 2 2 2X 2X 3 Head Acid and Slop Sinks, Manufacturing, Kitchen and Laundry-- Gal. per Min......................... ...... .......... _ 15 25 40 64 84 96 120 150 200 per bibb Pipe Size............. X IX m IX 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. 0 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 lb. perisq. in. per 100 ft. of pipe. The total pressure needed to discharge a given Materia! for this section furnished for The Guide by W.'S. Timnils, consulting engineer. New York. 147 '