Document ypBr3pjrY0ra2LdXx3mb4DNor

American Society of Heating and Ventilating Engineers Guide, 1925-26 132 F ig . 47. V olum e of A ir through Orifices under V acuum American Society o/ Heating and Ventilating Engineers Guide, 1925-26 heaters are to be based upon their equivalent in direct radiation the air capacities for this class of radiation may be- the same as for direct radiation. Table 75. Air Capacities So Ft Direct Equivalent Radiation Surface 8,000 16,000 26,000 40,000 65,000 100,000 150,000 250,000 Diameter Orifice Vac. 10' fi" ft M" A' H" W ft' . rhree }/(zr Air Capacity Cu. Ft. per Min. 5 9. IS 19 34 60 80 180 The air capacity of the pump should be measured at a point in the main vacuum return line just ahead of the vacuum strainer when the pump is operating under the vacuum specified at the pump suction and when handling the quantity of condensate specified at a temperature not exceeding 180 deg. fahr. Air test may be made with water at lower temperatures. This deter mination should be made by means pf a standard test orifice located in an inlet connection to the pump suction and consisting of a plate % of an inch thick with a reamed hole having sharp edges and of a diameter corresponding to the capacity of the pump. The accompanying Fig. 47 may be used , to give the quantity of air handled, corresponding to several sizes of orifices and different degrees of vacuum met with in practice. The water capacity of the pump when operating against 8 in. of mer cury vacuum should be not less than three-tenths (0.3) of a pound of water per hour per square foot pf equivalent cast iron direct radiation based upon condensation at a temperature of not over 180 deg. fahr. when the pump is delivering water against a specified gage pressure at the water discharge of the pump. For pumps handling both air and water' the above water capacity must be delivered, when the pump is main taining a vacuum of 8 in. of mercury and handling.air through a standard orifice corresponding to the air capacity of the pump as herein specified. Commercial pumps are built for 10, 20, 30 and 40 lb, gage pressure at the water discharge of the pump. Table 76. Sizes, Speeds, Horse Powers and Capacities Hytor Electric Motor Driven Condensation Return Pumps Rating in Sq. Ft....................... Discharge Pressure, Lb_____ _ Gallons per Min........................ H. P. Motor.............................. R. P. M. 60 Cycle and D. C.,. R. P. M. 25 Cycle.................... Shipping Weight-- .................. 0 to 2000 10 20 33 H% 1700 1700 1440 1440 330 350 2000-4000 ' . 10 20 66 %M 1700 1700 1440 1440 350 370 4000-8000 10 20 10 10 H . Vi 1700 1700 1440 1440 420 440 8000-16000 10 20 20 20 % H 1700 1700 1440 1440 535 565 133