Document 1QwR0EogDJwqYM3OLnrEVeNQK
American Society of Heating and Ventilating Engineers Guide, 1928
Chapter IX--Pumps for Heating and Ventilating Equipment
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 13. Air Capacities
Sq. Ft. Direct Equivalent Radiation Surface
Diameter Orifice Vac. 10'
Air Capacity
Cu. Ft. per Min.
8,000
'of"
5
16,000
A"
9
26,000
K"
15
40,000
A"
19
65,000
W
34
100,000
W
60
150,000
A'
80
250,000
Three W
180
*
.
F ig . 8. V o lu m e of A ir th r ou gHjO r ific b s under V ac u u m
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 of a standard test orifice located in an inlet connection to the pump suction and consisting of a plate J/g 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. 8 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 of 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 14. Sizes, Speeds, Horse Powers and Capacities Motor Driven Condensation Return Pumps
Rating in Sq. Ft....................... 0-2000
2000-4000 4000-8000 8000-16000
Discharge Pressure, Lb- _ . 10 20
10 . . 20
10 20
10 20
Gallons per Min........................ 3
3
6 6 10 10 20 20
H. P. Motor............................... % H ' Vs %
%H
HH
R. P. M. 60 Cycle and D. C... 1700 1700 1700 1700 1700 1700 1700 1700
R. P. M. 25 Cycle............... . 1440 1440 1440 1440 1440 1440 1440 1440
'J Shipping Weight........................ 330 350 350 370 420 440 535 565 188
189