Document ZJaER6rNZGDDdOGLN6LVEBL6O
American Society of Heating and Ventilating Engineers Guide, 1930
1. Direct-acting reciprocating steam-driven return-line vacuum pumps. 2. Reciprocating power-driven return-line vacuum pumps. 3. Motor-driven return-line vacuum pumps of the centrifugal or rotary type having one of the following arrangements:
() One pumping unit and motor for handling both air and condensate. () One pumping unit and motor for handling air and a separate pumping unit
and motor for handling condensate.
Table 8. Duplex Piston Type Steam-Driven Pump and Receivers SO lb. Pressure
Size or Pump
Inches
Size or Receiver
Inches
Square Feet or Direct Radiation
Steam
Pipe Sizes, Inches
Exhaust
Suction -
Discharge
3 x2 x3 4Kx 2% x 4 514 x 3Kx 5 6 x4 x6
12x23 12x23 16x32 16x32
5,000
10,000 20,000 40,000
% iK i
Vs K IK lK
IK 2 2K 3
7 x 4Kx8 -20x43
60,000
IK
ik
4
8 x 5 x 10 24x46
90,000
ik
2
4
Size or Pump
Inches
10 lb. Pressure
Size or Receiver
Inches
Square Feet or Direct Radiation
Steam
Pipe Sizes, Inches
Exhaust
Suction
i
IK = IK
2
3 3
'
Discharge
4K x 2 x 4
5K x 2Kx 5 6 x2Kx6
12x23 12x23 16x32
6,000 9,000 16,000
K
l
l
H
IK IK
2 2K 3
IK IK 2
7 x 3 x 8 16 x 32
25,000
IK
IK
4
3
8 x3Kx10 20x43
45,000
IK
2
4
3
10 x4Kx!0 24x46
70,000
2
2K 5
4
Table 9. Characteristics op Centrifugal Return Pumps and Receivers Delivering Against Various Pressures
Rating Square Feet
Equivalent Cast Iron
Direct Radiation
Actual Measured
Water . Capacity
Gallons
per Minute
Motor Horsepowers Discharge Pressure, Pounds per Square Inch at Pump
10 tb.
20 tb.
30 lb.
40 (b.
SO lb.
60 tb.
2,000
4,000
6,000
8,000
10,000
12,000
16,000 26,000 40,000 65,000
100,000
150,000
4
6
8
11
13 16
22
35 60 90 150
200
K K %i 1 2
K K Ki 1 2
K K Ki
IK 2
K K Vt. i
IK 2
K K Hi
IK 2
K Kl
IK IK
K Kl
IK IK
Kl IK 2
IK 3
35
5 7K 7K 10
IK 3 5 5 7K 10
2
5
7K 7K 10
15
3 5 7K 10 15 15
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Chapter 19--Pumps and Traps
(c) One pumping unit and motor for handling condensate with an air ejector operated by a recirculated portion of the condensate for handling the air.
(d) One pumping unit for handling condensate and another for handling the air, both operated by one motor.
The volumetric displacement rate of the water cylinders of steam or power-driven reciprocating return-line vacuum pumps should be from 8 to 10 times the volumetric rate of flow of the condensate to be handled.
The piston speed in feet per minute of steam reciprocating return-line vacuum pumps should not be more than 20 times the square root of the number of inches in the length of stroke.
The speed of crank shafts of power-driven reciprocating return-line vacuum pumps should.not exceed the following:
Length or Stroke Inches
3 6 8 12 20
Maximum Crank Shaft Speed
R.P. M.
80 50 50 40 25
The type of drive to be employed between motor and pump may be chain, belt or gear. When gears are used they should be of a type which will be quiet in operation.
The receiving tank may be placed either on the suction or on the dis charge side of the pump; generally on the suction side.
The capacity of receiving tanks, when placed on the suction side of pumps, should be proportioned to the operating condition to be met. To this end its capacity should be such as to retain the. condensate and to take care of fluctuations between the rate of returning condensate and the rate of the pump delivery. This capacity in case of automatically controlled units should be the capacity of the tank in gallons between the high and low water levels in the tank, as determined by the water-line control, and when not otherwise provided for, should be in accordance with Table 10.
Table 10. Receiver Tank Capacities for Centrifugal orRotary Vacuum Heating Pumps
Square Feet Equivalent Direct Cast IrOn Radiation
Total Receiver Tank Capacitt
in Gallons
Receiver Tank Capacity between High and
Low Water Limits Where Automatic
Water Line Control Is Used
2,500 5,000 8,000 16,000 26,000 40,000 65,000 100,000
6 6 28 33 47 55 69 80
6 6 20 27 34 44 54 63
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