12
Watson McDaniel Company
PMPNT Manual 2605100 Rev A
Vented Receiver Sizing
Vented Receiver Sizing
Flash Steam
up to --
Receiver
Vent Line
Dia.
Dia.
Length
75 pph
4”
36”
1”
150 pph
6”
36”
2”
300 pph
8”
36”
3”
600 pph
10”
36”
4”
900 pph
12”
36”
6”
1200 pph
16”
36”
6”
Below figures are approximate for 4” X 4”
Packages
2000 pph
20”
60”
8”
3000 pph
24”
60”
8”
4000 pph
26”
60”
10”
5000 pph
28”
60”
10”
6000 pph
30”
72”
12”
7000 pph
32”
72”
12”
8000 pph
36”
72”
14”
When sizing a Pressure Motive Pump for an
atmospheric return system, the amount of flash
steam to be vented through the receiver must be
calculated. Vent sizing is critical to maintain zero
psig in the receiver tank to allow free drainage of
low pressure systems. Undersized vents will cause
gradual pressure increase in the receiver. This
impedes drainage from the condensate source, and
can cause water logging of the system.
To Size Receiver & Vent:
Usually the condensate load to be pumped comes
from multiple sources. For each source determine
the pressure and load. Then go into the "Percent
Flash" table with the condensate pressure and
move right until under the appropriate tank
pressure to read the percentage of condensate
that will flash into steam. Now take that source
load and multiply it by the decimal value of the
percentage to calculate the amount (lbs/hr) of
flash steam. Repeat this for all condensate
sources and total the flash steam. Enter the
"Vented Receiver Sizing" table with the total flash
steam load to determine the correct sizes for
receiver and vent.
Percent Flash Steam
Condensate
Pressure
(PSIG)
Flash Tank Pressure (PSIG)
0
2
5
10
15
20
30
40
60
80 100
5
1.6 0.9
0
10
2.9 2.2 1.3
0
15
3.9 3.3 2.4 1.1
0
20
4.9 4.2 3.3 2.1
1
0
30
6.5 5.8
5
3.7 2.6 1.7
0
40
7.8 7.2 6.3 5.1
4
3
1.4
0
60
10 9.4 8.5 7.3 6.2 5.3 3.7 2.3
0
80
12
11
10 9.1 8.1 7.1 5.5 4.2 1.9
0
100
13
13
12
11 9.6 8.7 7.1 5.8 3.5 1.6
0
125
15
14
14
12
11
10 8.8 7.5 5.3 3.4 1.8
150
16
16
15
14
13
12
10
9
6.8 4.9 3.3
200
19
18
17
16
15
14
13
12 9.4 7.6
6
250
21
20
19
18
17
16
15
14
12 9.8 8.2
300
23
22
21
20
19
18
17
16
13
12
10
350
24
24
23
22
21
20
18
17
15
13
12
400
26
25
24
23
22
21
20
19
17
15
14
