Powell Valves - Cv Charts
Flow
Design Recommendations
(1) Swing Check Valves- Minimum 1/2 psi differential
pressure across valve to maintain proper "full
open" position.
(2) Lift Check and Non-Return Valves - Minimum 2 psi
differntial pressure across valve to maintain proper
"full open" positon.
(3) Recommended Maximum Flow Velocities (Approximate)
|
VALVE
SIZE
|
WATER
(FT/MIN)
|
SATURATED
STEAM
(FT/MIN)
|
SUPERHEATED
STEAM
(FT/MIN)
|
|
3"
and UNDER
|
1200
|
7200
|
9000
|
|
4
|
1200
|
8800
|
11000
|
|
6
|
1620
|
10400
|
13000
|
|
8
|
1860
|
12000
|
15000
|
|
10
|
2100
|
14400
|
18000
|
|
12
|
2220
|
15200
|
19000
|
|
14
|
2400
|
16000
|
20000
|
|
16
|
2400
|
17600
|
22000
|
|
18
|
2400
|
19200
|
24000
|
|
20"
and LARGER
|
2400
|
20800
|
26000
|
Flow
Coefficient (Cv) Valves
Carbon Steel
|
|
GATE
|
GLOBE
|
CHECK
(1)
|
|
CLASS
|
150
|
300
|
150
|
300
|
150
|
300
|
|
FIG.
NO.
|
1503
|
3003
|
1531
|
3031
|
1561
|
3061
|
|
VALVE
SIZE
|
|
|
|
|
|
|
|
2
|
240
|
240
|
40
|
40
|
75
|
75
|
|
2-1/2
|
390
|
390
|
65
|
65
|
120
|
120
|
|
3
|
560
|
560
|
95
|
95
|
170
|
170
|
|
4
|
1020
|
1020
|
175
|
175
|
315
|
315
|
|
6
|
2440
|
2440
|
410
|
410
|
760
|
760
|
|
8
|
4500
|
4500
|
760
|
760
|
1390
|
1390
|
|
10
|
6900
|
6900
|
1190
|
1190
|
2170
|
2170
|
|
12
|
10400
|
10400
|
1780
|
1780
|
3250
|
3250
|
Corrosion Resistant Steel
|
|
GATE
|
GLOBE
|
CHECK
(1)
|
|
CLASS
|
150/200
|
300
|
150/200
|
300
|
150/200
|
300
|
|
FIG.
NO.
|
2490/2491
2494/2495
2456
|
2466/2467
|
2474/2475
2629
|
2446/2447
|
2341/2342
2633
|
2345/2346
|
|
VALVE
SIZE
|
|
2
|
240
|
240
|
40
|
40
|
75
|
75
|
|
2-1/2
|
350
|
350
|
65
|
65
|
120
|
120
|
|
3
|
510
|
510
|
95
|
95
|
170
|
170
|
|
4
|
960
|
960
|
175
|
175
|
315
|
315
|
|
6
|
2340
|
2340
|
410
|
410
|
760
|
760
|
|
8
|
4500
|
4500
|
760
|
760
|
1390
|
1390
|
|
10
|
6900
|
6900
|
1190
|
1190
|
2170
|
2170
|
|
12
|
10400
|
10400
|
1780
|
1780
|
3250
|
3250
|
NOTES: 1. 5 DEG. SWING CHECK VALVES
