Technical manual
Sylax
DN
25-350 mm
uksylax25_350 - Updated 20/09/2016
12
Flow rate (Kv)
The butterfly valve is not the best product for regula-
ting Nevertheless, the Sylax 25-350 mm butterfly valve
can be used to regulate by an opening stage between
30° and 90°.
A regulation in the opening stage lower than 30° is
not advisable because of over speed, cavitation effect,
which could damage prematurely the valve.
Kv = volume of water in m
3
/h through a valve at a preset
opening stage and under a head loss of 1 bar.
The maximum flow velocity of the fluid through the valve must not exceed :
- 3 m/s for liquid fluids. Between 3 and 5m/s, the use of the Sylax 25-350 mm butterfly valve is possible, but the phenomena
of cavitation, noise, vibration and water hammering increase.
- 20m/s for gas. Between 20 and 25m/s, the use of the Sylax 25-350 mm butterfly valve is possible, but the phenomena of
cavitation, noise, vibration and water hammering increase.
- for pulverulent or paste fluids : please consult us.
OPENING STAGES
OPENING STAGE - Stainless steel disc
DN
10°
20°
30°
40°
50°
60°
70°
80°
90°
25
-
-
-
3
8
16
27
35
40
32/40
-
-
-
5
12
25
40
56
62
50
-
-
1
8
18
33
54
71
79
65
-
-
6
19
41
76
118 158 174
80
-
3
18
43
79 138 211 252 275
100
-
15
38
83 154 253 368 458 496
125
-
20
61 134 249 399 599 792 883
150
5
37 100 200 374 600 863 1109 1212
200
15
76 200 399 680 1099 1666 2196 2500
250
40
150 333 621 1084 1765 2452 3517 3948
300
60
219 500 989 1736 2770 4097 5118 5635
350 145 420 882 1676 2850 4462 6000 7431 8520
DEGRES D'OUVERTURE
DN
0
ϒ
10
ϒ
30
ϒ
20
ϒ
60
ϒ
70
ϒ
50
ϒ
40
ϒ
90
ϒ
80
ϒ
Kv
8
6
5
4
3
2.5
2
1.5
10
1
100
15
20
25
30
40
50
60
80
800
600
500
400
300
250
200
150
1000
10000
1500
2000
2500
3000
4000
5000
6000
8000
8000
6000
5000
4000
3000
2500
2000
1500
10000
1000
150
200
250
300
400
500
600
800
80
60
50
40
30
25
20
15
100
10
4
5
6
8
1500
2000
2500
3000
4000
GALLON/MIN
M3/H
125
200
250
300
65
50
100
80
150
350
32/40
25
