Gestra ag, Temperature adjustment, Increase in bleed flow – Flowserve CW41 Control Valves User Manual
Page 4: Malfunction
Cooling-Water Control Valves
Gestramat
CW 41, CW 41/4
PN 16, DN 25 – 100 mm (1 – 4")
812993-01/1006cm · 1991 GESTRA AG · Bremen · Printed in Germany
Setting device of CW 41
Read graduation at this edge
Insert key into setting device
until it engages
Temperature Adjustment
GESTRA cooling-water control valves CW 41...– exact
designation see name plate – can be preset with the
adjusting key to the desired cooling-water outlet tem-
perature. The graduations on the key correspond to the
temperatures indicated in the adjustment table.
The required outlet temperature is adjusted after start-up.
Turn adjusting key ¼ to ½ turn at a time. (Remember that
one key can be used for all CWs).
The outlet temperature is indicated by the thermometer.
Note that the reaction period of the plant to an adjusted
temperature might be 10 to 50 minutes.
Increase in Bleed Flow
When supplied, setting screw
7.6 is set so that it does not
touch valve cone
2. To adjust an additional bleed flow with
screw
6 proceed as follows:
1. Turn adjusting key
11 to the left to bring valve cone 2
into closed position. The pressure gauge
15 will then
indicate the full service pressure.
2. Turn setting screw
7.6 to the right until the pressure
gauge indicates a pressure drop which signifies that
the opening point of the valve is reached.
3. Adjust additional bleed flow. Normally, ¼ to ½ turn will
suffice. One complete turn to the right corresponds to
a valve lift of approx. 1.2 mm.
Malfunction
Reasons and Remedies
1. Discontinuous operation, intermittent opening and
closing of valve cone, unstable control position
The reason may be that the cooling-water control
valve is installed at quite a long distance from the heat
exchanger.
Remedy: Install the CW directly downstream of the heat
exchanger or, if this is not possible, increase the bleed
flow.
2. Setting device hard to turn or blocked
This may be caused by foreign bodies, dirt or calcium
deposits in the valve body.
Remedy: Clean cooling-water control valve and mount
a strainer upstream of valve. Calcium deposits can
only be avoided by water softening or possibly a lower
discharge temperature adjustment might help.
3. Cooling-water outlet temperature too high
Possible reasons may be wrong temperature adjust-
ment, deposits in valve body which affect valve lift or
water admission.
Remedy: Check water supply. Check whether valve
cone moves freely by operating setting device of
cooling-water control valve (see also point 2). Check
correct temperature adjustment in accordance with
adjustment table above.
4. Coolling-water outlet temperature too low
This may be caused by wrong temperature adjustment,
deposits in valve body which impair valve lift or too
large a bleed flow.
Remedy: Check whether valve cone moves freely
by operating setting device several times (see also
point 2).
Readjust cooling-water outlet temperature in accord-
ance with adjustment table above.
Check whether bleed flow is not too large. If necessary,
turn setting screw back to reduce bleed flow.
GESTRA AG
P. O. Box 10 54 60, D-28054 Bremen
Münchener Str. 77, D-28215 Bremen
Telephone +49 (0) 421 35 03 - 0, Fax +49 (0) 421 35 03-393
E-Mail [email protected], Internet www.gestra.de
Adjustment table for CW 41 wr, ws, nr, ns, kr, ks
Desired outlet temperature in °C
Corresponding
graduations on
adjusting key
DN 25 mm (1")
DN 40, 50 mm (1½, 2")
DN 80, 100 mm (3, 4")
wr
ws
nr
ns
kr
ks
wr
ws
nr
ns
kr
ks
wr
ws
nr
ns
kr
ks
63
109
74
––––––––––
57
104
69
–––– 22 –––
54
100
65
––––––––––
51
95
60
–––– 20 –––
49
90
55
––––––––––
68
114
79
47
86
51
–––– 18 –––
60
107
72
45
81
48
––––––––––
54
100
65
43
77
42
–––– 16 –––
50
93
58
41
72
37
––––––––––
47
86
51
39
67
32
–––– 14 –––
44
79
44
37
63
27
––––––––––
68
114
79
41
72
37
36
58
23
–––– 12 –––
54
100
65
38
65
30
34
53
18
––––––––––
47
82
51
36
58
23
33
49
14
–––– 10 –––
41
72
37
33
51
16
31
44
0
9
––––––––––
36
58
23
31
44
0
9
30
39
0
4
–––– 8 –––
31
44
0
9
28
37
0
2
27
35
0
0
––––––––––
25
30
–
0
5
25
30
–
0
5
25
30
–
0
5
–––– 6 –––
18
16
–19
20
23
–12
20
25
–10
––––––––––
0
3
–32
16
–19
21
–14
–––– 4 –––
0
9
–26
16
–19
––––––––––
0
3
–32
11
–24
–––– 2 –––
0
7
–28
––––––––––
0
3
–32
–––– 0 –––