Publicidad
Idiomas disponibles
Idiomas disponibles
Size
Bolt strength class (lubrication conversion factor 0,86)
8.8
8 (6)
M6
21 (15)
M8
40 (30)
M10
70 (51)
M12
169 (125)
M16
M20
331 (244)
M24
572 (422)
M27
827 (610)
M30
1127 (831)
M33
1522 (1123)
M36
1961 (1446)
7.4 Troubleshooting
PROBLEM
Valve leaks into the
environment.
Leakage or flow through the
valve when valve should be
closed.
Shorter lifetime of the sleeve
than before.
Sleeve is flapping and/or flow
capacity is not sufficient.
In case you cannot find the solution to your problem in the above table, please turn to the nearest Valve Flow Control Oy
representative. The serial number and type identification of the valve in question will help getting the prompt answer.
4PV70EN - 5/2023
Table 3.
General tightening torques for screws
Tightening torques
Nm (ft-lbs) ±5%
MoS2
A4-80
8 (6)
19 (14)
38 (28)
65 (48)
161 (119)
313 (231)
541 (399)
782 (577)
1067 (787)
1437 (1060)
1858 (1370)
POSSIBLE REASON
1. Sleeve breakage.
2. End flanges loosely tightened.
Sleeve breakage.
Sleeve is not closed with sufficient squeeze.
Wrong adjustment of the sleeve.
Sleeve is not closed with sufficient squeeze.
Wrong adjustment of the sleeve.
1. Pneum. valves: wrong adjustment of
the end cushioning in front end-block of
cylinder.
2. Wrong adjustment of the pneum. spring.
Changes in customer process e.g.
composition of medium / temperature
flow capacity
Vacuum or pressure shocks in pipeline,
rubber has hardened and does not open
totally.
ACTION
1. Change and make adjustment of sleeve
2. Tighten the flange end screws
(models PVE, PVS): check by the plug - change and make
adjustment of sleeve
Manual valves - turn the hand wheel more tight.
Pneumatic and hydraulic. actuators - check the supply
pressure for cylinder; if the pressure is too low, the sufficient
squeeze for the sleeve cannot be reached. Check the
compactness of the cylinder seals.
Make the adjustment
Manual valves - turn the hand wheel more tight.
Pneumatic and hydraulic actuators - check the supply
pressure for cylinder; if the pressure is too low, the sufficient
squeeze for the sleeve cannot be reached. Check the
compactness of the cylinder sealings.
Make the adjustment.
1. End cushioning in front end-block of cylinder should be
fully open.
2. Check adjustment of pneumatic spring .
Check the best rubber quality with Valmet Flow Control Oy.
Select another valve size with Valmet Flow Control Oy
(particularly valves with positioners).
Check that the opening tags are fixed.
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