ARI Armaturen STEVI AS 350 DN15-50 EN - Manual (Page 10)

Page 2-10 Rev. 0040322000 3413
Operating and installation instructions
Y-pattern processing valve - STEVI
®
AS 350
7.2 Tightening torques
8.0 Troubleshooting
In the event of malfunction or faulty operating performance check that the installation and
adjustment work has been carried out and completed in accordance with these Operating
Instructions.
If malfunctions cannot be eliminate with the help of the following table
“9.0 Troubleshooting table”, the supplier or manufacturer should be consulted.
9.0 Troubleshooting table
DN 15 = 50 Nm
DN 20 = 50 Nm
DN 25 = 60 Nm
DN 32 = 70 Nm
DN 40 = 80 Nm
DN 50 = 100 Nm
-
ATTENTION !
- It is essential that the safety regulations are observed when identifying faults.
ATTENTION !
- read item 10.0 and 11.0 prior to dismantling and repair work!
- read item 6.0 before restarting the plant !
Fault Possible cause Corrective measures
No flow Valve closed. Open valve (using actuator).
Flange covers not removed. Remove flange covers.
Little flow Valve not sufficiently open. Open valve (using actuator).
Dirt sieve clogged. Clean / replace sieve.
Piping system clogged. Check piping system.
Valve stem moves in jerks. PTFE V-ring unit damaged or worn Replace bonnet (pos. 2);
refer to item 7.1
Leakage too high when
valve is closed. Sealing surfaces of plug eroded or
worn. Replace bonnet (pos. 2);
refer to item 7.1
Sealing edge of seating damages or
worn. Replace valve
Seating and/or plug dirty. Clean internals of valve;
Pneumatic actuator not completely
vented; spring force not fully effective. Vent actuator air chamber completely.
Actuator not powerful enough. Install more powerful actuator.