VAG Operation and Maintenance Instructions • 15
• Fasten the gear fixing screws
Picture 16: Replacement of O-ring – Step 5
• If necessary, readjust the limit stop of the gear. The limit stop
must only be adjusted when the valve is in closed position.
AUMA worm gear units are adjusted as specified in the AUMA
90° Gear Operation Manual.
Caution:
For all repair and maintenance work, please observe the
general safety instructions described in Section 7.1!
Problem
Cause
Remedial action
Valve makes noise
Unfavourable installation position
causing unfavourable flow around
or inside the valve (e.g. installed too
closely downstream of an elbow etc.)
Change installation position
Valve operating beyond its design limits
Check design and/or operation data, change flow resistance
in the valve, if required, by using different internals
Valve cannot be operated
Foreign matter jammed in the seat area
Flush valve, dismantle, if necessary, and remove foreign matter
Gear blocked
Undo block
No electrical connection of electric actuator
Establish electrical connection
Unfavourable flow and im-
pairment of movement
Change installation position
Leaks in the body seat
Valve not completely closed yet
Close valve completely
Valve seal damaged or worn
Replace seal
Cavitation in valve
Valve operating beyond its design limits
Butterfly valve not suitable for use as control valve. Re-
place valve by a more suitable valve type.
Operational data changed
Leaks at the body
Deterioration of seals
Replace seals
High operating forces
Seat of the valve polluted by deposits
Flush valve, dismantle, if necessary, and clean seat area
Valve is dry in pipeline, no medium present
Valve can be operated more easily when wet
Head office
VAG-Armaturen GmbH
Carl-Reuther-Str. 1
68305 Mannheim
Germany
Phone: +49 (621) 749-0
Fax: +49 (621) 749-2153
http://www.vag-group.com
Service
Our service hotline can be reached 24/7 world-wide. In case of
emergency, please contact us by phone.
Service hotline: +49 621 - 749 2222
Service per email: [email protected]
8 Trouble-shooting
9 How to contact us
