ARI Armaturen STEVI AS 350 DN15-50 EN - Manual (Page 9)

Rev. 0040322000 3413 Page 2-9
Operating and installation instructions
Y-pattern processing valve - STEVI
®
AS 350
6.0 Putting the valve into operation
7.0 Care and maintenance
Maintenance and maintenance intervals have to be defined by the operator according to
the service conditions.
7.1 Replacement of bonnet
At leakages at the stem or in the plug tightness or resp. on failures of the actuator, the
bonnet must be changed.
Fig. 12
- Relieve valve seat before removing and installing
Function:
Spring closes on air failure (NC) --> switch actuator (switch on air supply pressure);
Spring opens on air failure (NO) --> switch off air supply pressure;
Double acting (DA) --> switch off air supply pressure
- Unscrew bonnet (pos. 2) from the body (pos. 1) (at the hood above the body)
- Remove the gasket (Pos. 3) between body (Pos. 1) and bonnet (Pos. 2) from the body
(Pos. 1).
- Replace gasket (Pos. 3) and screw new bonnet (Pos. 2) into the body (Pos. 1).
(For tightening torques refer to item 7.2).
ATTENTION !
- Before putting the valve into operation, check material, pressure, temperature
and direction of flow.
- Regional safety instructions must be adhered to.
- Residues in piping and valves (dirt, weld beads, etc.) inevitably lead to leakage.
- Touching the valve when it is operating at high (> 50 °C) or low (< 0 °C) media
temperatures can cause injury.
Affix warning notice or protective insulation as appropriate!
Before putting a new plant into operation or restarting a plant after repairs or
modification, always make sure that:
- All works has been completed!
- The valve is in the correct position for its function.
- Safety devices have been attached.
- Control lines are mounted relaxed and without kinkings.
ATTENTION !
Refer to item 10.0 and 11.0 before
dismantling the valve.