ARI Armaturen STEVI 426 EN - Manual (Page 13)

Rev. 0040314001 0410 Page 13
Operating and installation instructions
Straight through control valves - STEVI
®
425 / 426
7.2.3 Replacement of the seat ring
Only with bodies (pos. 1) of cast iron the seat ring is screwed in.
- Remove actuator. (Refer to operating instructions for actuator!)
- Loose nuts (pos. 11).
- Detach valve top part.
- Unscrew seat ring (pos. 2) with a special wrench (can be obtained from the manufacturer).
- Clean thread and sealing taper in body (pos. 1) and apply with suitable lubricant.
- Replace respectively recondition seat ring (pos. 2).
- Install seat ring (pos. 2). (For tightening torques refer to item 7.3.2.)
- Replace gasket (pos. 9).
- Assemble valve top part.
- Secure with nuts (pos. 11) and tighten them crosswise.
(For tightening torques refer to item 7.3.1.)
7.3 Tightening torques
7.3.1 Tightening torques for nuts
7.3.2 Tightening torques for seat rings
! Refer to operating instructions for actuator concerned for
installing actuators !
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.
ATTENTION !
Refer to item 10.0 and 11.0 before dismantling the valve.
M 24 = 340 - 410 Nm
M 27 = 340 - 410 Nm
DN 300 = 3850 Nm
-
ATTENTION !
- It is essential that the safety regulations are observed when identifying faults.