Samson EB 20a, Монтаж и эксплуатация

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12-1
EB 20a_EN
May 2022 edition
Subject to technical changes
Repairs
12 Repairs
If the ball valve no longer works properly or if it does not work at
all, it is defective and must be repaired or replaced.
Damage to the ball valve due to improper maintenance and re-
pair!
Ö
Do not perform maintenance and repair work on your own.
Ö
Contact the After Sales Service at PFEIFFER for maintenance
and repair work.
In special cases, certain maintenance and repair work may be
performed.
The work described in this chapter may only be performed by
specialist personnel quali
fi ed to perform the corresponding task.
The following instructions apply additionally for ball valves. For
decommissioning and disassembly, observe Chapter “10 Decom-
missioning” and Chapter “11 Disassembly”.
Please note when repairing!
In fl uences from the process medium and residues can affect the
torque for body connections when old balls and seals are reused,
see Table 15-1 in Chapter “15.1.1 Tightening torques”.
12.1 Replacing the V-ring packing in the case
of a DIN ball valve
12.1.1 Ball valve in the “standard version”
If a leak is found in the stuf fi ng box (11), the PTFE rings of the
V-ring packing (7) could be defective.
Ö
Check the condition of the V-ring packing.
Disassemble the ball valve to remove the packing. For this pur-
pose, observe Chapter “1 Safety instructions and safety meas-
ures”.
Ö
Place the ball valve on an even and clean work surface so
that the packing space is easy to reach.
Ö
Loosen the screws (12) and remove the stuf fi ng box fl ange
(11) with the bearing bushing (10) carefully.
Ö
Remove the spring washers from the set of spring washers
(9).
Ö
Remove the thrust ring (8).
Ö
Remove the V-ring packing (7).
Ö
Check the PTFE rings of the V-ring packing as well as all
plastic parts for damage and, in the case of doubt, replace
them.
Ö
Assemble the ball valve as described in Chapter “3.5.1 DIN
ball valve assembly”.
NOTE
Info
12.1.2 Ball valve with “double stuf fi ng box”
Leak in the test connection
If a leak is found in the test connection of the stuf fi ng box lower
section (19), the PTFE rings of the V-ring packing (7) could be
defective.
Ö
Check the condition of the V-ring packing.
Disassemble the ball valve to remove the packing. For this pur-
pose, observe Chapter “1 Safety instructions and safety meas-
ures”.
Ö
Place the ball valve on an even and clean work surface so
that the packing space is easy to reach.
The stuf fi ng box upper section is preloaded during assembly. To
prevent it from loosening up uncontrolled, it is secured with an
assembly sleeve during disassembly.
Ö
Push the assembly sleeve over the ball stem up to the stuf fi ng
box upper section (25).
Ö
Screw a nut onto the ball stem (2).
Ö
Undo and remove the screws (26).
Ö
Carefully undo the nut and assembly sleeve and remove
them.
Ö
Carefully remove the stuf fi ng box upper section (25) with the
bearing bushing (10) and the o-ring (24).
Ö
Remove the V-ring packing (23).
Ö
Remove the thrust ring (22).
Ö
Remove the spring washers from the set of spring washers
(21), distance bushing (20) and spring washers from the set
of spring washers (9).
Ö
Remove the thrust ring (8).
Ö
Remove the stuf fi ng box lower section (19) with the o-ring
(18).
Ö
Remove the V-ring packing (7).
Ö
Check the PTFE rings of both V-ring packings as well as all
plastic parts for damage and, in the case of doubt, replace
them.
Ö
Assemble the ball valve as described in Chapter “3.5.1 DIN
ball valve assembly”.
Leak in the stuf fi ng box
If a leak is found in the stuf fi ng box upper section (25), the PTFE
rings of the V-ring packings (7 and 23) could be defective.
Ö
Check the condition of the V-ring packings.
Info