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8. MAINTENANCE
To prevent leakage (internal and external) or malfunction
due to the wear and seals degradation, the final user
must establish a preventive maintenance and inspection
program.
The program shall consider two type of operations:
-Maintenance without disassembly;
-Maintenance with disassembly;
Frequency of maintenance depends on fluid quality,
environment conditions and system working conditions.
8.1. Maintenance without disassembly
This type of maintenance does not require the
disassembly of the valve from the line and can be done
as routine maintenance. This shall include at least:
-Walk around: visually check that everything
goes right, valve is in their normal position, no
vibrations occur, place is clean and nothing
hinders the valve operation;
-External leak check: inspect the equipment to
locate possible leaks
-External coating check: inspect the coating to
prevent rust formation, peeling and any type of
damage on coating;
-Complete stroke: open and close the valve’s
handles (balls and needles) to make sure they
are not stuck;
-Loose check: check tightening of levers and all
the threaded connections to avoid loosening of
equipment;
If a leak is detected on the stem during the check, tighten
the gland nut about a 1⁄6 -turn as a routine maintenance
procedure. This will compensate for any wear or settling
of the gland packing. Excessing tightening of stem nut
can result in high valve operating torque.
8.2. Maintenance with disassembly
WARNING
Disassembly of the valve during the warranty
period determines the end of the warranty
This type of maintenance require the disassembly of the
valve from the process line.
-Internal check: Inspection of parts to detect loss
of wall thickness which may result in decreased
pressure capacity. Check for internal wear of
the valve bore, flange connection, threaded
connections, ball, stem etc.;
-Seals replacement: replace seals and seats of
the complete valve for proper operation;
We suggest the use of WIKA Instruments original spare
parts kit. The kit is composed of: valve seats, soft rings
seals, graphite rings, metal seal rings
In addition to repair kits, other spare parts are available
from WIKA, such as: valve balls, stems, glands, bolts,
screws and nuts. Should additional parts be required, it
is recommended that the complete valve is replaced.
9. DISASSEMBLY
During the operation of disassembly it is important to
avoid any damage of the seals surfaces.
Before disassembling the valve from the line it is
suggested to purge the line using inert gas (Nitrogen).
During the purging of the line and then during
depressurization, open the valve at 45° to purge and
depressurize the body cavity.
Prior to servicing the valve, bring it to the open position
making sure to release line pressure and drain all
trapped media in the valve cavity.
It is suggested to place the valve on a work bench and
not on the ground. During the operation be careful not to
introduce foreign bodies or dirt like sand, dust or others.
9.1. Replacement of ball valve flow seals (Fig.1)
1. Unscrew inlet closure fitting (1) or/and unscrew
terminal closure fitting (7);
2. Remove closure gasket ring (2);
3. Remove spacer (3) if any;
4. Remove first seat (4);
5. Set ball in closed position;
6. Remove ball (5);
7. Remove second seat (6)
9.2. Replacement of stem seals (Fig.2)
1. Unscrew stem nut (1);
2. Remove lever (2);
3. Unscrew adjustment stem nut (3)
4. Remove metal gland ring (4)
5. Remove packing ring (5)
6. Remove stem from opened side of the valve, be
careful not to damage the seal surfaces of stem and
closures (7);
7. Remove seal ring (6)
9.3. Replacement of bonnet (Fig.3)
1. Unscrew T-bar internal screw (1);
2. Remove T-bar (2);
3. Remove cap (3);
4. Remove complete bonnet;
WARNING
It is highly recommended to change all the
graphite and metals seals once they have been
dismantled from body.
