4.
MAINTENANCE
4.1
General
Although Metso’s
Jamesbury
valves are designed to
work under severe conditions, proper preventative
maintenance can significantly help to prevent unplanned
downtime and in real terms reduce the total cost of
ownership. Metso recommends inspecting valves at least
every five (5) years. The inspection and maintenance
frequency depends on the actual application and process
condition. Routine maintenance consists of tightening
the lower stem nut (item 16 in Figure 10) periodically to
compensate for stem seal wear.
Overhaul maintenance consists of replacing seats and
seals. A standard repair kit consisting of these parts may be
obtained through your authorized Metso Distributor.
NOTE: Repair kits contain the stem seals for both
fire-tested and non-fire-tested valves, two stem seals (8),
one secondary stem seal (7), and one lower stem seal
(24). The two stem seals (8) are white in color and are
both used for non-fire-tested; one upper and one lower.
The lower stem seal (24) and secondary stem seal (7) are
used for fire-tested valves. The Xtreme® (XT) seated repair
kit contain a black lower stem seal (24). All other kits (TT,
MT, BT, BP) contain a red tinted lower stem seal (24) to
distinguish it from the white upper stem seal (8). If the
lower stem seal (24) is not noticeably different in color
from the upper stem seal (8), the lower stem seal (24) is
always 0.030” (0.76mm) thinner than the upper stem seal
(8). PEEK® seated valves (LG) contain two identical graphite
stem seals (8), one upper and one lower.
Refer to the Repair Kit chart (see Table 3 OR 4).
WARNING:
FOR YOUR SAFETY IT IS IMPORTANT THE FOLLOWING PRECAUTIONS
BE TAKEN PRIOR TO REMOVAL OF THE VALVE FROM THE PIPELINE
OR BEFORE ANY DISASSEMBLY:
1.
WEAR ANY PROTECTIVE CLOTHING OR EQUIPMENT
NORMALLY REQUIRED WHEN WORKING WITH THE FLUID
INVOLVED.
2.
DEPRESSURIZE THE PIPELINE AND CYCLE THE VALVE AS
FOLLOWS:
A. PLACE THE VALVE IN THE OPEN POSITION AND DRAIN
THE PIPELINE.
B.
CYCLE THE VALVE TO RELIEVE RESIDUAL PRESSURE IN THE
BODY CAVITY BEFORE REMOVAL FROM THE PIPELINE.
C.
AFTER REMOVAL AND BEFORE ANY DISASSEMBLY, CYCLE
THE VALVE AGAIN SEVERAL TIMES.
4.2
Actuated Valve
It is generally most convenient to detach the actuator and its
auxiliary devices before removing the valve from the pipeline.
If the valve package is small or if it is difficult to access, it may
be more practical to remove the entire assembly.
NOTE: To ensure proper reassembly, observe the position
of the actuator and positioner/limit switch with respect to
the valve before detaching the actuator.
WARNING:
ALWAYS DISCONNECT THE ACTUATOR FROM ITS POWER SOURCE,
PNEUMATIC, HYDRAULIC OR ELECTRICAL, BEFORE ATTEMPTING TO
REMOVE IT FROM THE VALVE!
WARNING:
DO NOT REMOVE A SPRING-RETURN ACTUATOR UNLESS A
STOP-SCREW IS CARRYING THE SPRING FORCE!
1. Detach the air supply, electrical supply, hydraulic supply
and control signal cables or pipes from their connectors.
2. Unscrew the actuator mounting bracket screws.
3. If the valve assemble has a split no-play (clamped)
coupling, loosen the coupling screws.
4. Lift the actuator straight up in line with the valve stem
until the coupling between actuator drive and valve
stem is completely disengaged.
5. Place actuator in a safe location to avoid damage or
personal injury.
4.3
Manual Valve – with Handle
1. Remove the handle screw (16) and washer (19). Lift the
handle (17) straight up in line with the valve stem until
it is completely disengaged (see Figure 17)
2. Place all disassembled handle parts in small basket or
bag to prevent damage or loss.
4.4
Disassembly
Tools needed to disassemble
Jamesbury
valves may be
ordered from your local Metso Distributor.
NOTE: lf complete disassembly becomes necessary; it is
recommended to replace all seats and seals. Refer to the
Repair Kit chart (see Table 3 or 4).
NOTE: Always use original OEM parts to make sure that the
valve functions properly.
1. Follow the steps in all the WARNING sections above
before performing any work on the valve.
2. Open and close the valve and leave in the closed
position.
3. Unbend the stem nut lock tab (15) and remove the
lower stem nut (16), stem nut lock (15), the compression
ring (21), the upper stem seal (8) and associated
hardware from the top of the stem (4). See Figure 10.
4. Unscrew and remove the insert (2). Remove and discard
body seal (6).
5. Slowly place the valve in the vertical position with the
insert end down on a soft cloth or cardboard. The ball
IMO 4/18
IMO-50 EN
5
