Val-Matic Cam-Centric Plug Valve - Manual (Page 8)

8
PACKING REPLACEMENT: To replace the packing
(7), it is recommended that the line be drained and the
actuator removed. The valve can remain in the line. Te
replace the packing, first open the valve and drain the
line. Close the valve to hold it in position. For power
actuators, turn off and lock out electrical and hydraulic
supplies before proceeding.
Remove the small round cover on actuator to expose
shaft and key. Remove actuator mounting bolts and lift
actuator from valve taking care not to lose square key.
See Figure 12 and remove gland bolts (19) and lift
follower (18) from the valve shaft. Remove old packing
(7) with packing hook. Lubricate new packing with
FDA grease and set in place one ring at a time taking
care not to bend over the lips of the packing rings.
Reinstall follower with 2 shims (29) per bolt (3 shims
for 12” and larger valves). With valve in the closed
position, place the actuator over valve and reinsert key
(24). Finally, reinstall cover on actuator indicating
“Closed”.
PACKING REPLACEMENT WITH ACTUATOR: The
above procedure with removal of the actuator will result
in the most reliable shaft seal. But if the actuator can
not be removed, the following alternate procedure can
be followed. To prevent the possibility of leakage
during this procedure, open valve and drain the line.
Referring to Figure 12, remove follower bolts (19) and
side follower (18) up to actuator. Remove packing
adapters and rings (7) with packing hook. Cut rings
with knife to remove. New packing rings should be cut
at a 45 degree slope to allow insertion around the shaft
and provide some overlap. Install rings one at a time
with the tips down toward the valve. Stagger all joints
180 degrees around the shaft. Pull down follower (18)
and reinsert bolts (19) with 2 shims (29) under follower
(18). V-packing is pressure assisted and only requires
light compression. GEAR ACTUATOR MAINTENANCE: A typical gear
actuator is shown in Figure 13 and consists of a worm
(3) mounted on an input shaft (9). The worm engages
a worm wheel (2). When the worm is turned, it drives
the wheel through 90
 of rotation. The rotation of the
valve plug is displayed by the top indicator (5). The
open and closed positions of the segment gear are
controlled by an end position stop bolts (20). The
stops can be adjusted by loosening the lock nut (21)
and rotating the bolts. The gears are lubricated with
EP2 grease in a cast iron housing (1). Other parts are
listed in Table 5.
The gear box is factory lubricated and sealed. No
regular maintenance is required. If difficult operation is
observed, the cover (4) can be removed and the unit
inspected for wear. All moving parts should be coated
with grease. The grease should have an even and
smooth consistency. If needed, coat all moving parts
with an lithium-based EP-2 grease such as Shell
Alvania #2 or equal. Buried units should be packed
90% with grease.
FIGURE 13. GEAR ACTUATOR CONSTRUCTION
CAUTION: Drain line and close valve before
removing actuator or valve may
rotate suddenly. Take precautions
against exposure to toxic or
hazardous fluids in the line.
CAUTION: If packing assembly contains
clamp style follower as shown in
Figure 8, do not lubricate shaft or
sleeve.
CAUTION: Take precautions against
exposure to toxic or hazardous
fluids in the line.