4
KEYSTONE
FIGURE 79 PNEUMATIC ACTUATOR
OPERATING AND MAINTENANCE INSTRUCTIONS
ASSEMBLY - DOUBLE ACTING UNITS
Note:
Please refer to the relevant exploded
views further on.
Liberally grease actuator bore, pistons and
pinion assembly with Molyrace LT lubricant.
1. Coat all ‘O’-ring seals with Molyrace LT
lubricant.
2. Output shaft assembly:-
a) Fit the top bearing assembly (item 9) into
the top bore of the actuator body (item 1)
with the outer o-ring uppermost.
b) Fit the bottom bearing assembly (item 6)
on to the bottom of the pinion shaft (item
5) with internal o-ring uppermost.
3. Insert pinion shaft assembly from underside
of the actuator as shown in fig. 4.
4. Fit internal circlip (item 12) to bottom recess
of body to locate the shaft assembly.
5. Fit ‘O’-ring seals (item 13) on pistons (item 2).
6. Orientate output shaft at 45° ± 2°.
7. Insert pistons (item 2) complete with
backing pads(1) (item 18) and backing rings
(5), with piston legs on left side of bore
(when viewed from the o-ring end of the
piston), until racks engages with pinion and
then push fully inward, the actuator is now
in the fully closed position.
* If no travel stops are fitted proceed to
instruction 12.
8. Turn the pinion shaft anti-clockwise
approximately 5° until it is orientated in line
with the major axis of the actuator body. The
shaft is now in the closed position.
9. Insert CLOSE travel stop bolt (item 19/20)
together with sealing nut or lock nut (2)(3),
flat washer (2)(3) and sealing washer (2)(3)
NOTES
1 Backing pads are not required on 002/003 models
which have nylon pistons.
2 Lock nuts, flat washers and sealing washers are
only fitted to models 065-180.
3 On models 003/036 the lock nut & sealing nut are
one item.
4 Gear shim is required on models 006 and 012 only.
5 Backing rings and pads are only fitted to models
065/090/180.
Note:
Backing pads and rings need only a smear of
grease on the undersides before fitting to pistons.
Viewed from top of actuator
FIGURE 3
Camshaft
Open position
Flat washer
(Models 065 to 180)
Sealing washer
(Models 065 to 180)
Close position
Camshaft
Actuator body
Close adjustment bolt
Open adjustment bolt
Locking nut
(Models 065 to 180)
Actuator body
until the bolt hits the travel stop cam. Tighten
the lock nut.
10. Turn the pinion shaft anti-clockwise through
90° to bring it in line with the center line of
the actuator bore, the actuator is now in the
open position.
11. Insert Open travel stop bolt (item 19/20)
(together with sealing nut or lock nut (2)
(3), flat washer (2)(3) and sealing washer (2)
(3)) until the bolt hits the travel stop cam.
Tighten the lock nut.
12. Fit ‘O’-ring seals (item 14) to endcaps (item 3)
using a light smear of grease.
13. Fit endcaps to body and alternately tighten
the endcap screws (item 15) until secure
(see recommended torque table).
14. Fit position indicator to top of actuator.
15. Operate the actuator to OPEN & CLOSE
positions using compressed air and note the
actual positions. If the required travel is not
achieved refer to page 12.
