Flowserve NAF-Turnex pneumatic actuators - Manual (Page 8)

8
7. Grease the O-rings (30, 43) and fit the rings into the
cylinders (35).
8. Apply a thin film of grease to the surfaces of the
cylinders (35), and use a piece of clean, lint-free linen
cloth to work the grease into the whole of the sliding
surfaces. Carefully push the cylinders onto the
pistons.
9. Fit the bolts (12), and tighten them in diagonally
opposite pairs to the torque specified in Table 2.
10. Fit the cover (2). Apply some locking compound to the
threads of the bolts (12), and tighten the bolts to the
torque specified in Table 2.
11. Adjust the end stop bolts (38) to the required end
positions.
3. Actuator with spring return
The spring-return actuator is basically a double-acting
actuator in which one of the cylinders has been replaced
by a return spring cylinder. Double-acting actuators can
thus easily be converted to spring-return actuators and
vice versa.
CAUTION
The spring-return cylinder contains one or more
preloaded springs. To avoid the risk of injuries,
handling and dismantling must be carried out in
accordance with the instructions below.
3.1 Conversion of a double-acting actuator
Sizes 0 and 1-3
1. Determine the required operating mode of the spring-
return actuator:
Spring closing/air opening NAF 791292.
Spring opening/air closing NAF 791294.
2. Start with a complete spring-return unit, i.e. items
50 to 62 inclusive and items 3, 5, 6, 8, 9 and 17.
In addition to these items, the spring-return unit also
includes a transport securing plate (61) shown in
Fig. 10. Remove the end stops (8, 9) from the spring-
return unit.
3. Remove the end stops (7, 8, 9) from the actuator
which is to be converted.
4. Depending on the required operating mode of the
converted actuator (see item 1 above), remove the
nuts (6) on the selectedx side in accordance with the
following and Fig. 19.0 and 19.1:
Spring closing/air opening. Side B (791292).
Spring opening/air closing. Side A (791294).
5. Size 0 - When the bolts (2) have been removed, the
cylinder (1 or 16) and the end cover (4) can be
removed.
Sizes 1-3 - When the nuts (6) have been removed, the
cylinder (1 or 16), end cover (4) adn tie rods (2) can
be removed.
6. Remove the piston rod nu (24) and remove the piston
(25) and washer (24.1).
7. Push the projecting end of the piston rod as far as
possible into the housing.
8. Release all nuts (6) on the complete spring assembly,
but do not remove the nuts from the tie rods.
Make sure that the spring assembly does not point
towards any person, since the assembly contains
preloaded springs. Make sure that the spring cylinder is
loose between the transport securing plate (61)
and the end cover (4). Then remove the nuts from the tie
rods (2). Now remove the end cover, plate and tie rods
from the cylinder.
9. Size 0 - Fit the new O-rings (3, 17) onto the piston rod
bearing and fit the new tie rods (54).
Sizes 1-3 - Fit the new O-rings (3, 17) into the
housing and fit the new tie rods (54).
10. Push in the new spring cylinder, so that the air
passage is aligned with the O-rign (17) and so that the
spring piston (50) is against the piston rod.
11. Apply locking compound to the thread of the long
piston nut (56), and tighten the nut to the torque
specified in Table 1.
12. Fit the end cover (59), washers (5) and nuts (6) and
tighten the nuts in diagonally opposite pairs to the
torque specified in Table 1.
13. Fit the end stops (7, 8, 9) and adjust them to the
required end positions.
Size 4
1. Start with a complete spring-return unit, i.e. items
46 to 51 inclusive. Move the end stop (37 -39) from
the cylinder (35) to the spring-return unit.
2. Place the actuator with the cylinder which is to be
replaced so that the spring cylinder points upwards.
3. Remove the bolts (12) and remove the protective
cover (20) or the corresponding cylinder (35). See Fig.
19.4.
4. Inspect the parts as described in section 2.2, and
make sure that the contact surfaces of the spring
cylinder and centre section have been thoroughly
cleaned.
5. Grease and fit the new O-rings (30 and 43).
6. Apply a thin coat of grease to the internal surface of
the spring cylinder, and use a piece of clean, lint-free
linen cloth to work the grease into the whole of the
sliding section.
7. Set the piston (32) in the position nearest to the
centre section.
8. Place the spring assembly (47) on the piston and
check that the guide fits the piston nut (36).
9. Carefully push the spring cylinder over the spring
assembly and onto the piston.
10. Fit the spring cylinder nut sleeves (50) and studs (49).
Tighten them gradually one turn at a time, and tighten
finally to the torque specified in Table 2.
Size 5
1. Start with a double-acting actuator NAF 791290-
51 or -52.
2. Remove the cylinder which is to be replaced by a
spring return cylinder.
3. Remove the piston fitted to the piston rod.
4. Fit the new piston (1) to the piston rod, but do not
tighten the piston rod nut (2). See Fig. 11.