AIR TORQUE
The 4th Generation
Maintenance
6.2) Disassembly
When disassembly of actuator is required for maintenance, firstly remove
the actuator from the valve. Before performing any disassembly operations
it is important to verify that the actuator is not pressurised. Always use cauti-
on and double check that the ports 2 and 4 are vented and are free from
any accessory and/or device. When the actuator is a spring return unit,
make sure that the actuator is in the failed
position before disassembling.
A) Removal of position indicator (Part No. 19), figure 01:
•Remove cap screw (39) if fitted
•Lift position indicator (19) off shaft, it may be necessary to try gently with
a screwdriver.
B) Removal of stop cap screws (Part No. 02), figure 02:
• Remove both stop cap screws together with nut (04) and washer (03)
• Remove stop screw O-rings (11) and discard if replacing all soft parts.
C) End Caps disassembly (Part No 30 right and 31 left) For model AT 551
to AT 701 the 2 end caps (30) are symmetric, figure 03:
•Remove cap screw (End cap 13) in the sequence shown in the fig- ure 03.
Caution: when disassembling a spring return actuator, the end cap (30
and 31) should be loose after unscrewing end cap bolts (13) 4-5 turns. If
there is still force on the end cap after 4-5 turns of the end cap bolts, this
may indicate a damaged spring cartridge and any further disassem- bly
should be discontinued. Further disassembly of the end caps may result in
injury. Return actuator to AIR TORQUE for further maintenance.
• For spring return actuators, always remove spring cartridge.
• Remove end cap O-rings (14) and discard if replacing all soft components.
D) Pistons disassembly (Part No. 40), figure 04:
•Holding the body (50) in a vice or similar device, rotate the drive shaft (60)
until the pistons (40) are released.
Caution: Air pressure should not be used to remove the pistons from the
body.
•Remove piston ‘O’ rings (16) using a small screwdriver; remove the piston
back (05) and piston head (15) bearings. Discard bearings when
replacing all soft components.
E) Pinion shaft disassembling (Part No 60), figure 05:
•Remove spring clip (18) carefully, using nap-ring pliers, remove external
thrust bearing (08) and thrust washer (10).
•Apply downward force to top of drive shaft (60) until it is partially out of
the bottom of the body when it is possible to remove the octi-cam 01) and
internal thrust bearing (08), then push the pinion (60) completely out of the
bottom of the body. If pinion does not remove freely gently tap the top of
the shaft with a plastic mallet.
•Remove top and bottom pinion bearings (06) and (07) and top and bot-
tom pinion O-rings (21) and (22).
•Discard bearings (06) and (07), internal and external thrust washer (08) and
O-rings (21) and (22) if replacing all soft components.
Via Alla Campagna n.1 * I - 24060 Costa di Mezzate (BG)
Phone: 0039-035-682299 * Fax: 0039-035-687791
e-mail: [email protected] * http://www.airtorque.it
Modifications reserved. Date 01.2005.
No guarantee for accuracy.
Older data sheets are invalid.
Maintenance
907e
