Azbil VDC - Page 52

Parts Replacement Azbil Corporation
6-16 VDC, VAC, VST, VAA - Diaphragm Control Valve
2. Assembling piston unit, lift stopper and spring retainer
Step 1) Install eyebolts on threaded hole (M12 x 2) on the top of spring retainer 59
on the piston unit, suspend by crane and lift upward.
Step 2) While suspended upward, assemble lubricated O ring 8 and tape liner 7
on piston 57.
Step 3) Assemble piston unit in cylinder 21 from the top. See to it that the round
hole of rod 58 appears to the front.
Step 4) Assemble lift stopper O-ring 5 in the slot on the top of cylinder 21.
Step 5) Insert lift stopper 20 from the top and x by hexagon stay 4,9 (four). Screw
in on the ones of the same length diagonally.
Step 6) Assemble so that the hexagon stays 4,9 are t into bolt holes of spring
retainer 17.
Step 7) Fix spring retainer with hexagon head nuts (four)
Step 8) Install eye nuts 1 (two) on hexagon stay 4
6-6-7 : Assembly of Actuator without Manual Handwheel
When assembling actuator without manual handwheel, follow the procedure in
Chapter 4-3-3-5. Assembly of actuator with manual handwheel” disregarding the
inapplicable parts of the actuator.
Major Replacement parts
Actuator's parts have been designed to withstand prolonged usage. However, it is
recommended that the following parts be replaced in the intervals as given below:
Tape liner Every ve years
Bushing “
Seal washer “
Dust seal “ (to be replaced when disassembled)
Rod seal “ ( “ )
O ring “ ( “ )
Tightening Torque of Actuator Assembly
Table below shows the tightening torque of actuator assembly. Refer to Figure 6-14,
tightening torque of actuator's threaded parts.