Azbil VDC - O-Ring Replacement of Diaphragm Motor (See Figure 1-6, 1-7.)

Parts Replacement Azbil Corporation
6-6 VDC, VAC, VST, VAA - Diaphragm Control Valve
Remove clamp nut of the diaphragm plate. If actuator stem also rotates while doing
this, hold it by applying a wrench to the pointer lock nut. Remove diaphragm plate
and replace diaphragm
To reassemble, follow the above procedure in the reverse order. After
reassembling, apply a su󰀩cient amount of adhesive agent (semi-dry adhesive agent
for metals) to prevent air leak.
6-5 : O-ring Replacement of Diaphragm Motor (See Figure 1-6, 1-7.)
6-5-1 : For VA1R, VA2R or VA3R
Disconnect air connection. Turn spring adjuster clockwise until the spring is fully
slackened. Remove stem connector and disconnect actuator stem from valve
stem. Remove pointer lock nut and pointer by turning them. Remove hex bolt of the
diaphragm case assembly. Remove diaphragm case (upper). Lift out diaphragm,
diaphragm plate and actuator stem together. Remove “O-ring” with a marking - o󰀨
pin or like. Replace “O- ring”. During the replacement process, thoroughly clean the
groove in which “O - ring” is tted and sparingly apply silicone grease to the groove.
To reassemble, follow the above procedure in the reverse order. After reassembly,
adjust the valve lift and spring compression. For adjustment, follow the procedure
explained in Chapter 4.
6-5-2 : For VA4R or VA5R
Disconnect air connection. Turn spring adjuster clockwise until spring is fully
slackened. Remove hex clamp bolts of the diaphragm case assembly and then
remove diaphragm case (upper).
Remove clamp nut of diaphragm plate. If actuator stem also rotates while doing this,
hold it by applying a wrench to the pointer lock nut. Remove the diaphragm plate and
replace diaphragm
Remove the bolt on which O - ring is positioned. Remove O - ring from the bolt using
a scrubber or other tool.
Position the new O- ring. Before doing this, thoroughly clean the groove for the
O-ring and sparingly apply silicone grease to groove.
To reassemble, follow the above procedure in the reverse order. After reassembly,
adjust the spring compression. For adjustment, follow the procedure explained in
Chapter 6. “Control Valve Adjustment”, Item (b) “Spring Compression Adjustment”.