Azbil VDD Series, User Manual

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Azbil Corporation
11
4.4 Mounting the Actuator on the Valve Body
(1) Place the actuator on the valve body and tighten the yoke nuts firmly.
(2) Connect air piping to the actuator to provide a pneumatic control signal.
A pressure regulator may be used for the pneumatic control signal source.
(Connect the air piping to the upper diaphragm case for direct-action actuators
or to the lower diaphragm case for reverse-action actuators.)
(3) Lower the spindle until the diaphragm is fully seated on the weir of the valve.
For direct-action actuators
(4) Set the air pressure to the spring range upper limit shown in Table 4-6.
(5) Increase the air pressure to the supply pressure and check that the actuator stem
moves in response. (This is a margin for stroke.)
(6) Reduce the air pressure slightly and set the air pressure to the spring range
upper limit again. Then, tighten the hex bolts that hold the stem connector so
that the threads of the actuator stem and the spindle are engaged.
For reverse-action actuators
(4) Set the air pressure to the spring range lower limit printed on the nameplate.
Check that the actuator stem moves 1–2 mm in response. (This is the margin
for the stroke.)
(5) After increasing the air pressure slightly, lower it to the spring range lower
limit again. Then, tighten the hex bolts that hold the stem connector so that the
threads of the actuator stem and the spindle are engaged.
Table 4-6 Spring range of direct-action actuators
Connection diameter (inches) Spring range (kPa)
1/2 20–53
3/4 20–64
1 20–74
1-1/2 20–96
2 20–82
2-1/2 20–95
3 20–81
4 20–102