Azbil VDD Series, User Manual

Page: 23 / 36

Azbil Corporation
9
Fit-in type
Bayonet type
Compressor
Diaphragm
Slots
Compressor
Bayonet pin
Diaphragm
Figure 4-1 Types Of Couplings Between Diaphragm and Compressor
(2) Attach the spindle to the diaphragm unit of the valve body section.
(3) Apply grease to the surface of the spindle, O-rings, and threads of the bolts and
nuts. Assemble the diaphragm unit, bonnet, and valve body by tightening the
nuts to the torque shown in Table 3-3 while checking the position of the edge
of the diaphragm. Tighten the nuts evenly in a diagonal pattern using a wrench.
(4) For a PTFE diaphragm, the valve body and the diaphragm will be sealed better
if the bolts and nuts are tightened further to the torque shown in Table 3-3 after
4 hours or more have passed since the first tightening.
When tightening is complete, carry out the pressure resistance test shown
below to check for leakage. If bolt or nut threads are damaged due to repeated
maintenance, the required tightening force may not be achieved even if they are
tightened to the torque shown in Table 3-3. Be sure to carry out the pressure
resistance test to check for leakage before use.