Azbil VDD Series, User Manual

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Azbil Corporation
8
Table 4-4 Connection methods and diaphragm shapes
Diaphragm material
Valve nominal
diameter (inches)
Connection method Shape
Rubber
1/2 ‒ 3/4
Fit-in type
Normally open
1 ‒ 4
Screw-in type
PTFE 1/2 ‒ 4
Backing
of Rubber
PTFE
Bayonet type
Normally closed
Inspection before assembly
Check the disassembled parts for the types of damage listed below. If any damage
is found, replace the part. When ordering parts, please inform us of the production
No. of the valve, which is printed on the nameplate.
(1) Valve body: corrosion or wear of the wetted parts, cracks on the lining
(2) Diaphragm: deterioration, wear, cracks
(3) Spindle: damage on the sliding parts
Assembly procedure
(1) Attach the diaphragm to the compressor.
(a) Fit-in type: Wet the protrusion of the diaphragm with water, and push it
into the hole of the compressor. (See Table 4-4.)
(b) Screw-in type: Screw in the diaphragm until its rubber part comes
into contact with the indentation in the compressor. Then, unscrew the
diaphragm to the level where it is aligned with the bonnet hole when the
valve is assembled.
(c) Bayonet type: Align the pins with the compressor slots, fully insert, and then
turn the diaphragm 90° clockwise or counterclockwise. (See Table 4-4.)