Instruction Manual
W32- Series Medium-Vertical Compressors
Page I - 8.
I – 6. Principles of Operation
1st Stage Cover
3rd Stage Cover
1st Stage Valve Ass'y
1st Stage
Connecting Rod
Connecting Rod
Connecting Rod
Piston Ass'y
Piston Liner
1st Stage
Piston Ass'y
(1st Stage)
(2 nd Stage)
(3rd Stage)
(3rd Stage)
(3rd Stage)
Cylinder
Valve Head
Valve Head
Discharge Valve Ass'y
Inlet Valve Ass'y
Dicharge Valve Ass'y
Inlet Valve Ass'y
(2nd Stage)
(3rd Stage)
(3rd Stage)
(3rd Stage)
(2nd Stage)
(2 nd Stage)
Cylinder (2nd Stage)
Piston Ass'y (2nd Stage)
Guide Cylinder (2nd Stage)
Crankcase
#7786
Fig. 5 W32 com
pressor unit section.
The P & I diagram have to be reviewed carefully
to understand the principle of operation. The air
is drawn at atmospheric pressure, through the
inlet filter (see
Fig.5
) into the 1
st
stage cylinder on
the up-stroke of the piston (see
Fig.5
). The up-stroke
motion of the piston will cause compression and the air
will be forced out of the cylinder through 1
st
stage
discharge valve (see
Fig.5
). Air will than pass through
the intercooler tubes between the 1
st
and 2
nd
stages
and into the 2
nd
stage compression chamber. Here, the
air is compressed to the 2
nd
stage compression level
and forced through the 2
nd
stage 2
nd
stage
inter moisture sep 3
rd
stage inlet valve
into the 3
rd
stage cylinder. Here, the air is compressed
to the final pressure level and forced out to the
aftercooler, oil & water separator (pre-filter), than
passing through a check valve enters the purifier
chamber, where it is purifier and prepared to be used
for breathing purposes. A priority (or minimum
pressure valve) is installed downstream the purifier;
this valve prevents the air to exit the purifier until the
pressure builts to approximately 180 bars (2610 psi), a
pressure level where the purification process is more
efficient than at lower pressures. The air is than ready
to be directed to a filling panel and with proper
connections to the cylinders to be filled.
The intercoolers and the aftercoolers are desighed to
dissipate the head generated from the previous
compression cycle, redusing the air temperatures,
allowing the water vapors to condensate and settle in
the bottom sections of the moisture separators. The
moisture separator and the oil & water separator (pre-
filter) are equipped with an automatic drain valve. The
drain valve is a 3 way pneumatic valve controlled by a
3-way solenoid valve. This solenoid valve sends or
removes the control air from the drain valves,
thusletting them to open or close. The solenoid itself is
controlled by a sequential timer relay in the electrical
panel. The dual time adjustment on this relay allows to
adjust the duration (t
1
~ 15 min) during which the
solenoid will remain energised (=the drain valve will
remain closed), and the length of time (t
2
~ 6 seconds)
during which the solenoid will become de-energised
(=the drain valve will open and perform the drain
function).
The compressor starts and stops with automatic
regulation by a
pressure switchgage
(see
section I-8
for adjustments and functional details).
