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Please consult the factory PRIOR to installing a unit for any application other than air
or inert gases. Use with certain liquids or gases could be harmful to the unit, result in a
combustible condition, or cause hazardous leakage. In the event of a misapplication,
the product warranty is voided and PUREGAS will assume no responsibility or liability
for any resulting loss.
Operation of PHF, PCDA, PHCA and PCME Models
The PHF, PCDA, PHCA and PCME models utilize a common die-cast aluminum
manifold, to which the desiccant towers (chambers), 3-way solenoid valves, timer, and
other components are attached. The inlet air passes upward through the desiccant
tower immediately above the energized DC solenoid valve. When the air reaches the
top of the tower, it is redirected back down the return air tube in the center of the tower,
through the open check valve, and into the outlet passageway. Most of the air is
delivered to the application, while a portion is diverted for purging the off-line desiccant
tower. This air passes through the fixed orifice beneath the off-line tower, upward
through the air tube, and then downward through the desiccant, removing the
accumulated moisture and/or other contaminants. These unwanted elements of the gas
stream exit the unit through the purge port of the de-energized solenoid. This process is
reversed every 30 seconds to provide a continuous source of pure, ultra-dry air.
FIGURE 1: OPERATION OF PHF, PCDA, PHCA AND PCME MODELS
Desiccant
Air Tube
Orifice
Tower 1
Tower 2
Check
Valve
(Closed)
Check
Valve
(Open)
Wet Gas
Inlet
Dry gas
Outlet
To
Atmosphere
3-way
Valve
Solenoid
