Parker Pneumatic
DD Series Inline Desiccant Dryers

Key Features

  • Compact size for point-of-use applications
  • Drying efficiency down to -40°F pressure dew point
  • Easily and quickly serviced
  • Sightglass in bowl to monitor desiccant
  • Built-in particulate after filter prevents downstream dust
  • No electricity needed
  • Low pressure drop
  • No purge air lost as with other dryer types
  • Check valve required on inlet
  • Desiccant must be ordered separately
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Inline desiccant dryers are a convenient and cost effective means of ensuring your sensitive intermittent pneumatic applications are never exposed to damaging moisture.

As the wet compressed air enters through the inlet, the air travels down through the bed of desiccant which adsorb the water vapor and aerosols. The silica gel desiccant beads will reduce the humidity down to a -40°F pressure dew point.

After the moisture has been removed, the dry air passes through a sintered bronze filter element (eliminating dust downstream), up the tube and out the outlet port.

As the desiccant becomes saturated with moisture, the dew point will begin to rise. This is evident when the blue silica gel desiccant beads in the sight glass change to pink, indicating the need for desiccant replacement. Simply remove the flange and bowl and replace with new desiccant or regenerate saturated desiccant by heating to 275°F.

  • Optimum working temperature Below 100°F
  • Operating temperature 32°F to 180°F (0°C to 82°C)
  • Operating pressure 0 to 300 PSIG Max (21 bar) 

Installation tips

  • Always place a moisture separator / particulate filter to remove bulk moisture and a coalescing filter to remove oil upstream of desiccant dryer. Desiccant coated with oil will not adsorb oil.
  • Automatic drains should be used in prefilters
  • A spring ball check valve should be installed at the dryer inlet to maximize the life of the desiccant.