Refrigeration System Accessories : Liquid Line Filter Drier

 Liquid Line Filter Dryer:

1. Purpose:

   • Cleans up system contaminants.
   • Contains screens and fiberglass filters to remove dirt and debris.
   • Includes a desiccant, typically silica-based, to remove moisture and acid.

2. Installation:

   • Installed when the unit is set up and remains unless the system is opened for repair or contamination.
   • Should be replaced when in doubt, especially if sweating, condensation, or frost appears on the body, indicating obstruction and pressure drop.

3. Identification:

   • Manufacturer-specific codes.
   • 'C' indicates catch-all line.
   • 'EK' means extra clean.
   • First two numbers represent cubic inches of capacity (e.g., 03 for 3 cubic inches).
   • Last number indicates line size in eighth-inch increments (e.g., 2 for 1/4 inch, 3 for 3/8 inch).
   • Last letter shows connection type (S for sweat, none for flare).

4. Direction and Pressure Rating:

   • Directional flow indicated by an arrow on the body.
   • For R-410A systems, use dryers rated for 600 PSI minimum.

5. Desiccant Types:

   • Activated Alumina: High acid removal, moderate moisture capacity.
   • Molecular Sieve: High moisture capacity, low acid removal.
   • Silica Gel: Only removes water, used in inexpensive dryers, often factory-installed in air conditioners.

6. Choosing the Right Dryer:

   • Determine system tonnage.
   • Know the liquid line pipe size.
   • Identify connection type (braze/sweat, flare, flange).

Example:

• For a 3-ton air conditioner with a 3/8 inch liquid line:
  • Tonnage capacity: 3 to 6 tons.
  • Line size: 3/8 inch.
  • Connection type: sweat (requires brazing).