Dichot Inlet Cleaning

 

Purpose:  The dichot inlet should be cleaned each month, at the same time as the FRM, PCM and other particle inlets.

 

Required Equipment:  disposable gloves

           squeeze bottle filled with distilled water

           Kimwipes

           Krytox vacuum grease

           Site Log

 

Reference:  SOPMAN

 

  1. Put on a pair of disposable gloves.  Remove the dichot inlet by gently lifting the complete inlet off of the aluminum sample tube.
  2. Disassemble the upper and lower halves of the inlet by unscrewing counter-clockwise the top half from the lower half.  Note:  The upper half includes the top plate and the conical section beneath it; the lower half is cylindrical.   The two halves join together near the middle of the assembly.  Gently set the lower half on the shelter deck, where it won’t roll away.  Avoid getting any dirt or dust inside the lower inlet or on the threads.
  3. Inspect the screen at the top of the upper half for insects and dirt.  Clean the screen by inverting the upper inlet half and spraying the screen with distilled water.  Dry the screen with a kimwipe.  Be careful not to leave any lint or pieces of the kimwipe on the screen.
  4. Tear a kimwipe in half and fold to form a tampon about 3-4" long.  Moisten the kimwipe and push through the accelerator nozzle extending from the bottom of the upper half.  Twist the kimwipe back and forth several times to clean all inner surfaces of the accelerator nozzle.  Place the upper half gently on the deck.  Note:  Avoid damage to the top plate, as this will adversely affect the particle collection efficiency of the dichot.
  5. Spray a small amount of water into the lower inlet half and wipe off all interior surfaces.  Tear a kimwipe in half and fold to form a tampon about 3-4" long. Moisten the kimwipe and push through each exit tube.  Twist the kimwipe to clean each tube thoroughly.  Dampen a kimwipe and clean the downstream end of the lower inlet half.
  6. Place a very small dab of Krytox vacuum grease on the threads of the upper inlet half.  Work the grease around the threads to form a thin, uniform layer.  Apply a very thin film of grease to the two o-rings on the outlet end of the lower inlet half.  Wipe excess Krytox off your gloves and off the dichot inlet with a kimwipe.