PAGE 8
PRINTED IN THE U.S.A.
MAINTENANCE & TROUBLESHOOTING
SECTION 9
9.1 DAILY INSPECTION
The following procedures should be performed daily:
• Check the dryer operating conditions, inlet temperature, ambient
temperature, inlet pressure and inlet flow.
• Monitor the dryer for one complete cycle. Make sure that it is
operating properly. Visually check the dryer and piping for damage.
• Check the purge muffler. Purge air should be exhausting from
the valve. If oil is present, the dryer and air system may be
contaminated with lubricants.
• Inspect all upstream equipment, aftercoolers, separators, drains
and filters. Make sure that all bypass valves are tightly closed.
• Check the prefilter(s) for proper draining. If the prefilter is not
equipped with an automatic drain, it must be manually drained.
Check the pressure differential indicator on all prefilters and
afterfilters. If the differential pressure is unacceptable, replace the
elements.
9.2 SCHEDULED MAINTENANCE
12 MONTHS
• Replace purge muffler element
• Replace the control air filter element
24-60 MONTHS
• The desiccant in the towers should be replaced every two to five
years. The life of the desiccant will vary depending on the inlet air
conditions. Systems with excessive contaminants and/or inad-
equate filtration will decrease the life span of the desiccant
drastically. Once the desiccant is contaminated with lubricants, it
must be replaced.
SHUTDOWN
SECTION 8
8.1 SHUTDOWN PROCEDURES
Shutoff the air supply to the dryer. If bypass piping and valves were
installed, close the inlet and outlet isolation valves and open the
bypass valve. Let the dryer cycle until it is totally depressurized.
9.3 DESICCANT REPLACEMENT
WARNING
DO NOT ATTEMPT TO REMOVE ANY ITEM UNTIL ALL AIR
PRESSURE IS OUT OF THE VESSEL. CHECK ALL TOWER
PRESSURE GAUGES, MAKING SURE THAT THEY ARE AT 0
PSIG AND THAT INCOMING PRESSURE HAS BEEN TURNED
OFF.
ALWAYS WEAR EYE PROTECTION AND GLOVES WHEN
HANDLING THE DESICCANT. DUST FROM THE DESICCANT
MAY CAUSE EYE AND SKIN IRRITATION. AVOID BREATHING
THE DUST AND PROLONGED CONTACT WITH THE SKIN.
FIRST AID IN CASE OF EYE CONTACT, IMMEDIATELY FLUSH
EYES WITH PLENTY OF WATER FOR AT LEAST 15 MINUTES.
CONSULT A PHYSICIAN.
Take dryer off stream following the
SHUTDOWN PROCEDURES IN
SECTION 8.
For HLS-55 and HLS-80:
Carefully disconnect the inlet and outlet piping assemblies from the
dryer and process piping. Disconnect the piping assemblies at the
union connections. Unthread the bushing/diffusers from the bottom of
each vessel to drain the old desiccant.
Remove any oil, dirt, or scale from the towers and piping. Do NOT
weld, grind or sandblast the vessels. The vessels may be steam
cleaned internally and externally to remove dirt and oil.
CAUTION
Make sure that the towers are clean to prevent contamination of
new desiccant.
Reinstall the bushing/diffusers in the bottom of the vessels. Install the
inlet piping assembly. Apply pipe thread sealant as necessary.
Remove the bushing/diffusers from the top of the vessels. Load
desiccant through these ports.
REFER TO SECTION 3.1 FOR
PROPER DESICCANT AMOUNTS.
Reinstall the bushing/diffusers in the top of the vessels. Install the
outlet piping assembly. Reconnect the dryer to the process piping.
Apply pipe thread sealant as necessary.
Follow
START UP PROCEDURES IN SECTION 5.1
to start up and place
dryer in operation.
For HLS-120 and HLS-150 fill and drain ports are provided, so piping
disassembly is not required.
9.4 CONTROL AIR FILTER REPLACEMENT
Close the dryer inlet and outlet isolation valves (and open bypass
valve if provided). Turn off the power and completely depressurize the
dryer.
WARNING
DO NOT REMOVE THE FILTER BOWL FROM HEAD UNTIL
HOUSING IS COMPLETELY DEPRESSURIZED.
After all pressure is out of the dryer, grasp the filter bowl firmly. While
pushing the bowl upward, turn it clockwise to remove it from the filter
head.
Unthread the used element from the head. Discard the used element
properly.
Remove new element from the shipping package. Thread the new
element into the filter head.
Position the bowl in the filter head. While pushing the bowl upward
into the head, turn the bowl counterclockwise to lock it in place.
Following the start up procedures for the dryer, place the dryer on
stream.
