Maintenance and Repair 4 - 1
4.1 Preventative Maintenance
Schedule
Weekly
1. Check the following operating conditions:
a) Purge pressure setting (during regeneration)
b) Inlet pressure
c) Inlet flow rate
d) Inlet temperature
For optimum dryer operation and performance, these
recorded parameters should correspond as close as
is possible to the design operating conditions and
specifications noted on the Dryer Specification Label
(located on inside cover of dryer control enclosure).
2. Visually inspect the Moisture Indicator (if dryer is so-
equipped) for a BLUE (dry) indication. If the indicator
is PINK (wet) in color, refer to the Troubleshooting
Guide and conduct checks listed for the Moisture In-
dicator.
3. Check the dryer’s Indicator Panel for the presence of
any illuminated alarm indicators. If an alarm indicator
is illuminated, refer to the Troubleshooting Guide.
4. Check the pressure drop (differential pressure) across
the Prefilters and Afterfilters. Prefilter and afterfilter
cartridges should be replaced BEFORE a differential
pressure of 10 PSID is exceeded.
CAUTION: Each component of a Deltech Regenera-
tive Desiccant Dryer System has been selected to
compliment the performance of the other components
of the system. Therefore, use of unauthorized parts
or supplies or improper operation will degrade system
performance.
5. Check operation of the prefilter's automatic drain
valve. This component must function properly to
maintain filter efficiency and prevent premature desic-
cant failure induced by liquid and oil carry over from
the prefilter, due to a clogged or inoperative automatic
drain valve.
Quarterly
Check the dry gas outlet dew point. A precision Dew Point
Analyzer is required to read the exact dew point. The ana-
lyzer should be connected as close to the dryer outlet as
is possible. Test piping or tubing used to connect the ana-
lyzer to the gas system must be metallic, as rubber and
certain plastics contain or permit moisture diffusion from
the ambient air and can cause a false high dew point indi-
cation. Alnor, Beckman, Shaw and several other brands of
precision dew point instruments are available.
Semi-Annually
WARNING!
Ensure that the Dryer and any associated Prefilters
and Afterfilters are valve isolated and fully depressur-
ized before attempting to remove or disassemble
any components or subassemblies. Failure to do so
may result in serious personal injury and/or equip-
ment damage.
CAUTION: Each component of a Deltech Regenerative
Desiccant Dryer System has been selected to compliment
the performance of the other components of the system.
Therefore, use of unauthorized parts or supplies or im-
proper operation will degrade system performance.
1. Inspect the Pilot Gas Filter Cartridge and replace if
the used cartridge appears clogged, dirty or exces-
sively corroded.
2. Inspect the Prefilter Cartridges for clogging, exces-
sive corrosion, cracked or damaged end seals or high
pressure drop (differential pressure exceeds 10
PSID). Replace cartridges if necessary.
3. Inspect the Afterfilter Cartridges for clogging, exces-
sive corrosion, cracked or damaged end seals or high
pressure drop (differential pressure exceeds 10
PSID). Replace cartridges if necessary.
4
Maintenanceand Repair