18
Pub. No. OM-A-10E — April 2004
Mufflers
Purge mufflers are installed to reduce the noise level. The
mufflers tend to plug up and increase back pressure over
time due to oil carryover and contaminants from
compressor, or due to desiccant dust at the initial start-up.
To eliminate back pressure, replace muffler after three
months, or when the back pressure increases in the
regenerating tower.
PB SERIES HEAT REACTIVATED BLOWER
PURGE AIR DRYER MAINTENANCE
General
During the first month clean or replace the pilot air filter
element and repeat periodically. Also clean the exhaust
mufflers. Replace mufflers if the tower pressure gauge
reads any back pressure during the regeneration cycle.
No lubrication is required for any system.
Check intake filter on the blower, replace if necessary.
Daily
Check auto drain on prefilter every shift.
Weekly
1.
Check the cooling flow pressure setting.
2.
Check the dryer’s sequence of operation and valve
operation.
3.
Check the operating conditions; inlet pressure, inlet
temperature and the flow rate.
4.
Check the moisture indicator. BLUE color indicates
DRY conditions. If the color is PINK, refer to the
moisture indicator chart on alarm conditions for
probable cause.
5.
Check the purge mufflers for blockage. Possible
indication is back pressure on tower under
regeneration. Replace if necessary.
6.
Check the pressure drop across prefilter and after-
filter. Replace the elements when the differential
reaches 5-10 PSID.
Monthly
1.
Check the pilot air filter element. Replace if
necessary.
2.
Check the blower intake filter. Replace if necessary.
Three Months
1.
Every three (3) months, check for any leaks in the
inlet and/or check valves indicated by air coming
through the exhaust mufflers when the blower is off.
2.
Check the prefilter and afterfilter elements for
excessive clogging or possible damage. Replace as
necessary.
3.
Blow down relief valves.
4.
Check outlet dewpoint conditions.
Twelve Months
1.
Close the inlet and outlet valves on the dryer or
bypass the dryer and completely depressurize the
dryer system. Open the desiccant fill port and check
visually. If desiccant is contaminated with oil or
broken, replace the desiccant.
2.
Check for leaking check valves per Table 1
symptoms C & D in Troubleshooting Guide. Repair
or replace as necessary.
3.
Remove the inlet switching valves and purge exhaust
valves. Clean and replace worn out seats and seals.
4.
Inspect the pilot air cylinders for leaks or worn out
seals. Repair or replace as necessary.
5.
Check repressurizing valve. Repair or replace as
necessary.
6.
Check pilot air solenoid valves for possible defects.
Dewpoint Sensor (Optional)
It is recommended to recalibrate the sensor probe
annually to maintain accuracy. Contact your local
distributor or factory for exchange policy. See Page 17 for
calibration and sensor probe replacement information.
Mufflers
Purge mufflers are installed to reduce the noise level. The
mufflers tend to plug up and increase back pressure over
time due to oil carryover and contaminants from
compressor, or due to desiccant dust at the initial start-up.
To eliminate back pressure, replace muffler after three
months, or when the back pressure increases in the
regenerating tower.
Disconnect power and depressurize the
dryer completely before starting mainte-
nance procedures.
