3 - 2
Operation
leaks, (no matter how small), detected at, or down-
stream of the dryer outlet MUST BE FIXED to ensure
that the dryer will provide a continuous supply of pro-
cess gas at specified dew point, to intended points-of-
use.
IMPORTANT: Water molecules can diffuse through
a pinhole-size leak even though pressure inside the
piping is several hundred PSIG. It is not uncommon
to have a minute pinhole leak in a gas line cause an
increase in dew point from -40°F to -10°F at a dis-
tance of forty or more feet downstream of the leak.
13. SLOWLY open the customer-supplied System Outlet
Isolation Valve, while monitoring the Outlet Pressure
Gauge (if dryer so-equipped). DO NOT permit the
Dryer's Outlet Pressure Gauge to exceed a 5% drop
in pressure while pressurizing downstream piping.
14. Close the customer-supplied System Bypass Valve (if
installed).
15. Open and adjust the Moisture Indicator’s Bleed Valve
until a very slight, continuous gas bleed is felt ex-
hausting from the bleed valve’s exhaust port. Ensure
that the granular indicator crystals remain motionless
after final adjustment.
16. Energize the dryer’s electrical power supply.
17. PURGE SETTING AND ADJUSTMENT
a) Locate the Critical Orifice Calibration Curve in
Appendix A of this manual.
b) To calculate purge flow consumption on the criti-
cal orifice curve:
Inlet Flow (SCFM) × 14.7 PSIG
× 1.15 = Purge (SCFM)
Inlet Pressure (PSIG) + 14.7 PSIG
Cross the Purge Flow requirement calculated
above to the same number on the Critical Orifice
Calibration Curve. Follow this line vertically and
then horizontally once intersection is made with
the curve line to find the actual purge pressure
setting.
18. Locate the Purge Adjusting Valve. Slowly rotate
dryer’s Purge Adjusting Valve until the Purge Pres-
sure Indicator indicates the calculated purge pressure
setting. (See following Note).
Note: The purge pressure can only be read and ad-
justed when an off-stream desiccant chamber has
depressurized for regeneration. (When the off-
stream chamber is pressurized, the Purge Pressure
Indicator will read “system pressure”.)
For dryers with the OPTITEK 2 EMS Energy Manage-
ment System: During operation in the Energy Man-
agement Mode, the off-stream chamber may remain
pressurized (in ENERGY MANAGEMENT ACTIVE).
If this condition is noted, proceed as follows to adjust
purge pressure.
a) Open Dryer Control System Enclosure. Locate
DIP switches on MEC CPU Board.
b) Switch DIP switch position 7 to OFF position
(down). De-energize dryer’s electrical power
supply for approximately fifteen (15) sec-
onds; then re-energize. Dryer is now in Fixed
Cycle Operation. The off-stream chamber will
depressurize to atmosphere for regeneration.
c)
Calculate and set purge pressure as previously
instructed.
d) Return DIP switch position 7 to ON position. De-
energize the dryer’s electrical power supply for
approximately fifteen (15) seconds; then re-ener-
gize. Dryer should be in Optitek Energy Saver
Mode.
19. The Start-Up procedure for models OP15 through
OP200 is now complete. Proceed to the Normal Op-
eration Checks section of this manual for final opera-
tional checks and adjustments.
Dryer Models OP250 and OP300
1.
Close any manual vent or drain valves installed in
prefilter and afterfilter assemblies.
2.
If the prefilter assembly utilized was factory-equipped
with an automatic drain valve or drain trap, inspect
for, and remove pipe plug or cap which may have
been installed in drain port for shipping purposes.
3.
Ensure that all associated pipe and tubing connec-
tions, flanges, unions, plugs, mounting bolts, pipe
hangers, etc., have been checked tight and/or prop-
erly secured.
IMPORTANT: It is recommended that the System's
process gas output not be consumed or used at the
intended points of use until the Start-Up and any re-
lated adjustments have been completed, and the sys-
tem is producing process gas of the required quality.
The quality of the process gas should be verified
through test and analysis when a specific quality pro-
cess gas is required.
4.
Refer to the applicable drawings which accompany
this manual as necessary for component identification
and location while conducting start-up and operational
procedures.
Note: If your dryer cannot be started, or fails to start
due to special installation or other problems, contact
your local General Pneumatics Sales Representative
for assistance.
