Van Air Systems D42-D84 - Manual (Page 6)

PAGE 6
4.1 DAILY PROCEDURES
After every 8 hour period of operation, drain accumulated solution
from the bottom of dryer. Open manual drain valve and allow the
solution to discharge from the dryer, then close the manual drain
valve securely.
4.2 MONTHLY PROCEDURES
Check the level of the desiccant bed by looking into the sight window.
If the top of the desiccant bed is level with the sight window, the
desiccant bed must be replenished.
Check the operation of all equipment installed before and after the
dryer.
Check the afterfilter element condition. If the pressure differential
across the filter is high (6 to 9 PSID), replace the element.
Inspect the hatch cover for signs of corrosion and/or leaks. Replace
the cover and/or gasket if necessary.
4.3 REPLACING THE SIGHT WINDOWS (P/N 26-0104)
WARNING
DEPRESSURIZE DRYER COMPLETELY BEFORE
REMOVING THE SIGHT WINDOW.
Using a pipe wrench, unthread the old sight window. Remove
all pipe sealant, rust or dirt from the coupling.
Apply a layer of pipe sealant to the threads of the new sight
window. DO NOT USE TEFLON TAPE. Tape may prevent
the sight window from threading into the coupling far enough.
4.4 DESICCANT SUPPORT GRID
If the grid becomes damaged, it can be replaced. The grid consists
of plastic grid pipes and steel top rings.
Should the grid require replacment, detailed instructions for
replacement will be provided with the new grid.
3.1 START UP PROCEDURES
Close the inlet isolation valve and open the bypass valve.
Open the outlet isolation valve SLOWLY and allow some air to bleed
through the drain valve; then close the drain valve. When the dryer
reaches normal operating pressure, SLOWLY turn the inlet valve to
full open position; then close the bypass valve.
If the vessel was installed without the bypass or isolation valves,
SLOWLY pressurize the air system. Allow some air to bleed through
the drain valve. Once the vessel starts to pressurize, the drain valve
can be closed.
Close the bypass valve. The dryer is now on stream.
CAUTION
Make sure that the dryer is not subjected to sudden flow
surges. Always open the valves slowly to permit gradual
equalization of pressure between the dryer and the air
supply lines.
3.2 OPERATING THE DRYER
The simple design of the single tower dryer allows for easy
operation. The dryer requires two procedures to ensure peak
performance.
On a new installation, continue to drain all downstream traps for
several days (or until no water is evident) after dryer is installed.
This period is required to dry out any accumulated water in the
compressed air system. Once the water is removed, the down-
stream traps should not need to be drained again.
3.2-B REFILLING THE DRYER WITH DESICCANT
During the VAN AIR drying process, the desiccant tablets dissolve
slowly. More tablets must be added to the supply when the top of
the bed drops to the sight window level (minimum level). Reference
FIGURE 5.
The desiccant consumption rate depends on several factors, such
as inlet temperature, flow, pressure and the type of desiccant being
used . With average conditions, the desiccant will usually need to
be added only two to three times per year when the dryer is
operating one shift per day. However, until the actual usage rate
is determined, check the bed level monthly.
Reference Section 4.5 for estimated consumption rates and
refilling instructions.
IMPORTANT
Use VAN AIR desiccant only. Filling dryer with any
other material will void the warranty.
WARNING
IF THE SIGHT WINDOWS ARE DAMAGED IN ANY WAY,
REPLACE THEM IMMEDIATELY WITH VAN AIR
PART NO. 26-0104 only. REFERENCE SECTION 4.3.
3.3 USING THE SIGHT WINDOWS
To check the level of the desiccant bed, look into one of the sight
windows. When the top of the desiccant bed is level with the sight
windows, the desiccant supply has dropped to the minimum level.
The bed must be replenished to raise the bed level to the maximum
level.
3.2-A DAILY DRAINING
The accumulated solution in the bottom of the dryer should be
drained at least once for every 8 hours of operation.
Depending upon actual operating conditions, the dryer may
require draining on a more frequent basis.
If an automatic ball valve type drain valve was installed on the
dryer, set the time cycle for every 4 to 8 hours. If a manual
drain valve was installed, it must be opened at least once every
4 to 8 hours to drain the dryer.
CAUTION
If the dryer is not drained regularly, it may become
flooded. Accumulated liquid may enter the air system and
cause damage to downstream equipment.
SECTION 3 OPERATION
SECTION 4 MAINTENANCE