Van Air Systems D12-D36 - Manual (Page 6)

PAGE 6
3.1 START UP PROCEDURES
Close the inlet and outlet isolation valves. Open the bypass
valve and manual drain valve.
Open the outlet isolation valve SLOWLY and allow some air to bleed
through the manual drain valve; then close the manual 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 manual drain valve. Once the vessel starts to pressurize, the
manual 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.
3.2-A DAILY DRAINING
The accumulated solution in the bottom of the dryer should be
drained at least once every 4 to 8 hours of operation.
Depending on 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.
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 is dependent 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 4.4-B for estimated consumption rates and
refilling instructions.
IMPORTANT
Use VAN AIR desiccant only. Filling dryer with any
other material will void the warranty.
SECTION 3 OPERATION
3.3 USING THE SIGHT WINDOWS
WARNING
IF THE SIGHT WINDOWS ARE DAMAGED IN ANY WAY,
THEY MUST BE REPLACED IMMEDIATELY WITH VAN AIR
PART NO. 26-0104 only. REFERENCE SECTION 4.3.
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.
SECTION 4 MAINTENANCE
4.1 DAILY PROCEDURES
If an automatic drain valve was not installed on the dryer, the
accumulated drain solution from the bottom of dryer must be drained
after every 4 to 8 hours of operation . 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.