9
DRYVAC 25/50/100 P Manual
GA 01.414/2.02 - 1/97
2 Installation
2.1 Adapting the Pump
to the Process
Warning If the DRYVAC has pumped hazard-
ous gases, you must determine the
nature of the hazard and take the ap-
propriate safety precautions. Comply
with all safety regulations. Take ad-
equate safety precautions before
opening the intake or exhaust.
The DRYVAC is delivered set up for the processes of
group B in Table 1 – unless specified otherwise by the
sales order . This setup opens the purge-gas supply to
theindividualpump stages.
If your process is in group A of Table 1, you must re-
move the cover panels of the pump, and reverse the
purge-controlplate asdescribed inSection 2.1.1.
2.1.1 Converting to ETCH Processes
For the ETCH processes listed in group A of Table 1, re-
verse the purge-control plate. Turning the plate so that
its"ETCH"side facesout shuts of fthe purge-gassupply
tothe pumpstages.
If LTO processes were being run with the CVD setting,
follow the procedure in Section 2.1.3; however , replace
the installed nozzle of the 3rd pump stage with a ∅
0.6 nozzle.
Reverse the purge-control plate as follows (see Fig-
ure 6):
1. Open the 1/4-turn retaining clips on top of the
pump, and take of f the two top covers.
2. Open the four 1/4-turn retaining clips on the rear
panel, and take of f the panel.
3. Unscrew the socket-head capscrews holding on
the side panels, and remove panels.
4. Unscrew the eight socket-head capscrews of the
purge-controlplate.
5. Turnoverthepurge-controlplate, andreinstallitsothat
thesidemarked“ETCH”isvisiblefromtheoutside; en-
surethatitsrubbergasketisalignedcorrectly .
6. Reassemblethepump cabinet.
Section2—Installation
2.1.2 Converting from ETCH to CVD
Processes
When converting from ETCH to CVD processes (the
processes of groups B, C and D in Table 1), follow the
procedure in Section 2.1.1; however , the purge control
panelmust be turnedso thatthe word CVDis facingout.
2.1.3 Converting to LTO Processes
For LTO processes, the nozzle of the 3rd pump stage
(6/4 or 6/7) must be replaced by the nozzle enclosed
separately with the pump. Replacing this nozzle in-
creasesthe purge gas flow inthe 3rd pump stage.
Replacethe nozzle as follows(see Figure 6):
1. Open the 1/4-turn retaining clips on top of the
pump, and take of f the two shells.
2. Open the four 1/4-turn retaining clips on the rear
panel, and take of f the panel.
3. Unscrew the socket-head capscrews holding on
the side panels, and remove panels.
4. For DRYVAC 25/50 pumps only , remove the tube
connector (6/1) from the connection block (6/3).
5. Unscrew the eight socket-head capscrews of the
purge-control plate (6/2 or 6/8), and remove plate.
6. For DRYVAC 25/50 pumps only , pull of f the connec-
tionblock (6/3) from the pump.
7. Unscrew the ∅0.6 nozzle (6/4 or 6/7); then screw
in the ∅0.8 nozzle.
8. For DRYVAC 25/50 pumps only , reinstall the con-
nection block and tube connector . Be careful not
to damage the O-rings on the connection block.
9. Install the purge-control plate so that the side
marked "CVD" is visible from the outside. Observe
the correct alignment of the sealing strap.
10.Reassemble the pump cabinet.
2.1.4 Main Inert Gas Valve
Standard DR YVAC P models have a 24 V AC/DC main
inertgas valve. However ,this valveis lockedin theopen
bypass position (manual override). In this position, the
purgewillflowcontinuously .
Referto Section 2.3.1for instructions ifyou want touse
24 V to open and close this valve.
