Brooks On-Board 8, Инструкция по установке и обслуживанию

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4-6 ©2013 Brooks Automation Inc. Pub. No. 8040564, Rev. AA, 01/15/13 ECO No. 64541
Method 1 - Decontaminate all On-Board GLE Cryopumps
This procedure removes gaseous contamination from the helium circuit by
cooling each On-Board GLE Cryopump so the gaseous contamination is
frozen in the coldhead. Each On-Board GLE Cryopump is then
decontaminated in sequence. This procedure is outlined in
Figure 4-1 .
High helium gas pressure may be present within high vacuum pump systems and can cause
severe injury from propelled particles or parts.
1. All On-Board GLE Cryopumps on the same manifold should
have been running with second stage below 25K for at least 30
minutes. If not, then cool the remaining On-Board GLE
Cryopumps down and run for 30 minutes minimum after
reaching 25K to trap contaminants in the coldhead. Continue
with Step 2 even if any pump does not cool below 25K (its
performance may already be affected by contamination). Close
the high vacuum valves to isolate the On-Board GLE
Cryopumps from the vacuum chamber.
After Step 1 has been completed, all of the coldheads have been cooled and
the contaminant gases frozen in the coldhead.
2. Attach a regulator (0-400/0-3000 psig) and charging line to a
helium bottle (99.999% pure). DO NOT OPEN THE BOTTLE
VALVE AT THIS TIME.
3. Purge the regulator and charging line as described in Steps a
through d below. Use only 99.999% helium gas.
a. Open the regulator a small amount by turning the adjusting
knob clockwise until it contacts the diaphragm, turn the
adjusting knob so that the regulator is barely open.
b. Slowly open the bottle valve, and purge the regulator and
line for 10 to 15 seconds. Keep the helium flowing to
prevent re-contamination.
c. Loosely connect the charge line to the closed Hoke valve on
the maintenance manifold. Refer to Figure 4-3 .
d. Continue to purge the charge line for 30 seconds, and
tighten the charge line flare fitting onto the Hoke valve
while the helium is flowing.