Veeco MS40 Operation And Maintenance Manual page 93

Servicing the Fine, Rough & Reverse Valves
CAUTION
Vacuum Instrument Corp.
2099 Ninth Avenue
Ronkonkoma, NY 11779
631.737.0900
1109-186-00 Rev. C
10. Replace the spring into the plunger.
11. Replace the plunger into the valve coil.
12. Replace the valve assembly onto the valve block. Be very careful
not to pinch the O-ring. Reattach the four screws and washers.
13. Reattach the two wires onto the proper electrical connectors.
1. Vent the entire system. Follow the procedure stated in Section 4.6.
3. Open the rear panel by turning the captive screw at the top of the
panel 1/4 turn counterclockwise and gently lowering the door.
4. Remove the two wires from the electrical connectors on the valve.
Make note of which wire is connected to each metal prong (the fine
and reverse valves: the yellow wire is connected to the upper
prong/the striped wire to the lower prong; rough valve: the white
wire to the upper prong, the striped wire to the lower prong and the
green and yellow wire to the outer prong).
5. Remove the four screws and washers. Remove the valve assembly.
6. Remove the plunger and spring out of the valve coil.
7. The valve's O-ring is in the valve block. Remove it with a plastic
or other non-metallic instrument. Do not use metal or any other
hard instruments as they may scratch the O-ring groove. Wipe the
O-ring with a lint-free cloth and check each carefully for nicks,
dents or flat spots. Replace when necessary.
8. Wipe the seat on the valve block with a clean, lint-free cloth to
remove any contaminants. If necessary, a small amount of alcohol
may be used on the valve block.
Acetone or alcohol is destructive to rubber surfaces such as
the valve's O-ring. When cleaning rubber surfaces use a
clean and dry lint-free cloth.
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