To Lubricate The Vent Valve O-Ring - HP 5973 Hardware Manual

4

To lubricate the vent valve O-ring

To lubricate the vent valve O-ring
Materials needed:
Cloths, clean (05980-60051)
Gloves, clean, lint-free
Grease, Apiezon L, high vacuum (6040-0289)
O-ring, vent valve (0905-1217) - replace if the old O-ring is worn or damaged
The vent valve O-ring needs a thin coat of lubrication to ensure a good vacuum
seal and smooth operation. If the vent valve O-ring does not turn smoothly, or
does not seal correctly, lubricate it using this procedure.
& $ 8 7 , 2 1
Vacuum seals other than the side plate O-ring and vent valve O-ring do not need to be
lubricated. Lubricating other seals can interfere with their correct function.
1 Vent the MSD (page 52).
2 Completely remove the vent valve knob.
3 Inspect the O-ring.
If the O-ring appears damaged, replace it.
4 Use a clean, lint-free cloth or glove to spread a thin coat of high vacuum
grease on the exposed surface of the O-ring.
& $ 8 7 , 2 1
Excess grease can trap air and dirt. Grease on surfaces of the O-ring other than the exposed
surface can trap air, resulting in air spikes during operation.
5 Use a clean, lint-free cloth or glove to wipe away excess grease.
If the O-ring looks shiny, there is too much grease on it.
142
Maintaining the MSD
large (8650-0030)
small (8650-0029)